why machining the groove wasn't an option? if i am not mistaken, unless the groove already touches the bottom, your ilustration would be correct, othervise you could simply remove some materials from the sides of the groove and it would fall deeper as e resoult untill it would actually touch the top of the rail, although it could also move side to side, it could have aded bonus of increasing the area of contact
Whenever I make a decision about working on this lathe, I'm biased towards any approach where I can most easily change my mind later. If this way had not worked out, I could have machined away the shims and tried the approach of machining the groove instead. They approach I tried ended up working out, and it didn't take away any options in future. If I had machined the groove first, and screwed it up, I wouldn't have any other option to try.
@@DJW1959Aus yes but can it really be aligned as is after shiming the base , i mean if it was aligned while being crucked on a wierd angle as it was, you will have to deal with it anyway, so it highly depend on how the tailstok was aligned before if it was at all. if it was then after shiming the base you may even have to mill it down. there is a lot of variables to work with when you are dealing with a column mounted on 2 pivit points and you modyfy even one of them
@@AdventureswithaVerySmallLathe fair point, it all depends on avalable setup options to machine it, i was just a bit at ods with the explanation in video. whatever works for you , still that plate looks like it is a bit small , was it the oryginal part of this lathe or there is no info about where it came from?
There is an issue that must be considered and that is the final distance between the bed and the center of the complete tail stock. It should be exactly 7 inches in this case. Actually, you should measure the height of the center of the headstock bore above the bed and then set the tailstock to that exact value. So if you get the base plate a bit too low you can always use large shims that cover most of the contact patch between the parts in the tailstock to bring it to that height.
I'm trying to learn to use metal working machines, too. I love having access to people with decades of experience and people as new to these tools as me. When folks like you demonstrate what you're trying, and include all your discoveries, mistakes, and successes it is a huge boon. Being able to observe mistakes I would have also certainly have made, processes I never would have thought of, or even things I know are wrong - it builds my skills and my confidence. If comments by other content creators are anything to go by, youtube can bring a lot of negative feedback. So, for what it's worth, I appreciate you and others who are willing to record, edit, and post content (a significant effort in itself) and put yourselves out there with what you've tried, wherever you are on your learning curves. Thanks!
Thanks for the feedback. Your confirmation makes it easier for me to include all the mistakes and inexperience, which can make working on these videos really nerve wracking.
With the caveat that I've never personally done any scraping - in the scraping videos I've watched (who would have thought my life would come to this?) they've always employed a cross-scraping pattern, whereas you appeared to be going at it from one direction only. A second pass at 90° to the first removes more material, and helps even-out the scraping marks, speeding things up and leading to a flatter surface. Keith Rucker is a master at this stuff.
Thanks Barty and Dan, this is a really good point. I did start off trying to scrape in alternating cross pattern, but the small area I was dealing with, and the other challenges I was facing distracted me, and I lost focus on making sure I did that. Working on the prism groove, the width of the area to be scraped was so small it was difficult to scrape at an angle at all.
Firstly, just make your own carbide tool by brazing a piece of carbide to anything. I prefer old pry bars. I've also never ground a piece of carbide in my life because of this. There are enough broken lathe bits or end mills that will be radiused if you need it. The radius make sense when your learning I guess but I can use a straight edge just like a radiused one. The negative rake is really the only necessity and that can be eyeballed. You are "theoretically" only supposed to be touching a single point of material anyway with the radius and all. Having done a bunch of scraping the hashed appearance is just that. Appearance. People can argue all they won't about how much oil it holds, cool, whatever you want to do in your spare time is fine. What the 90 pattern does stop you from doing is creating a bias that you can find yourself overlooking from only one side of the scraping tool. Ultimately you are looking for 40 touch points per square inch (minimum and maximum there does need a place for oil to be and you aren't looking to wring these surfaces together), since an inch by and inch is easiest to measure from one side to the other shooting up-down then diagonally is a very logical way to proceed. When I have done larger faces, I would start one direction then beyond move 15 degrees past 180 each time so as to not have a big hump or otherwise. When removing material I imagine myself, "printing" or rubbing the average value I am looking onto the surface where I want it. I am trying to to remove material to allow the not yet colored surface to slowly come up while trying that to preserve as much of that blue contact area as possible. Another source for surface plates are granite countertops. Those commercial companies spend a lot of money on those diamond bits to ensure those things are pretty flat. Maybe not truly parallel but flat for the size you are touching off. If you plan on doing any amount of scraping, once you get the bug you will start by scraping every tool you own then start considering scraping the disks on your brakes, if you go past this tool just get a cheap little machine shop surface place for $100 shipped. That way you know you are getting something that was toleranced. Everything else is just not going to be a toleranced surface plate, just like your carbide. Regardless, anyone will be hard pressed to find -anything-, I mean ANY TECHNIQUE that will give you a flatter surface than hand scraping. It's so worth picking up the skill if you have machinery of any kind. You will learn more in an hour with a carbide paint scraper or even a carbide endmill in your hand than you will a dozen hours of video. It's super simple to learn by doing and unbelievably valuable.
@@AdventureswithaVerySmallLathe You´ve done your part but may i suggest another method that i´ll try when my lathe comes in two weeks: Superglue sandpaper on the rails and go over it with the slide. Begin rough to go fine later on. That should work well as many guys told in the comment section under even more videos. Seems logical to me. I´ll fix the lathe absolutely leveled with a fine machinists bubble level. Then start the process. This way it should possible to see if the slide is squared all around. What do you [guys] think?
Thanks for bringing us along for the ride, sharing the good and the bad. Content producers like you infuse the rest of us with much needed knowledge without each of us having to learn the hard way.
Very much in agreement with going with the carbide scraper. I use carbide paint scraper blades too and for small hobby stuff like this, they are more than good enough. For a first go at it I think you did a great job.
Thanks! I honestly thought I'd get a lot of comments about using inferior carbide blades, but they seem to work fine to me, and the narrow width feels easier when working on small mini-lathe parts. Your mini lathe mod videos were a great source of background and inspiration, so I'm really glad you enjoy my videos too.
As I recall, this one was specifically bought as being unusually cheap and not from a decent re-seller (I forget whether it was in videos or in comments, but I think it was even speculated that this was specifically QC-reject parts assembled into a complete product). I recently bought a similar unit from a local reseller that sources them from a brand that *actually* does QC and it's NOTHING like this.
@@SqueakyNeb That makes sense I guess. Because yeah, it's hard to believe that any "name brand" would manage to stay in business very long if this is what they're giving customers lol. Buy hey, looks like he's making the most of it, so kudos to that.
@@hersch_tool Yes this video series started years ago, but the whole idea behind the project was to turn this pile of QC-reject parts into an actually usable lathe.
@@SqueakyNeb is exactly right. This machine was way cheaper than even the cheapest other new machines I could find. Some of the parts barely fit at all, and others seem to have mistakes made during assembly that are hard to correct.
A couple of tips on scraping: I don't use a roller to spread the blue, I just smear it on with a finger (latex gloves of coarse) - especially for small parts like these prism and dovetail surfaces. First pass is usually too thick but if you rub that off and go again you can usually get a good pattern. Second tip (and this one really makes it easier!): Buy a tube of red artists oil paint. Smear a bit on your workpiece before your do a check with the bluing. Just smear on a bit, then wipe it off with a paper towel until all that is left is just a reddish tinge, then do your pass over the bluing. Those hard-to-see blue spots will pop out in living color!
It should still work. The red color is just to add some contrast against the natural bluish-black color of the metal to make the high spots show up more clearly. Use artist oil paint because it doesn't dry. ....and you really shouldn't have to thin the marking blue either - just spread it real thin. I didn't know it was available in black....
@@tedhansen2830 Thanks mate, ohh you can make your own marking dye, just get some mineral oil and the finest pigment, in my case lamp black powder. Makes good stuff both for this kind of work and you can also mix your own wood paint with some linseed oil or use the pigment to color epoxy for example. You just need to remove mill scale from the metal before marking, personally I have not gotten to scraping yet, I "scrape" with the angle grinder then i lapp
I've never used an OIL based product for marking work for scraping, it seems to me it would be too thin. The industry norm is Prematex Prussian blue, which is GREASE colored with Prussian blue. It is so cheap and you use so little that it doesn't seem worthwhile to try to substitute. Amazon price is around $10 for a tube which would last for years doing small jobs like upgrading mini lathes. On other hand, I do mix my own layout dye. Brand name Dykem is stupidly expensive anywhere but the continental US because it is alcohol based so gets classed as dangerous goods for shipping.
Thanks Ted! I can remember watching a video on Suburban Tool's channel where I think the professional machine rebuilders used two different colours, I think one was yellow, so what you are describing totally machines sense. Since I did the work in this video, I have experimented with Prussian Blue oil paint, and found it pretty effective. I'll get hold of a tube of red and try out your technique.
G'day mate, I'm learning this process too, and one improvement I could suggest is that when you are bluing up the surfaces to scrape, use your indicator to map the top surface and bias your scraping to correct misalignment here. So if the back right corner is sitting low, then scrape more off the front left corner. Continue this effort until the piece is parallel to the bed, perpendicular to the prismatic ways (scraping the prismatic section unevenly will allow you to rotate the piece with respect to the work axis) and stable, then scrape down to an even contact surface. When you get to the saddle, remember the cutting forces will bend the saddle near the apron so it can rock. To counter this, get it perpendicular, parallel, stable and with even contact, then hollow out the middle 1/3 of the saddle prismatic section just a tiny fraction, so when the tool pressure pushes it down, it becomes flat in the middle and stays stable. Thanks for sharing your adventure and look forward to seeing the next video.
Thanks Owen, that's a useful guide. I've taken a copy of your description down, and kept it among my other scraping notes. I kinda avoided thinking much about geometry while I was working on these parts, and focused just on bearing. I'm aware that isn't really the right approach for the best overall results, as I could have made the geometry much worse, but it did keep things a lot simpler while I focused on learning the technique.
Thanks Michel! I wish I had more time for video making, but I have so much to do to get the house ready for winter. Congratulations on the new lathe! I'm really enjoying watching you work on it.
I tend to find every wrong way of doing something before finally discovering the best/correct way of doing it but then i know how and why its done the way it is. I also then like to show others the way it should be done and can explain to them why its done a certain way. Thanks for your efforts and time showing us .
As for your statement about a band saw, I used a portaband set in a vertical holder that mounts in vise, I mounted a small plate to act as a table to cut on
I have found that my lathe is made in a similar way and am looking forward to your project and finding away to correct it. I have used sharpie to blacken a surface and rubbing it to a mating surface rubs off the sharpie. Thanks for sharing.
You asked for tips so 😅 When you're inking the brayer, it seems like you're keeping it in contact with the glass and rolling it back and forth. When you do that, the same place on the roller sees the same thick and thin spots on the glass over and over. If you lift up the brayer between rolls, it should get to a thin even layer much more quickly. Really admire your willingness to go for it on this project! Thanks for posting it
You have inspired me to tackle my similar mini-lathe. The tail-stock has always seems terribly imprecise and unstable. I basically only use my lathe to turn bushings and modify bolts. Learning skills like scraping seems like a worthwhile investment though many in the comments seem to think that quicker results are necessarily better. Scraping seems like a basic skill that every machinist should be familiar with.
Gday, as far as I’m aware scraping is an art form and the only way to learn is to have a go, it’s enjoyable to learn new things mate, great job I say, cheers
I still have the scrapers made by my father in the 195o's and 60's which he used to scrape bearings and brake drums (dint ask the process but it did not involve a lathe and wont pass health and safety. These were made by grinding off the teeth bach to a smooth surface from old files. I have flat, tapered and half round taper. They hold their edge pretty well still.
Other youtuber's who show scraping technique seem to recommend a much thinner scraper bar that has more 'flex' in it. One simply made a Sandvik-style scraper using 4mm stock bar. It's a pleasure watching you work.
Great documentation of your learning adventure. Yes it is as simple as removing the high spots and checking. Keep in mind you can speed up the roughing phase by filing sanding honing and grinding, then go to finishing with the scraper. You have already made a huge improvement in the tailstock, the headstock will be less alien to you. Best of all, you have control over your equipment, and your understanding will pay off in the long run, cheers!
Honing or lapping should really be used to finish after the scraping has been done... I fully agree with filing, grinding and other stuff as a roughing method, but honing and lapping are instrument makers methods of mirror finish that can allow you to increase the width of the contact points derived from finished scraping... Kinda like Robin Renz showed his Moore micro pattern being ``lapped`` in with precision ground flat stones, which indeed can be considered a lapping plate to an extent... Its not a roughing method however... It removes microns, roughing requires quite a lot more than microns of removal per pass...
@@camillosteuss I need to go back and re-watch Robin's video. I always thought that honing after scraping was to be avoided, as the scraped pattern was valuable for holding an oil film.
@@AdventureswithaVerySmallLathe Yeah, it is, but in a way, it highly depends on the thing being worked... He did it with a machinist level, which doesnt really wear or slide as to require that much oil, but it can greatly benefit from an instrument grade surface... You just lap it in partially, not to iron out the scraping marks, but to turn the ``high points`` into flat peaks that more evenly sit on a surface and produce less pressure on contact points, which i guess does also do good for sliding surfaces, as the lower the pressure of the contact, the easier time the oil has in remaining between the two surfaces... As with scraping, its an art just as much as its a science... Tho, i always recommend rewatching Robin`s vids... They are a treasure trove...
This is fascinating and I’m certain my Vevor 7x14 would benefit from these techniques. I am curious, however, why wouldn’t this be easier, and possibly more accurate, if lapping compound was used instead of a scraper? It would seem to me lapping all the contact ponts simultaneously would result in a more uniform plane of contact? 🤷🏼♂️
A uniform plane of contact isn't actually desirable. A scraped surface with many contact points retains oil much better, and provides smooth sliding without sticktion. The other issue with lapping compound used between the bed and the tailstock is that it would lap the bed in preference to the tailstock, causing the bed to become non-straight. The grains in lapping compound get embedded in whichever material is slightly less hard, and abrade the harder material. The bed ways of a lathe are typically hardened, so they would end up being lapped, which would wear trough shapes into the bed where the lapping was done.
What would you lap it against? Not the bed, you'd be practically guaranteed to end up with a uneven bed, and potentially embed carborundum particles into the cast iron.
@@ferrumignis My thoughts exactly. It's difficult to explain the full background on why machine rebuilding has settled on hand-scraping as the best way to match sliding surfaces, as there is so much detail to go into.
My first scraper was a flat file, the ground as mentioned. First scraped a piece of aluminium and I'd recommend it to practice. Even with the alu my scraper went blunt quite fast. Now I bought a Sandvik tip, used for hours and remained sharp, separates visible amount of cast iron
Hello Alistair, An interesting video, thank you. I was wondering if you measure how parallel to the ways the top surface of the piece you scraped was. Take care. Paul,,
Hi Paul, thanks for watching. At this stage I didn't pay any attention at all to geometry, just fit between the contact surfaces and the bed. I know there will be a number of geometry corrections to make if this lathe turns out to be worth it, but I don't think it'll be clear until I fix the fundamentals.
Great video, thanks for sharing. I also had issues with my mini lathe tailstock, which I largely solved by re-making the base. I used your logic, in that if it went horribly wrong, I still had the old base (which would have still been better that none!). Indeed, I STILL have the old base! My replacement has served me well, but I can't drop the old one in the scrap bin -I might need a bit of cast iron at some point 👍 🇬🇧
Thanks! It is tempting to remake the tailstock base, but I think I may be better off buying a replacement for the whole assembly as the other parts aren't great either. If I can get the existing tailstock to line up, it'll be a great achievement and learning experience even if it turns out to be useless. Thanks for dropping by. I love your videos and have been a subscriber for a while!
6 months late, and I don't know if it's been said before. But part of the reason your first scraper didn't cut well and needed constant resharpening might be due to the grinding of the edge and the heat generated by the grinding. I've had hardened steel parts lose their hardening because they got too hot at the tip and effectively tempered themselves. Just something to keep in mind for the next time!
I commend you for putting so much time and effort into this lathe. Going to be an expensive mini lathe after you calculate in the hours😮 Then again learning new skills is also very valuable. You might want to check if the top and bottom of the casting are in the same plane, its easy to mess up the planes. Measure, measure and measure. Also try and get that cross hatch pattern.
If you intend to shim the headstock, it might be worth beaing in mind that it doesn't need to slide. Hence it only needs to be solidly bedded and to be aligned with the tailstock. Also, learning from your experience with clamping the shims to the tailstock, you might consider placing the headstock/epoxy/shim package on the ways and using the weight of the headstock to provide the clamping force while the epoxy cures. Or not using epoxy at all..
Thanks for the suggestions. As I've hinted in other comments, I've already done the work on the headstock, but didn't include it in this video as the length was getting too long. Editing it all into a single video that makes sense got too daunting. Hopefully it won't take too long for the next video to be ready, and you won't be disappointed by the approach I took.
I am about to tackle the same problem on my big lathe's tailstock, on which I'm just finishing a major refurbishment, but in my case the remaining height discrepancy between prism and flat way is a tiny fraction of yours. In my case it's remaining after my machining both surfaces to correct the alignment of the barrel bore with the turning axis, and honing the bore -- both of which were spectacularly successful. (I had to build a rigid hone for the purpose, very accurately guided) The Schlesinger toolroom lathe (toughest grade) limit for parallelism (10b) is 0.01mm in 100mm in the horizontal plane (twice that in the vertical), which it was far outside: I've managed to get it down to 0.002mm. I've given a bit of thought to how best to proceed with my height mismatch (a separate issue) -- I've pretty much decided I need to teach myself how to scrape properly -- but I'll ponder yours and see if I can offer anything worthwhile.
That sounds like quite an achievement, and has reminded me of the daunting task ahead before this tailstock is usable. As I've already mentioned the overall quality is very low, so I may as well go all out and try and fix as many of the alignment issues as possible. I don't think I have any hope of getting as good as 0.01mm with any reliability, I can at least learn from the process.
Lovely to see a video from you drop. If you haven't come across it: The channel "An Engineer's Findings" has a video called "Hand scraping carbon steel: carbide insert geometry" about the difficulties of scraping mild steel vs the usual cast iron used in tools. As I understand it "Turcite" is the material of choice for resurfacing ways, but I imagine mild steel is a lot easier to come by and cheaper for experimenting on. (I'm sure you're aware of Keith Rucker's rebuild of his machine with it). These minelathes seem ideal to see how far you can take it using whatever methods are convenient at hand.
I have come across An Engineer's Findings videos when I was checking on my video resources to add them to the description here, and watched it with great interest. I do think the problem he solves is a bit different, as he's working with quality carbon steel, whereas I'm just dealing with cheap mild steel plate.
So just listening to your learning process, I think you have a great method for learning new skills. I'm not a machinist. I just watch a lot of youtube videos and am fixing up an old Atlas lathe. So I really don't have much experience, but I think the right fix for this mismatch is to machine the lathe bed. If you could just machine that forward 45 deg angle on the bed, both the tail stock and head stock would set lower, bringing the back flat section into line. It would also move both of them back, get a larger surface area for all contact areas, and it looks like the contact should be moved farther back so there is a larger surface on the flat part of the ways also.
Unfortunately this approach isn't an option. I don't have access to tools anywhere near big enough to machine something this size, and it would need to be done with great precision to avoid messing up the lathe's geometry.
I am no machinist of any kind I was thinking you could tape emery paper to the bed of the lathe and sand the edges flat it would take off the high spots. Cheers
HI Well Done. I hand scraped the bed of an Atlas Press Company lathe into alignment with a surface plate using much the same methods you are learning to use. The lathe then gave many years of good use where the saddle could not be adjusted at the head stock end without freezing tight at the tail stock end before i did the scraping.
Had to scrape mine in the same way. I actually shaped a regular file and used it to scrape with. Amazing how bad off these are. but its like they say, they are truly a kit.
For the last finish you could use valve grinding paste, the high spots would grind down first and should make for a nice contact with the bed. But it may be difficult to keep it consistent on the whole length and not make the rail uneven...
I think it would be very hard to make sure they geometry of the prismatic way didn't get ground crooked. My understanding is that when lapping, the free abrasive tends to embed into the softer material, and have more of an abrahsive effect on the harder material. As I'm pretty sure the tailstock base is less hard than the ways, it would be the ways that got ground by the paste which would be very difficult to keep even.
First of all, i have to say that all my "knowledge" on scraping also comes from RUclips videos. However i have two remarks. To me it looked like you always scraped in one direction. Typically i see people make two passes at 90 degrees from another. This should help to break up the contact pattern. The second point is the scraper geometry, I remember a video by " An engineers findings" about scraping steel. I think he added a heel to the scraper improved the performance in steel a lot
Thanks for the suggestions! At some points in this process I did try two passes at 90 degress, but the other problems I had distracted me, especially the very small contact faces I was dealing with. I have just finished watching the "An engineers findings" video, and it's a great resource with an incredible amount of rigour! It does illustrate that scraping steel is much more difficult than cast iron, which reinforces that cast iron would have been a better choice for this project.
Yes please, make the video about adapting your grinder for carbide i think that's interesting and would be very helpfull, i already have the carbide paint scrapers in my shopping cart to make some test also and learn to scrape since i'm making the tapered gibs carriage mod. Thanks for the tips very appreciated :)
I admire your persistence. But sometimes it feels like going into a rabbit hole. I've been there myself endless times. My new approach for similar cases is: machine the part that is broken or bad, from scratch if needs be, and make it fit perfectly and also look cute, not like Frankenstein. My cross slide (cast iron) dovetail broke off on the first day, and I was forced to machine a replacement from cast steel, and it was my 1st project ever. I also machined the lead screw holder from larger solid cast steel, a d drilled the hole with 10mm end mill, to have almost zero backlash. I enjoy your struggles ;)
Excellent narration,I enjoyed the video.I like how you used glass,instead of a surface plate. I think Dave Gingery mentions that in one of his books for people who dont have a surface plate,I plan on scraping this old Southbend lathe I have, but going to wait untill I have the proper tools.I thought that was neat how you used a paint scraper carbide and customized it to your hand scraper.
Quick question - would it not have been easier to mill out one edge of the prism groove in the tailstock, shifted by say 15 thou, but at the same angle as the original and no deeper. This would give you a slightly wider prism groove, with identical wall angles, but retaining the same depth of material above. The groove would sit deeper on the guide prism, with more even contact and you might not need to shim (and scrape the shims :[ )
I was thinking the same as Alistair was discussing making the groove deeper. Seems that it is deep enough, just not wide enough. Then the bearing sides would want to be scraped to true things up. Quite a task he has set for himself.
Great idea, the unintended consequence however would be the whole tailstock height centre position in relation to headstock Centreline would change. I realise for what was being done in this video that wouldn't have mattered as it sounds like it is scrap and just a practice part. Just wanted to add this in case anyone went down this route. Good thought process though👍
Thank you, @@jonsworkshop. But to keep the conversation going, doesn't the installation of the shims de-center the tailstock anyways? You are rotating it about the axis of the prism guide, so you are essentially introducing sine error. Seeing as our Host will have to realign the center anyways... I'm just wondering, because I have a lathe that's very similar, and I'm going to be realigning and tramming the tailstock soon.
@@misterbreakit2006 hi, on any normal lathe I have ever seen and used I totally agree with you. This horrendous excuse for a machine however is different by way of missing material on the flat side of the bed. It is probably possible that taking up that gap whilst not messing too much with the vee side would fix the rigidity whilst keeping the tailstock on centre. All of that assumes of course that the tailstock centre height was correct to the vee side in the first place, which noting the missing material on the flat side is highly unlikely. I don't know how people can sell stuff like this with a straight face, absolutely shocking. Your reply is correct though, any level of scraping on a tailstock will alter the centre height. Cheers, Jon
That's a really good point, and I think I got trapped into thinking I needed to make the prism groove at least somewhat deeper if I wanted it to be wider. Thanks for all the followup comments @jrkorman, @jonsworkshop. I knew that whichever approach I took the tailstock alignment would be changed, but as I knew it didn't align correctly in the first place this wasn't a problem. As I've commented elsewhere, I was inclined to go in the direction I did because it was a reversible decision. If the shims hadn't worked out I could have removed them and tried the other approach instead.
I used reversed sandpaper on the bed groove, then moved the tail stock base plate and head over it to lower it end fit the groove. Parts are soft metal.
I had the same problem and solved it by making my own base for the tailstock. I have not finalized the machining of the shoulders as I have to do something similar for the headstock. and of course the saddle will require something similar. The only thing that will not change is the bed.
I love your attention to detail and almost phorensic examination of parts, etc. Given the Proxxon 250, CJ0618 and Unimat 3 - if you could only have one of them - taking into consideration; precision, handling and overall satisfaction of use - which one would it be?
As kokodin5895 says, remachining the V groove will solve all the problems. I have a similar lathe with the same problems, they all have as far as I can see. The V groove is 92 degrees so an end cutter on the mill will fit right to the top of the V without touching tho opposite side, I made a 44 degree wedge support to set the part at the right angle for machining. The tailstock was done first, I needed to widen the V groove by 1.4mm so I took 1mm off the side nearest the center of the lathe bed and 0.4mm off the outer face, it fitted fine with no discernable rock but lowered the tailstock by about 1.5mm so the top part had to be shimmed to get it back on center. A month or so later I tackled the saddle and headstock in the same afternoon, much the same set up but far harder to hold and very light cuts had to be taken. I cut the same 1mm from the far edge and 0.4mm form the front hoping that they would all line up as before when refitted. They fitted well but the down side was that the front saddle gib was now bottoming out on its screws so the gib seat had to be skimmed a suitable amount. Another downside was a visible crack inside the rear of the headstock, it only went part way through the casting but made me very careful when tightening the screws during refitting. Also the screw holes for the apron had to be drifted 1mm or so towards the front to stop the half nuts bending the lead screw when engaged as the saddle now sits a little rearwards of its previous position, it was lower as well but the leadscrew bearings had enough adjustment to allow for this. I still needed thin shims between the tailstock and its base to get the height right but I expected that. The outcome was all 3 items are now sitting square on the bed with no rock, machining is now much more positive with less vibration and squealing, all I have to do now is improve the awful gibs in the cross slide and compound as they are just not solid enough, even when locked with the gib locks I added at the same time as I cut the Vs. I would say that as a rule its best to fix the problem rather than try to get round it, I considered shims at first but decided to go "the engineer's route" and machine everything to fit, after all it only has to be done once. My lathe came from Vevor and I complained about the fit of the tailstock, they offered me a £20 refund, I pointed out that this would not fix it and they upped it to £40, I looked at their website and pointed out that a replacement tailstock was £121 and accepted a refund for that amount. As it happens a new one would not help as they looked axectly the same, it might have been some work with a steep learning curve, I am a relative newcomer to machining, but the problem is solved and I am £121 better off. Your videos are very instructive and entertaining and I have watched them all, how about a sub series Adventures With A Very Small Mill as your's is definitely in that category. Keep posting the videos.
I don't know why but I thought you had done this 3~4 years ago? For cast iron, an old vented brake disc should be more than enough to cut 'sheets' to shim headstock? (I'm sure you will find a use for the surplus) Although if you wanted thicker, a solid disc will probably be around 10mm thick.
This video is of work I did a while back, and I posted a couple of still images at the time. The video was on hold due to family reasons, and then while I moved house. I wanted to wait until I had time to finish up the details, and do a decent job of the editing. I hope it was worth the wait.
On my little import lathe the headstock was misaligned with the bed by about .006" over 13" toward the operator and .010 vertically away from the bed. I scraped it in to get the horizontal error easily corrected by torturing a few inch pounds more on the screws on the V and shimmed the rear of the V and flat with shim stock. Once I could easily repeat perfect alignment by removing the headstock and replacing it several times, I waxed the bed and screws then put a layer of jb weld onto the bottom of the casting, put the headstock back on the bed, tightened everything down back into alignment, cleaned up the excess squeeze out and waited 24 hours for the epoxy to cure. (Same as bedding a rifle stock) The headstock now has 100% contact to the bed and is aligned to the bed to within .0003" both horizontal and vertically. Alignment was done with an mt3 test bar and 4" machinist level.
Great video! I have learned so much watching you work on this import lathe. I have one also and I'm experiencing many of the problem you have shown. Your vids have helped me to know what to check and how to go about fixing the problems with this lathe. Thank you so much.
It's going to affect it a lot, but fortunately the tailstock was already badly out of alignment, so nothing serious lost. I'll have to rebuild the rest of the tailstock and fix the alignment in a future video.
Always scrape next pass crosshatch to previous, it will give you a better surface. If you need to peel off more material use just double passes with crosshatching directions. Use red oil based paint it's more contrast on metal.
Keith Rucker at Vintage Machinery is one of the best sources on scraping on RUclips. Search him up and you will find many videos. Just watching this, I suggest cross hatching the scrapes. Scrape at an angle and then go back with the opposite angle to make Xs. Good work on your first attempt!
Keith has been an inspiration and a source of knowledge since my earliest days with machining on RUclips, but when I was digging up resources for this video I had trouble finding the most useful videos in his enormous backcatalogue. If you have any particular videos of Keith's you think are most worth learning from, please drop me a link via email (in the channel About tab). (Unfortunately RUclips deletes comments containing links).
I always use Paragon Paints for small machine painting. They are good quality, and they have matched colours for the original manufacturers tone. I'm not sure how widely available they are, but worth a try.
@@AdventureswithaVerySmallLathe I don't know the brands you mentioned. In fact, I don't even have the means to reach them. I'm curious about what alternatives there could be instead of these brands. For example, what type of paint is it, acrylic or oil? In other words, is it a product that is much more affordable and easily accessible? I'm looking for a solution though. :)
Are you talking about paint for the outside of the machine, or the blue marking compound used for scraping? If you mean the blue compound, then it's generic name is "micrometer blue" or sometimes "engineers blue". The most common product is "Dykem Hi-Spot", and in the UK there is "Stuarts Micrometer Engineers Blue". Do not confuse this with layout fluid which is the same colour, but rapidly dries after being appliesld. You can probably find recipes for home made versions, generally using a dye called "Prussian blue" mixed with a grease.
Two thing's:- (1)As far as cutting or scraping a metal piece of any type of metal goes make sure that the metal of your hand tool/any drill bit is of a harder rigid material than your subject/workpiece. In this detail, carbide work tools, blades, and drill bits are the most preferable and the most bang for your money as they last a long time, and the fewer times you need to make any adjustment to your tools and drill bits the better. But there are times when your workpiece metal/materials are too soft for your carbide tools so, in that case, you have to work with a tool that has a tier higher hardness than your work metal or closest to it for example:- workpiece metal hardness is tier3/4 than your working tool metal hardness needs to be tier4/5 and so on. If I am correct the carbide tools hardness typically is between tier7-10 so you will be good to go on most projects. (2)Widening the groove in the x-axis and make sure it's all the way through the whole length of the groove in the y-axis while leaving the depth in the z-axis the same as you could have used your blue ink you have applied it on the face of the groove & sliding place piece while having them aligned with each other and having them clamped in the right spot and getting an ink impression on a thick paper or cardboard you could have figured out how much you need to mill the width of the V-groove equally on both sides overall and get the exact milling of the metal from the workpiece just right. The way you did it is for when your V-groove is flush with the track but your opposite quanter support section has too much play in the Z-axis and needs extra material to support it so it can be leveled with your track to speak off.
I understand why you couldn't deepen the groove, but was there a reason you couldn't widen it, giving it more space to sit further down on the prism way without removing the strength of the part?
That’s exactly the thought I had. The main reason I can think of to not do that is it looks like there isn’t enough material to operator side of the lathe, so essentially all of the material would have to be removed from the inboard side, which would cause the block to move towards the operator. This could be enough movement that the tailstock is no longer able to properly center with the headstock, making the whole repair pointless. Unfortunately it just seems to be an extremely poor casting. Too bad these manufacturers aren’t willing to spend an extra $1 to have the castings be slightly larger which would allow buyers to properly mate parts.
The hard part is getting the center of the tailstock to align with the axis of the spindle in the headstock, while at the same time being parallel with it.
I've thought about how I'm going to approach that quite a lot, and still haven't settled on an approach I'm confident will work. It'll be another great learning experience.
Hi! . There was one guy from UK that made a PPT how he made "epoxy way shims" making a composite out of bronze + graphite + ptfe powders and epoxy making in tokind of "boots" for each sliding surface.
I have a question. Wouldn't it be faster, and perhaps with a better result, to use fine sandpaper? Place the paper on the bed of the lathe, fix it with clamps. Attach the tailstock and move it slightly and let it grind?
I was apprenticed as a machine tool fitter and was lucky enough to have worked on all manner of machine tools. The best by far were British and German. Makes like Herbert, Asquith, Wickman, Jones & Shipman, So-and-so etc etc. Having seen these Chinese made lathes and milling machines and tried to use them, I am appalled at the quality. It makes me sad that nearly all of our machine tool industry has gone and people buy this rubbish. All of the old engineering colleges have gone that used to have good makes of lathes like Colchester, Harrison and so on. These old makes are still around as in used condition, but after 50 years or so are still far more accurate than the rubbish made in China today. Colchester lathes had a motto on all their machines which read "the world turns on Colchester lathes".
For a cast iron, you need negative rake, and you controll depth of the cut by downward pressure on the scraper. And rake angle is important, depending on the type of the iron. 5 to max 8 degrees. Thin the blade so you can reach tight spots. Its just angle on the edge that counts. blade itself can be tappered or whatewer. For a mild steel, you need to grind positive rake, but also need to grind a "heel" (like on engraving tools), and you control depth of cut by changing the angle. Steel can be scraped very nice that way. Check An Engineer's Findings clip about it. For polishing the edge.. just make block of some realy hard wood like locust, hornbeam or similar, with 95 degree angle. Notch that edge for about 1-2mm. Flat brass stock and diamond paste... Put the insert on one edge of wood block, brass stock on another and you will get a guide for your 5 degree rake. Remember.. carbide do not like to be grind or honed away from the edge. It is so hard that it will microchip the edge. Change dirrection of scraping for 90 degrees on every pass, so you avoid chatter.
Findings of an Engineer has some tips on scraping steel. The negative rake is for cast iron because it's brittle. Positive rake for steel but grind a heel so you don't dig in too far. Scrape for bearing on the tail stock, like the other guy said. A HSS scraper should last for several passes on such a tiny area.
Thanks for the tip! I'm hoping I can sort out a vertical bandsaw that makes cutting sheet steel like this easy, and I think I've heard Starrett bandsaw blades are worth the money too!
When using a hacksaw, it is best to make long, fast strokes. And positioning yourself so your arm naturally moves in a straight line can improve the cut too. You will be amazed how fast and clean your cuts are after a little experimentation. Manual hand tools are extremely powerful and make less mess when proper technique is used.
excellent work on this. your mistakes really add character to your machine and great content to your video. Keep it up, looking forward to the headstock
Your thought process and attack philosophy is sound other than choosing mild steel for the shim pads. The JB Weld raised your pads and caused more scraping than necessary. At least the contact area increased. Now is it parallel to the ways? Clamp the tail stock base to the Ways to check for parallelism. The Headstock will be very hard to resolve. IYour approach with the Tailstock with shims and a skim coat of JB Weld and scraping to creep up on a proper fit might be your best method.
A few things... Go in alternating directions when scraping... You cant just approach the material from one side, you have to cross your scraping marks, kinda like how you sand stuff, you do it from one direction and the next pass is from another angle across the prior one... It prevents you from making furrows or grooves in the surface, and results in points, rather than streaks of contact... You are getting nowhere apparently most likely as a result of working on that exact combination of V+flat ways, as any level of angular change or change in fit in the V groove instantly tweaks the flat way contact... Scraping is an art, and reading and understanding the printing and relying on other checking methods is quite tricky, as you have to know what influences what, and how stuff will interact with ways in perfect situation, and how any deviation from perfect fit will change the picture that the printing shows... I would most definitely try and mill out the V groove a bit before the job, its not so flimsy as to be unable to be milled down 40thou or 1mm... That would have deepened the contact area, and could have allowed you to fix the fit of that section tremendously, allowing you to merely focus on scraping of the flat sections until you get a perfect fit on that side... Also, for a proper intro to scraping, go to Gtsw Stefan`s channel and watch his work, and go to Robin Renzetti`s channel and watch his work in that area... They are invaluable as a source if you want to start scraping and between them, you will get enough tips and directions that if you ever have any questions, it will be the result of forgetting what they said and will return you to rewatch their videos as i have multiple times... All the best! Steuss
Thanks for the detailed explanation! I think that's help me understand the need for alternating directions better than I did before. Stefan and Robin are already in the list of videos I've viewed, though I definitely understand their videos much better now I've had my first try than I did before. Congratulations on setting up your new RUclips channel, you have a new subscriber!
@@AdventureswithaVerySmallLathe Ayy, thanks, and anytime... Glad that you are interested! I will be posting a ton of machine related content as time goes on, but at the moment, things are more than just a bit chaotic, to put it mildly, so things take even more time than i would usually be okay with... I see that you have been posting for a relatively long time now... Yet i just found you today... Strange how you get to find channels that have a long history on the topic you have been following for over a decade, without ever seeing them before... Sometimes all i get for weeks in my home page is stuff that i have rewatched at least 3 times by now, and there are dozens of channels that do things similar or related, yet you have to somehow dig them out yourself before youtube will ever show them to you... All the best and kind regards! Steuss
I'm sure it's already been mentioned but... Grinding the groove doesn't involve grinding it deeper. You just have to grind it wider. You could grind all of it off of the outside edge so the flat would move over the way more also.
For some reason I have a sweet spot for “improving sub standard mechanical devices”. Your video editing, voice over, approach to the task at hand…in the top tier in my opinion. 👍 About the bench grinder, I would love to see how you made the diamond wheel adapter as well as your approach to some upgraded grinding rests. No pressure 😊 Thanks once more for great content.
Thanks, I'll add that to the video list, though I can't promise when it'll come out. I'll probably go for a lighter-weight video than usual, without quite so much detail.
Not going to claim I'm an expert on this or anything. But I think there's a problem with your procedure on this one. Basically, as you scrape away material on the shims you're rotating the casting about the angled ways like a fulcrum. So until you're getting flat contact on the shims, the contact points on the other two surface would be changing as you're scraping the shims. As well, you're also essentially moving the fulcrum at the same time by scraping all three points, so you'd have to move relatively more material from the shim to see any difference. To me it would make the most sense to only scrape the shims until you were getting pretty even contact along it's length, and then start scraping all 3 surfaces to bring it down evenly.
My thought process was that by removing material from all three surfaces at the same time, I was keeping the rotation around the fulcrum to a minimum. From the first print I took I knew the back of the base was still tiny bit too low, so I didn't want to make it any lower, so I wanted to make sure I kept taking material off the prism groove to keep lowering the front at roughly the same rate as the back.
@@AdventureswithaVerySmallLathe ah, understandable. It seemed like in the video, with the high spot being towards the back of the shims, that the rear end was up higher. If the top was level though then of course you'd want to keep that. Either way, I'd suggest reading "Machine Tool Reconditioning" by Edward Connelly if you haven't. It's got a lot of great info that takes everything into account.
I'm wondering why you didn't establish your high points before you started scraping? The idea with scraping is that you only scrape the high contact points. The areas that rub first. And expand as the contact point becomes more even. Personally, if I was ready to make pads for the machine, I'd hog out a spot to install a larger piece of metal right across then machine it down and even. Use Emory on glass to flatten it, then check the contact pattern and scrape from there. Hard to say what the best method is given how much slip there is in your machines
Nice work! Im going through the same modifcation. How will you align the the headstock to the tailstock? Are you planing to mod the tailstock for adjustment? You could use self lubricating bearing brass for the sadle shims.
why machining the groove wasn't an option? if i am not mistaken, unless the groove already touches the bottom, your ilustration would be correct, othervise you could simply remove some materials from the sides of the groove and it would fall deeper as e resoult untill it would actually touch the top of the rail, although it could also move side to side, it could have aded bonus of increasing the area of contact
Whenever I make a decision about working on this lathe, I'm biased towards any approach where I can most easily change my mind later. If this way had not worked out, I could have machined away the shims and tried the approach of machining the groove instead. They approach I tried ended up working out, and it didn't take away any options in future. If I had machined the groove first, and screwed it up, I wouldn't have any other option to try.
Note that widening the V-grove of the slide would lower the tailstock requiring shimming the top of the slide, so two steps instead of one.
@@DJW1959Aus yes but can it really be aligned as is after shiming the base , i mean if it was aligned while being crucked on a wierd angle as it was, you will have to deal with it anyway, so it highly depend on how the tailstok was aligned before if it was at all. if it was then after shiming the base you may even have to mill it down. there is a lot of variables to work with when you are dealing with a column mounted on 2 pivit points and you modyfy even one of them
@@AdventureswithaVerySmallLathe fair point, it all depends on avalable setup options to machine it, i was just a bit at ods with the explanation in video. whatever works for you , still that plate looks like it is a bit small , was it the oryginal part of this lathe or there is no info about where it came from?
There is an issue that must be considered and that is the final distance between the bed and the center of the complete tail stock. It should be exactly 7 inches in this case. Actually, you should measure the height of the center of the headstock bore above the bed and then set the tailstock to that exact value. So if you get the base plate a bit too low you can always use large shims that cover most of the contact patch between the parts in the tailstock to bring it to that height.
I'm trying to learn to use metal working machines, too. I love having access to people with decades of experience and people as new to these tools as me.
When folks like you demonstrate what you're trying, and include all your discoveries, mistakes, and successes it is a huge boon. Being able to observe mistakes I would have also certainly have made, processes I never would have thought of, or even things I know are wrong - it builds my skills and my confidence.
If comments by other content creators are anything to go by, youtube can bring a lot of negative feedback. So, for what it's worth, I appreciate you and others who are willing to record, edit, and post content (a significant effort in itself) and put yourselves out there with what you've tried, wherever you are on your learning curves. Thanks!
Thanks for the feedback. Your confirmation makes it easier for me to include all the mistakes and inexperience, which can make working on these videos really nerve wracking.
A very fine comment.
You learned an important lesson that every machinist should know though: The more blue you put, the better the parts fit ;)
Oh yeah! The first print I did, nothing but solid blue across the whole area. Perfect fit, as the thumbnail says!
With the caveat that I've never personally done any scraping - in the scraping videos I've watched (who would have thought my life would come to this?) they've always employed a cross-scraping pattern, whereas you appeared to be going at it from one direction only. A second pass at 90° to the first removes more material, and helps even-out the scraping marks, speeding things up and leading to a flatter surface. Keith Rucker is a master at this stuff.
This was what I wanted to comment, as well.
Also, like you already found out, cast iron is perfect for scraping.
Thanks Barty and Dan, this is a really good point. I did start off trying to scrape in alternating cross pattern, but the small area I was dealing with, and the other challenges I was facing distracted me, and I lost focus on making sure I did that.
Working on the prism groove, the width of the area to be scraped was so small it was difficult to scrape at an angle at all.
Firstly, just make your own carbide tool by brazing a piece of carbide to anything. I prefer old pry bars. I've also never ground a piece of carbide in my life because of this. There are enough broken lathe bits or end mills that will be radiused if you need it. The radius make sense when your learning I guess but I can use a straight edge just like a radiused one. The negative rake is really the only necessity and that can be eyeballed. You are "theoretically" only supposed to be touching a single point of material anyway with the radius and all.
Having done a bunch of scraping the hashed appearance is just that. Appearance. People can argue all they won't about how much oil it holds, cool, whatever you want to do in your spare time is fine. What the 90 pattern does stop you from doing is creating a bias that you can find yourself overlooking from only one side of the scraping tool.
Ultimately you are looking for 40 touch points per square inch (minimum and maximum there does need a place for oil to be and you aren't looking to wring these surfaces together), since an inch by and inch is easiest to measure from one side to the other shooting up-down then diagonally is a very logical way to proceed. When I have done larger faces, I would start one direction then beyond move 15 degrees past 180 each time so as to not have a big hump or otherwise. When removing material I imagine myself, "printing" or rubbing the average value I am looking onto the surface where I want it. I am trying to to remove material to allow the not yet colored surface to slowly come up while trying that to preserve as much of that blue contact area as possible.
Another source for surface plates are granite countertops. Those commercial companies spend a lot of money on those diamond bits to ensure those things are pretty flat. Maybe not truly parallel but flat for the size you are touching off. If you plan on doing any amount of scraping, once you get the bug you will start by scraping every tool you own then start considering scraping the disks on your brakes, if you go past this tool just get a cheap little machine shop surface place for $100 shipped. That way you know you are getting something that was toleranced. Everything else is just not going to be a toleranced surface plate, just like your carbide.
Regardless, anyone will be hard pressed to find -anything-, I mean ANY TECHNIQUE that will give you a flatter surface than hand scraping. It's so worth picking up the skill if you have machinery of any kind. You will learn more in an hour with a carbide paint scraper or even a carbide endmill in your hand than you will a dozen hours of video. It's super simple to learn by doing and unbelievably valuable.
@@AdventureswithaVerySmallLathe You´ve done your part but may i suggest another method that i´ll try when my lathe comes in two weeks:
Superglue sandpaper on the rails and go over it with the slide. Begin rough to go fine later on. That should work well as many guys told in the comment section under even more videos. Seems logical to me. I´ll fix the lathe absolutely leveled with a fine machinists bubble level. Then start the process. This way it should possible to see if the slide is squared all around. What do you [guys] think?
@@kevinmullner4280I really hope you didn’t do this. It is a terrible idea. Sorry.
Thanks for bringing us along for the ride, sharing the good and the bad. Content producers like you infuse the rest of us with much needed knowledge without each of us having to learn the hard way.
Very much in agreement with going with the carbide scraper. I use carbide paint scraper blades too and for small hobby stuff like this, they are more than good enough. For a first go at it I think you did a great job.
Thanks! I honestly thought I'd get a lot of comments about using inferior carbide blades, but they seem to work fine to me, and the narrow width feels easier when working on small mini-lathe parts.
Your mini lathe mod videos were a great source of background and inspiration, so I'm really glad you enjoy my videos too.
The carbide paint scraper route is a very good idea. I myself, being old and cheap love such things.
Holy smokes, I am shocked by how poorly that thing is manufactured. Good on you for getting after it. Great video, and excellent work!
As I recall, this one was specifically bought as being unusually cheap and not from a decent re-seller (I forget whether it was in videos or in comments, but I think it was even speculated that this was specifically QC-reject parts assembled into a complete product). I recently bought a similar unit from a local reseller that sources them from a brand that *actually* does QC and it's NOTHING like this.
@@SqueakyNeb ...more commonly known as Franken-machines.
@@SqueakyNeb That makes sense I guess. Because yeah, it's hard to believe that any "name brand" would manage to stay in business very long if this is what they're giving customers lol. Buy hey, looks like he's making the most of it, so kudos to that.
@@hersch_tool Yes this video series started years ago, but the whole idea behind the project was to turn this pile of QC-reject parts into an actually usable lathe.
@@SqueakyNeb is exactly right. This machine was way cheaper than even the cheapest other new machines I could find. Some of the parts barely fit at all, and others seem to have mistakes made during assembly that are hard to correct.
A couple of tips on scraping: I don't use a roller to spread the blue, I just smear it on with a finger (latex gloves of coarse) - especially for small parts like these prism and dovetail surfaces. First pass is usually too thick but if you rub that off and go again you can usually get a good pattern.
Second tip (and this one really makes it easier!): Buy a tube of red artists oil paint. Smear a bit on your workpiece before your do a check with the bluing. Just smear on a bit, then wipe it off with a paper towel until all that is left is just a reddish tinge, then do your pass over the bluing. Those hard-to-see blue spots will pop out in living color!
Sorry to bother, I use black instead of blue to mark my work, is there a similar option for me?
It should still work. The red color is just to add some contrast against the natural bluish-black color of the metal to make the high spots show up more clearly.
Use artist oil paint because it doesn't dry.
....and you really shouldn't have to thin the marking blue either - just spread it real thin.
I didn't know it was available in black....
@@tedhansen2830 Thanks mate, ohh you can make your own marking dye, just get some mineral oil and the finest pigment, in my case lamp black powder. Makes good stuff both for this kind of work and you can also mix your own wood paint with some linseed oil or use the pigment to color epoxy for example.
You just need to remove mill scale from the metal before marking, personally I have not gotten to scraping yet, I "scrape" with the angle grinder then i lapp
I've never used an OIL based product for marking work for scraping, it seems to me it would be too thin. The industry norm is Prematex Prussian blue, which is GREASE colored with Prussian blue. It is so cheap and you use so little that it doesn't seem worthwhile to try to substitute. Amazon price is around $10 for a tube which would last for years doing small jobs like upgrading mini lathes.
On other hand, I do mix my own layout dye. Brand name Dykem is stupidly expensive anywhere but the continental US because it is alcohol based so gets classed as dangerous goods for shipping.
Thanks Ted! I can remember watching a video on Suburban Tool's channel where I think the professional machine rebuilders used two different colours, I think one was yellow, so what you are describing totally machines sense.
Since I did the work in this video, I have experimented with Prussian Blue oil paint, and found it pretty effective. I'll get hold of a tube of red and try out your technique.
Please don't delay in making other videos on RUclips. Your videos are a great inspiration for me. Thanks!
I promise, I never delay, I just have way too much to do, and hate to rush videos out before they're properly edited!
G'day mate, I'm learning this process too, and one improvement I could suggest is that when you are bluing up the surfaces to scrape, use your indicator to map the top surface and bias your scraping to correct misalignment here. So if the back right corner is sitting low, then scrape more off the front left corner. Continue this effort until the piece is parallel to the bed, perpendicular to the prismatic ways (scraping the prismatic section unevenly will allow you to rotate the piece with respect to the work axis) and stable, then scrape down to an even contact surface.
When you get to the saddle, remember the cutting forces will bend the saddle near the apron so it can rock. To counter this, get it perpendicular, parallel, stable and with even contact, then hollow out the middle 1/3 of the saddle prismatic section just a tiny fraction, so when the tool pressure pushes it down, it becomes flat in the middle and stays stable.
Thanks for sharing your adventure and look forward to seeing the next video.
This
Thanks Owen, that's a useful guide. I've taken a copy of your description down, and kept it among my other scraping notes. I kinda avoided thinking much about geometry while I was working on these parts, and focused just on bearing. I'm aware that isn't really the right approach for the best overall results, as I could have made the geometry much worse, but it did keep things a lot simpler while I focused on learning the technique.
Glad to see you back! So much fun to see how you tackle these projects.
Nice to see you posting again, Al. We missed you.
Some nice "pimp my lathe" in this one. A joy to watch.
Thanks Michel! I wish I had more time for video making, but I have so much to do to get the house ready for winter. Congratulations on the new lathe! I'm really enjoying watching you work on it.
I tend to find every wrong way of doing something before finally discovering the best/correct way of doing it but then i know how and why its done the way it is.
I also then like to show others the way it should be done and can explain to them why its done a certain way.
Thanks for your efforts and time showing us .
I found this really inspirational. I really liked to see exactly how difficult this process can be without all the mistakes cut out. Thanks!
As for your statement about a band saw, I used a portaband set in a vertical holder that mounts in vise, I mounted a small plate to act as
a table to cut on
Great to see a new video from you. Always enjoyed your mini lathe content
I have found that my lathe is made in a similar way and am looking forward to your project and finding away to correct it. I have used sharpie to blacken a surface and rubbing it to a mating surface rubs off the sharpie. Thanks for sharing.
You asked for tips so 😅
When you're inking the brayer, it seems like you're keeping it in contact with the glass and rolling it back and forth. When you do that, the same place on the roller sees the same thick and thin spots on the glass over and over. If you lift up the brayer between rolls, it should get to a thin even layer much more quickly.
Really admire your willingness to go for it on this project! Thanks for posting it
Thanks for the brayer tip, I'll give that a try!
And thanks for watching!
You have inspired me to tackle my similar mini-lathe. The tail-stock has always seems terribly imprecise and unstable. I basically only use my lathe to turn bushings and modify bolts. Learning skills like scraping seems like a worthwhile investment though many in the comments seem to think that quicker results are necessarily better. Scraping seems like a basic skill that every machinist should be familiar with.
Gday, as far as I’m aware scraping is an art form and the only way to learn is to have a go, it’s enjoyable to learn new things mate, great job I say, cheers
Thanks Matty, and great to see you drop by!
Hope things are going well!
I still have the scrapers made by my father in the 195o's and 60's which he used to scrape bearings and brake drums (dint ask the process but it did not involve a lathe and wont pass health and safety. These were made by grinding off the teeth bach to a smooth surface from old files. I have flat, tapered and half round taper. They hold their edge pretty well still.
Other youtuber's who show scraping technique seem to recommend a much thinner scraper bar that has more 'flex' in it. One simply made a Sandvik-style scraper using 4mm stock bar. It's a pleasure watching you work.
Great documentation of your learning adventure. Yes it is as simple as removing the high spots and checking. Keep in mind you can speed up the roughing phase by filing sanding honing and grinding, then go to finishing with the scraper. You have already made a huge improvement in the tailstock, the headstock will be less alien to you. Best of all, you have control over your equipment, and your understanding will pay off in the long run, cheers!
Honing or lapping should really be used to finish after the scraping has been done... I fully agree with filing, grinding and other stuff as a roughing method, but honing and lapping are instrument makers methods of mirror finish that can allow you to increase the width of the contact points derived from finished scraping... Kinda like Robin Renz showed his Moore micro pattern being ``lapped`` in with precision ground flat stones, which indeed can be considered a lapping plate to an extent... Its not a roughing method however... It removes microns, roughing requires quite a lot more than microns of removal per pass...
@@camillosteuss I need to go back and re-watch Robin's video. I always thought that honing after scraping was to be avoided, as the scraped pattern was valuable for holding an oil film.
@@AdventureswithaVerySmallLathe
Yeah, it is, but in a way, it highly depends on the thing being worked... He did it with a machinist level, which doesnt really wear or slide as to require that much oil, but it can greatly benefit from an instrument grade surface... You just lap it in partially, not to iron out the scraping marks, but to turn the ``high points`` into flat peaks that more evenly sit on a surface and produce less pressure on contact points, which i guess does also do good for sliding surfaces, as the lower the pressure of the contact, the easier time the oil has in remaining between the two surfaces...
As with scraping, its an art just as much as its a science...
Tho, i always recommend rewatching Robin`s vids... They are a treasure trove...
How would you go about honing the part in the video?
@@BigDaddyButthead90 I honestly have no idea. Honing and lapping isn't something I've studied much yet, so I'd be starting from scratch once again.
This is fascinating and I’m certain my Vevor 7x14 would benefit from these techniques. I am curious, however, why wouldn’t this be easier, and possibly more accurate, if lapping compound was used instead of a scraper? It would seem to me lapping all the contact ponts simultaneously would result in a more uniform plane of contact? 🤷🏼♂️
A uniform plane of contact isn't actually desirable. A scraped surface with many contact points retains oil much better, and provides smooth sliding without sticktion.
The other issue with lapping compound used between the bed and the tailstock is that it would lap the bed in preference to the tailstock, causing the bed to become non-straight.
The grains in lapping compound get embedded in whichever material is slightly less hard, and abrade the harder material. The bed ways of a lathe are typically hardened, so they would end up being lapped, which would wear trough shapes into the bed where the lapping was done.
What would you lap it against? Not the bed, you'd be practically guaranteed to end up with a uneven bed, and potentially embed carborundum particles into the cast iron.
@@ferrumignis My thoughts exactly. It's difficult to explain the full background on why machine rebuilding has settled on hand-scraping as the best way to match sliding surfaces, as there is so much detail to go into.
My first scraper was a flat file, the ground as mentioned. First scraped a piece of aluminium and I'd recommend it to practice. Even with the alu my scraper went blunt quite fast. Now I bought a Sandvik tip, used for hours and remained sharp, separates visible amount of cast iron
Hello Alistair,
An interesting video, thank you. I was wondering if you measure how parallel to the ways the top surface of the piece you scraped was.
Take care.
Paul,,
Hi Paul, thanks for watching.
At this stage I didn't pay any attention at all to geometry, just fit between the contact surfaces and the bed. I know there will be a number of geometry corrections to make if this lathe turns out to be worth it, but I don't think it'll be clear until I fix the fundamentals.
Great video, thanks for sharing.
I also had issues with my mini lathe tailstock, which I largely solved by re-making the base.
I used your logic, in that if it went horribly wrong, I still had the old base (which would have still been better that none!).
Indeed, I STILL have the old base!
My replacement has served me well, but I can't drop the old one in the scrap bin -I might need a bit of cast iron at some point 👍 🇬🇧
Thanks! It is tempting to remake the tailstock base, but I think I may be better off buying a replacement for the whole assembly as the other parts aren't great either. If I can get the existing tailstock to line up, it'll be a great achievement and learning experience even if it turns out to be useless.
Thanks for dropping by. I love your videos and have been a subscriber for a while!
6 months late, and I don't know if it's been said before. But part of the reason your first scraper didn't cut well and needed constant resharpening might be due to the grinding of the edge and the heat generated by the grinding. I've had hardened steel parts lose their hardening because they got too hot at the tip and effectively tempered themselves. Just something to keep in mind for the next time!
This is so good! Is so rare to see this part of the learning process with such polished and well presented video. im happy I stumbled across this
I commend you for putting so much time and effort into this lathe.
Going to be an expensive mini lathe after you calculate in the hours😮
Then again learning new skills is also very valuable.
You might want to check if the top and bottom of the casting are in the same plane, its easy to mess up the planes.
Measure, measure and measure.
Also try and get that cross hatch pattern.
That's a very good suggestion.
If you intend to shim the headstock, it might be worth beaing in mind that it doesn't need to slide. Hence it only needs to be solidly bedded and to be aligned with the tailstock. Also, learning from your experience with clamping the shims to the tailstock, you might consider placing the headstock/epoxy/shim package on the ways and using the weight of the headstock to provide the clamping force while the epoxy cures. Or not using epoxy at all..
Thanks for the suggestions. As I've hinted in other comments, I've already done the work on the headstock, but didn't include it in this video as the length was getting too long. Editing it all into a single video that makes sense got too daunting.
Hopefully it won't take too long for the next video to be ready, and you won't be disappointed by the approach I took.
I am about to tackle the same problem on my big lathe's tailstock, on which I'm just finishing a major refurbishment, but in my case the remaining height discrepancy between prism and flat way is a tiny fraction of yours. In my case it's remaining after my machining both surfaces to correct the alignment of the barrel bore with the turning axis, and honing the bore -- both of which were spectacularly successful. (I had to build a rigid hone for the purpose, very accurately guided)
The Schlesinger toolroom lathe (toughest grade) limit for parallelism (10b) is 0.01mm in 100mm in the horizontal plane (twice that in the vertical), which it was far outside: I've managed to get it down to 0.002mm.
I've given a bit of thought to how best to proceed with my height mismatch (a separate issue) -- I've pretty much decided I need to teach myself how to scrape properly -- but I'll ponder yours and see if I can offer anything worthwhile.
That sounds like quite an achievement, and has reminded me of the daunting task ahead before this tailstock is usable. As I've already mentioned the overall quality is very low, so I may as well go all out and try and fix as many of the alignment issues as possible. I don't think I have any hope of getting as good as 0.01mm with any reliability, I can at least learn from the process.
YES, I was waiting for this for months
Lovely to see a video from you drop. If you haven't come across it: The channel "An Engineer's Findings" has a video called "Hand scraping carbon steel: carbide insert geometry" about the difficulties of scraping mild steel vs the usual cast iron used in tools. As I understand it "Turcite" is the material of choice for resurfacing ways, but I imagine mild steel is a lot easier to come by and cheaper for experimenting on. (I'm sure you're aware of Keith Rucker's rebuild of his machine with it). These minelathes seem ideal to see how far you can take it using whatever methods are convenient at hand.
I have come across An Engineer's Findings videos when I was checking on my video resources to add them to the description here, and watched it with great interest. I do think the problem he solves is a bit different, as he's working with quality carbon steel, whereas I'm just dealing with cheap mild steel plate.
So just listening to your learning process, I think you have a great method for learning new skills.
I'm not a machinist. I just watch a lot of youtube videos and am fixing up an old Atlas lathe. So I really don't have much experience, but I think the right fix for this mismatch is to machine the lathe bed. If you could just machine that forward 45 deg angle on the bed, both the tail stock and head stock would set lower, bringing the back flat section into line. It would also move both of them back, get a larger surface area for all contact areas, and it looks like the contact should be moved farther back so there is a larger surface on the flat part of the ways also.
Unfortunately this approach isn't an option. I don't have access to tools anywhere near big enough to machine something this size, and it would need to be done with great precision to avoid messing up the lathe's geometry.
Oh man we all have to go through the process so you are doing great just keep at it you will get there
I am no machinist of any kind I was thinking you could tape emery paper to the bed of the lathe and sand the edges flat it would take off the high spots. Cheers
HI
Well Done.
I hand scraped the bed of an Atlas Press Company lathe into alignment with a surface plate using much the same methods you are learning to use.
The lathe then gave many years of good use where the saddle could not be adjusted at the head stock end without freezing tight at the tail stock end before i did the scraping.
Had to scrape mine in the same way. I actually shaped a regular file and used it to scrape with. Amazing how bad off these are. but its like they say, they are truly a kit.
My attempt to tailstock issue was to mill deeper v groove. Did the same to the carriage. Still more work to do, but promising.
thanks for sharing your journey and adventures
For the last finish you could use valve grinding paste, the high spots would grind down first and should make for a nice contact with the bed. But it may be difficult to keep it consistent on the whole length and not make the rail uneven...
I think it would be very hard to make sure they geometry of the prismatic way didn't get ground crooked. My understanding is that when lapping, the free abrasive tends to embed into the softer material, and have more of an abrahsive effect on the harder material. As I'm pretty sure the tailstock base is less hard than the ways, it would be the ways that got ground by the paste which would be very difficult to keep even.
First of all, i have to say that all my "knowledge" on scraping also comes from RUclips videos. However i have two remarks. To me it looked like you always scraped in one direction. Typically i see people make two passes at 90 degrees from another. This should help to break up the contact pattern. The second point is the scraper geometry, I remember a video by " An engineers findings" about scraping steel. I think he added a heel to the scraper improved the performance in steel a lot
Agreed, a crosshatch pattern is the basis of scraping next to measuring.
Thanks for the suggestions! At some points in this process I did try two passes at 90 degress, but the other problems I had distracted me, especially the very small contact faces I was dealing with.
I have just finished watching the "An engineers findings" video, and it's a great resource with an incredible amount of rigour! It does illustrate that scraping steel is much more difficult than cast iron, which reinforces that cast iron would have been a better choice for this project.
Great to see another video on the mini lathe. Have you ever watched any of Keith Ruckers videos on scraping.
Yes please, make the video about adapting your grinder for carbide i think that's interesting and would be very helpfull, i already have the carbide paint scrapers in my shopping cart to make some test also and learn to scrape since i'm making the tapered gibs carriage mod. Thanks for the tips very appreciated :)
I admire your persistence.
But sometimes it feels like going into a rabbit hole.
I've been there myself endless times.
My new approach for similar cases is: machine the part that is broken or bad, from scratch if needs be, and make it fit perfectly and also look cute, not like Frankenstein.
My cross slide (cast iron) dovetail broke off on the first day, and I was forced to machine a replacement from cast steel, and it was my 1st project ever. I also machined the lead screw holder from larger solid cast steel, a d drilled the hole with 10mm end mill, to have almost zero backlash.
I enjoy your struggles ;)
You are doing great, glad to see you are back.
Really enjoy and learn from your videos.
Excellent narration,I enjoyed the video.I like how you used glass,instead of a surface plate. I think Dave Gingery mentions that in one of his books for people who dont have a surface plate,I plan on scraping this old Southbend lathe I have, but going to wait untill I have the proper tools.I thought that was neat how you used a paint scraper carbide and customized it to your hand scraper.
Quick question - would it not have been easier to mill out one edge of the prism groove in the tailstock, shifted by say 15 thou, but at the same angle as the original and no deeper. This would give you a slightly wider prism groove, with identical wall angles, but retaining the same depth of material above. The groove would sit deeper on the guide prism, with more even contact and you might not need to shim (and scrape the shims :[ )
I was thinking the same as Alistair was discussing making the groove deeper. Seems that it is deep enough, just not wide enough. Then the bearing sides would want to be scraped to true things up. Quite a task he has set for himself.
Great idea, the unintended consequence however would be the whole tailstock height centre position in relation to headstock Centreline would change. I realise for what was being done in this video that wouldn't have mattered as it sounds like it is scrap and just a practice part. Just wanted to add this in case anyone went down this route. Good thought process though👍
Thank you, @@jonsworkshop. But to keep the conversation going, doesn't the installation of the shims de-center the tailstock anyways? You are rotating it about the axis of the prism guide, so you are essentially introducing sine error. Seeing as our Host will have to realign the center anyways...
I'm just wondering, because I have a lathe that's very similar, and I'm going to be realigning and tramming the tailstock soon.
@@misterbreakit2006 hi, on any normal lathe I have ever seen and used I totally agree with you. This horrendous excuse for a machine however is different by way of missing material on the flat side of the bed. It is probably possible that taking up that gap whilst not messing too much with the vee side would fix the rigidity whilst keeping the tailstock on centre. All of that assumes of course that the tailstock centre height was correct to the vee side in the first place, which noting the missing material on the flat side is highly unlikely. I don't know how people can sell stuff like this with a straight face, absolutely shocking. Your reply is correct though, any level of scraping on a tailstock will alter the centre height. Cheers, Jon
That's a really good point, and I think I got trapped into thinking I needed to make the prism groove at least somewhat deeper if I wanted it to be wider. Thanks for all the followup comments @jrkorman, @jonsworkshop. I knew that whichever approach I took the tailstock alignment would be changed, but as I knew it didn't align correctly in the first place this wasn't a problem.
As I've commented elsewhere, I was inclined to go in the direction I did because it was a reversible decision. If the shims hadn't worked out I could have removed them and tried the other approach instead.
Shoutout to the Chinese bloke who messed this up… if it wasn’t for them we wouldn’t have had this excellent video!
I used reversed sandpaper on the bed groove, then moved the tail stock base plate and head over it to lower it end fit the groove. Parts are soft metal.
So glad to see you back with a new video. You have been missed. Thank you for a very informative, interesting and inspirational video. 👏👏👍😎
I had the same problem and solved it by making my own base for the tailstock. I have not finalized the machining of the shoulders as I have to do something similar for the headstock. and of course the saddle will require something similar. The only thing that will not change is the bed.
Always nice to see new content from you. Thank you
Thank you for this. Lots to do but now it makes sense where to begin.
"Repetion is the mother of Skill"
I love your attention to detail and almost phorensic examination of parts, etc. Given the Proxxon 250, CJ0618 and Unimat 3 - if you could only have one of them - taking into consideration; precision, handling and overall satisfaction of use - which one would it be?
As kokodin5895 says, remachining the V groove will solve all the problems. I have a similar lathe with the same problems, they all have as far as I can see. The V groove is 92 degrees so an end cutter on the mill will fit right to the top of the V without touching tho opposite side, I made a 44 degree wedge support to set the part at the right angle for machining. The tailstock was done first, I needed to widen the V groove by 1.4mm so I took 1mm off the side nearest the center of the lathe bed and 0.4mm off the outer face, it fitted fine with no discernable rock but lowered the tailstock by about 1.5mm so the top part had to be shimmed to get it back on center. A month or so later I tackled the saddle and headstock in the same afternoon, much the same set up but far harder to hold and very light cuts had to be taken. I cut the same 1mm from the far edge and 0.4mm form the front hoping that they would all line up as before when refitted. They fitted well but the down side was that the front saddle gib was now bottoming out on its screws so the gib seat had to be skimmed a suitable amount. Another downside was a visible crack inside the rear of the headstock, it only went part way through the casting but made me very careful when tightening the screws during refitting. Also the screw holes for the apron had to be drifted 1mm or so towards the front to stop the half nuts bending the lead screw when engaged as the saddle now sits a little rearwards of its previous position, it was lower as well but the leadscrew bearings had enough adjustment to allow for this. I still needed thin shims between the tailstock and its base to get the height right but I expected that.
The outcome was all 3 items are now sitting square on the bed with no rock, machining is now much more positive with less vibration and squealing, all I have to do now is improve the awful gibs in the cross slide and compound as they are just not solid enough, even when locked with the gib locks I added at the same time as I cut the Vs. I would say that as a rule its best to fix the problem rather than try to get round it, I considered shims at first but decided to go "the engineer's route" and machine everything to fit, after all it only has to be done once. My lathe came from Vevor and I complained about the fit of the tailstock, they offered me a £20 refund, I pointed out that this would not fix it and they upped it to £40, I looked at their website and pointed out that a replacement tailstock was £121 and accepted a refund for that amount. As it happens a new one would not help as they looked axectly the same, it might have been some work with a steep learning curve, I am a relative newcomer to machining, but the problem is solved and I am £121 better off.
Your videos are very instructive and entertaining and I have watched them all, how about a sub series Adventures With A Very Small Mill as your's is definitely in that category. Keep posting the videos.
Great work by the master👍
I don't know why but I thought you had done this 3~4 years ago?
For cast iron, an old vented brake disc should be more than enough to cut 'sheets' to shim headstock? (I'm sure you will find a use for the surplus)
Although if you wanted thicker, a solid disc will probably be around 10mm thick.
This video is of work I did a while back, and I posted a couple of still images at the time. The video was on hold due to family reasons, and then while I moved house. I wanted to wait until I had time to finish up the details, and do a decent job of the editing. I hope it was worth the wait.
On my little import lathe the headstock was misaligned with the bed by about .006" over 13" toward the operator and .010 vertically away from the bed. I scraped it in to get the horizontal error easily corrected by torturing a few inch pounds more on the screws on the V and shimmed the rear of the V and flat with shim stock. Once I could easily repeat perfect alignment by removing the headstock and replacing it several times, I waxed the bed and screws then put a layer of jb weld onto the bottom of the casting, put the headstock back on the bed, tightened everything down back into alignment, cleaned up the excess squeeze out and waited 24 hours for the epoxy to cure. (Same as bedding a rifle stock) The headstock now has 100% contact to the bed and is aligned to the bed to within .0003" both horizontal and vertically. Alignment was done with an mt3 test bar and 4" machinist level.
Great video! I have learned so much watching you work on this import lathe. I have one also and I'm experiencing many of the problem you have shown. Your vids have helped me to know what to check and how to go about fixing the problems with this lathe. Thank you so much.
How will this correction affect the alignment of the tailstock with the head?
It's going to affect it a lot, but fortunately the tailstock was already badly out of alignment, so nothing serious lost. I'll have to rebuild the rest of the tailstock and fix the alignment in a future video.
Always scrape next pass crosshatch to previous, it will give you a better surface. If you need to peel off more material use just double passes with crosshatching directions. Use red oil based paint it's more contrast on metal.
Keith Rucker at Vintage Machinery is one of the best sources on scraping on RUclips. Search him up and you will find many videos. Just watching this, I suggest cross hatching the scrapes. Scrape at an angle and then go back with the opposite angle to make Xs. Good work on your first attempt!
Keith has been an inspiration and a source of knowledge since my earliest days with machining on RUclips, but when I was digging up resources for this video I had trouble finding the most useful videos in his enormous backcatalogue. If you have any particular videos of Keith's you think are most worth learning from, please drop me a link via email (in the channel About tab). (Unfortunately RUclips deletes comments containing links).
@@AdventureswithaVerySmallLathe - Sent! FYI, the email is not available in the Android app. I had to go to desktop.
What kind of paint should I use for this?Brand, type? etc.
I always use Paragon Paints for small machine painting. They are good quality, and they have matched colours for the original manufacturers tone. I'm not sure how widely available they are, but worth a try.
@@AdventureswithaVerySmallLathe I don't know the brands you mentioned. In fact, I don't even have the means to reach them. I'm curious about what alternatives there could be instead of these brands. For example, what type of paint is it, acrylic or oil? In other words, is it a product that is much more affordable and easily accessible? I'm looking for a solution though. :)
The type of paint is machine enamel. I'm afraid I have no experience of any other brands.
Are you talking about paint for the outside of the machine, or the blue marking compound used for scraping? If you mean the blue compound, then it's generic name is "micrometer blue" or sometimes "engineers blue". The most common product is "Dykem Hi-Spot", and in the UK there is "Stuarts Micrometer Engineers Blue". Do not confuse this with layout fluid which is the same colour, but rapidly dries after being appliesld.
You can probably find recipes for home made versions, generally using a dye called "Prussian blue" mixed with a grease.
Two thing's:-
(1)As far as cutting or scraping a metal piece of any type of metal goes make sure that the metal of your hand tool/any drill bit is of a harder rigid material than your subject/workpiece. In this detail, carbide work tools, blades, and drill bits are the most preferable and the most bang for your money as they last a long time, and the fewer times you need to make any adjustment to your tools and drill bits the better.
But there are times when your workpiece metal/materials are too soft for your carbide tools so, in that case, you have to work with a tool that has a tier higher hardness than your work metal or closest to it for example:- workpiece metal hardness is tier3/4 than your working tool metal hardness needs to be tier4/5 and so on. If I am correct the carbide tools hardness typically is between tier7-10 so you will be good to go on most projects.
(2)Widening the groove in the x-axis and make sure it's all the way through the whole length of the groove in the y-axis while leaving the depth in the z-axis the same as you could have used your blue ink you have applied it on the face of the groove & sliding place piece while having them aligned with each other and
having them clamped in the right spot and getting an ink impression on a thick paper or cardboard you could have figured out how much you need to mill the width of the V-groove equally on both sides overall and get the exact milling of the metal from the workpiece just right.
The way you did it is for when your V-groove is flush with the track but your opposite quanter support section has too much play in the Z-axis and needs extra material to support it so it can be leveled with your track to speak off.
Always look foward to your videos
Dont forget the clamping of the tailstock might cause deflection. I think its a good place to stop on that part, the significant wobble is gone.
At the same time would it not be easier to remanufacture the base plate? With the time invested in the project?
I'd still have to go through much of the same process to get the new base plate to fit really well, so it certainly wouldn't be easier.
I understand why you couldn't deepen the groove, but was there a reason you couldn't widen it, giving it more space to sit further down on the prism way without removing the strength of the part?
That’s exactly the thought I had. The main reason I can think of to not do that is it looks like there isn’t enough material to operator side of the lathe, so essentially all of the material would have to be removed from the inboard side, which would cause the block to move towards the operator. This could be enough movement that the tailstock is no longer able to properly center with the headstock, making the whole repair pointless.
Unfortunately it just seems to be an extremely poor casting. Too bad these manufacturers aren’t willing to spend an extra $1 to have the castings be slightly larger which would allow buyers to properly mate parts.
The hard part is getting the center of the tailstock to align with the axis of the spindle in the headstock, while at the same time being parallel with it.
Tell me about it!
I've thought about how I'm going to approach that quite a lot, and still haven't settled on an approach I'm confident will work. It'll be another great learning experience.
Very nice. I enjoyed every minute of it.
Hi! . There was one guy from UK that made a PPT how he made "epoxy way shims" making a composite out of bronze + graphite + ptfe powders and epoxy making in tokind of "boots" for each sliding surface.
I have a question. Wouldn't it be faster, and perhaps with a better result, to use fine sandpaper? Place the paper on the bed of the lathe, fix it with clamps. Attach the tailstock and move it slightly and let it grind?
I was apprenticed as a machine tool fitter and was lucky enough to have worked on all manner of machine tools. The best by far were British and German. Makes like Herbert, Asquith, Wickman, Jones & Shipman, So-and-so etc etc. Having seen these Chinese made lathes and milling machines and tried to use them, I am appalled at the quality. It makes me sad that nearly all of our machine tool industry has gone and people buy this rubbish. All of the old engineering colleges have gone that used to have good makes of lathes like Colchester, Harrison and so on. These old makes are still around as in used condition, but after 50 years or so are still far more accurate than the rubbish made in China today. Colchester lathes had a motto on all their machines which read "the world turns on Colchester lathes".
Its a bit late now but I use a thick tipped Sharpie marker in blue for my layout work.
I'd recommend using turcite it would prevent wear on the bed of the lathe.
Can you stick some adhesive backed sharpening film to the bed surfaces and prism and just lapp the carriage against it?
For a cast iron, you need negative rake, and you controll depth of the cut by downward pressure on the scraper. And rake angle is important, depending on the type of the iron. 5 to max 8 degrees. Thin the blade so you can reach tight spots. Its just angle on the edge that counts. blade itself can be tappered or whatewer.
For a mild steel, you need to grind positive rake, but also need to grind a "heel" (like on engraving tools), and you control depth of cut by changing the angle. Steel can be scraped very nice that way.
Check An Engineer's Findings clip about it.
For polishing the edge.. just make block of some realy hard wood like locust, hornbeam or similar, with 95 degree angle. Notch that edge for about 1-2mm. Flat brass stock and diamond paste... Put the insert on one edge of wood block, brass stock on another and you will get a guide for your 5 degree rake. Remember.. carbide do not like to be grind or honed away from the edge. It is so hard that it will microchip the edge.
Change dirrection of scraping for 90 degrees on every pass, so you avoid chatter.
Findings of an Engineer has some tips on scraping steel. The negative rake is for cast iron because it's brittle. Positive rake for steel but grind a heel so you don't dig in too far. Scrape for bearing on the tail stock, like the other guy said. A HSS scraper should last for several passes on such a tiny area.
As far as hacksaw blades go, try out a Starrett blade. I switched a couple years ago and it makes a world of difference.
Thanks for the tip! I'm hoping I can sort out a vertical bandsaw that makes cutting sheet steel like this easy, and I think I've heard Starrett bandsaw blades are worth the money too!
When using a hacksaw, it is best to make long, fast strokes. And positioning yourself so your arm naturally moves in a straight line can improve the cut too. You will be amazed how fast and clean your cuts are after a little experimentation. Manual hand tools are extremely powerful and make less mess when proper technique is used.
excellent work on this. your mistakes really add character to your machine and great content to your video. Keep it up, looking forward to the headstock
What !? A new video from a very small lathe ! I'd be damn ! Welcome back ! Love your videos !
I really need a full version.
The next part is nearly done. Should be out within the next two weeks.
Your thought process and attack philosophy is sound other than choosing mild steel for the shim pads. The JB Weld raised your pads and caused more scraping than necessary. At least the contact area increased. Now is it parallel to the ways? Clamp the tail stock base to the Ways to check for parallelism. The Headstock will be very hard to resolve. IYour approach with the Tailstock with shims and a skim coat of JB Weld and scraping to creep up on a proper fit might be your best method.
Would it have been easier and more precise to use the mill on the flats and angles?
So thrilled to see a new video from you🎉🎉🎉. As bad as it is, id be tempted to just make a new one, but fixing it is a good project too.
A few things...
Go in alternating directions when scraping... You cant just approach the material from one side, you have to cross your scraping marks, kinda like how you sand stuff, you do it from one direction and the next pass is from another angle across the prior one... It prevents you from making furrows or grooves in the surface, and results in points, rather than streaks of contact...
You are getting nowhere apparently most likely as a result of working on that exact combination of V+flat ways, as any level of angular change or change in fit in the V groove instantly tweaks the flat way contact...
Scraping is an art, and reading and understanding the printing and relying on other checking methods is quite tricky, as you have to know what influences what, and how stuff will interact with ways in perfect situation, and how any deviation from perfect fit will change the picture that the printing shows...
I would most definitely try and mill out the V groove a bit before the job, its not so flimsy as to be unable to be milled down 40thou or 1mm... That would have deepened the contact area, and could have allowed you to fix the fit of that section tremendously, allowing you to merely focus on scraping of the flat sections until you get a perfect fit on that side...
Also, for a proper intro to scraping, go to Gtsw Stefan`s channel and watch his work, and go to Robin Renzetti`s channel and watch his work in that area... They are invaluable as a source if you want to start scraping and between them, you will get enough tips and directions that if you ever have any questions, it will be the result of forgetting what they said and will return you to rewatch their videos as i have multiple times...
All the best!
Steuss
Thanks for the detailed explanation! I think that's help me understand the need for alternating directions better than I did before. Stefan and Robin are already in the list of videos I've viewed, though I definitely understand their videos much better now I've had my first try than I did before.
Congratulations on setting up your new RUclips channel, you have a new subscriber!
@@AdventureswithaVerySmallLathe
Ayy, thanks, and anytime...
Glad that you are interested! I will be posting a ton of machine related content as time goes on, but at the moment, things are more than just a bit chaotic, to put it mildly, so things take even more time than i would usually be okay with...
I see that you have been posting for a relatively long time now... Yet i just found you today... Strange how you get to find channels that have a long history on the topic you have been following for over a decade, without ever seeing them before... Sometimes all i get for weeks in my home page is stuff that i have rewatched at least 3 times by now, and there are dozens of channels that do things similar or related, yet you have to somehow dig them out yourself before youtube will ever show them to you...
All the best and kind regards!
Steuss
Yes the adapter looks very interesting
And after all that, does the tailstock center line up with the spindle?
Nope, but it didn't line up before, and there is no point in trying to line it up until I've fixed the bed fit of the headstock, which is just as bad.
I'm sure it's already been mentioned but... Grinding the groove doesn't involve grinding it deeper. You just have to grind it wider. You could grind all of it off of the outside edge so the flat would move over the way more also.
Wouldn't sandpaper (or other abrasive) achieve the same (or better) result as scraping?
The trouble with abrasives is that there isn't enough control over where the material is removed.
For some reason I have a sweet spot for “improving sub standard mechanical devices”.
Your video editing, voice over, approach to the task at hand…in the top tier in my opinion. 👍
About the bench grinder, I would love to see how you made the diamond wheel adapter as well as your approach to some upgraded grinding rests. No pressure 😊
Thanks once more for great content.
Thanks, I'll add that to the video list, though I can't promise when it'll come out. I'll probably go for a lighter-weight video than usual, without quite so much detail.
Not going to claim I'm an expert on this or anything. But I think there's a problem with your procedure on this one.
Basically, as you scrape away material on the shims you're rotating the casting about the angled ways like a fulcrum. So until you're getting flat contact on the shims, the contact points on the other two surface would be changing as you're scraping the shims. As well, you're also essentially moving the fulcrum at the same time by scraping all three points, so you'd have to move relatively more material from the shim to see any difference.
To me it would make the most sense to only scrape the shims until you were getting pretty even contact along it's length, and then start scraping all 3 surfaces to bring it down evenly.
My thought process was that by removing material from all three surfaces at the same time, I was keeping the rotation around the fulcrum to a minimum. From the first print I took I knew the back of the base was still tiny bit too low, so I didn't want to make it any lower, so I wanted to make sure I kept taking material off the prism groove to keep lowering the front at roughly the same rate as the back.
@@AdventureswithaVerySmallLathe ah, understandable. It seemed like in the video, with the high spot being towards the back of the shims, that the rear end was up higher. If the top was level though then of course you'd want to keep that.
Either way, I'd suggest reading "Machine Tool Reconditioning" by Edward Connelly if you haven't. It's got a lot of great info that takes everything into account.
I'm wondering why you didn't establish your high points before you started scraping?
The idea with scraping is that you only scrape the high contact points. The areas that rub first. And expand as the contact point becomes more even.
Personally, if I was ready to make pads for the machine, I'd hog out a spot to install a larger piece of metal right across then machine it down and even. Use Emory on glass to flatten it, then check the contact pattern and scrape from there.
Hard to say what the best method is given how much slip there is in your machines
Nice work! Im going through the same modifcation. How will you align the the headstock to the tailstock? Are you planing to mod the tailstock for adjustment? You could use self lubricating bearing brass for the sadle shims.
Great job mate, really enjoy your videos, therapudic watching you work through and learn as you go. Cheers mate
Put 2 pre flated set screws as a 2 leg, and adjust them to parallelism required, then put some loctite to fix the set screws.