I work with cutting edge CNC machines and have access to any tooling I could ever dream of, yet I rarely do works that are as interesting and well thought out as this. You certainly have a vision and a way of achieving the results you're after with the proper means, all with humble machines, and a good mix of home made tooling (and tool!). This is seriously impressive for anyone passionate about restoring carburetors, as well as hobby and professional machinists. But not only that, the video is filmed with great skill. It is so difficult to film machining because of various reasons, notably lighting of highly contrasted shiny metal parts, chip management, focus, and knowing that you usually can afford one take for each operation. All in all the video has a good pace and excellent sound. I feel like I'm watching This Old Tony again, without the dad jokes. Keep it up man
The problem with CNC machines is that they have a strong tendency to remove the worker from the part. After all, CNC machines have two different jobs. The first is to make lots of the same part as quickly as possible. The other is to make cuts that are not really possible by hand, those very fancy things such as blades for turbines.
The premise that you a running with, of buying obsolete parts well past the end of their life and giving them a freshening-up to make them serviceable again is something every hobby or amateur machinist should be aspiring to. For the people that own those vehicles, that refurbished carb body is worth a lot more than the time you put into it (scarcity being the driving factor) and so you have a nice niche to keep your shop busy and pay your costs while helping others. That's my kind of shop, right there. This kind of out-of-the-box thinking can be just the inspiration someone needs
Thanks! I also enjoy this type of process and the decision making involved to achieve a certain look at the end. Expect to see more of this in channel.
a lot of machining videos on youtube show hobby machinists making a lot of tools, but usually they are making tools so they can make more tools without ever showing them making an end product with their work. It's very gratifying to see shop made tools put to a specific purpose, especially when done so cleverly.
It depends on what we’re doing. Sometimes I have to make a tool to make a tool, to make a tool. The end result is a tool to allow me to make a part that otherwise is too difficult, or complex to make otherwise. Sometimes I can make a tool to directly make a part. Most of the time I already gave the tools, or I just buy them. RUclips requires people to make a fairly regular series of videos in order to make any real money because viewers want regular videos. So it’s a matter to come up with projects. A lot of people like to see tools being made. So I wouldn’t criticize either way.
Reamers only ensure that the hole is to size, location wise they offer no guarantees. Boring bar is the way to go when you need the hole to size and in the right place.
Lol , a properly spotted and drilled hole can locate a hole within a couple of tenths . The reamer will follow the the drilled hole maintaining the location established by the drill.
I don't know how your channel escaped me for so long. I think your mix of tool making plus using said tool is perfect and this good balance might be unmatched on youtube. Thanks for the satisfying content.
I retired 6 years ago as a jig and fixture maker. I liked your video. I just wish I could have had the quality of tooling you have. The people I worked for cried like babies wen I asked for new or different tooling.
I turned a female and a male taper much as you did here and they, as yours did, not match. Instead of remachining like you did, I used a grinding compound and lapped them to one another. The final fit was 100%.
@@nbrworks Good choice in general., Lapping tapers is tricky and generally doesn't result in a constant taper, because you can't move the parts axially so you end up with rotational symmetry and matching parts but not cones. Fine if you're making two parts to fit each other and nothing else, but no good for making anything interchangeable.
One thing that can mess you up on male/female tapers fitting properly is the cutting tool has to be precisely on center height wise. Most machinist are trained to run the turning tool just low of center height and a boring bar just a bit high on center. That will make the angle wrong. Some people know this and some do not. Just saying that is something I had to learn the hard way. Fortunately I was working at a job shop machining a big coupling to fit a tapered shaft so I got paid to do it wrong then got paid to do it right. Cost the boss man a $400 coupling.
24:45 This is PERFECT .. the idea that this tool can easily be used 1000 times, and never change accuracy or strength is very awesome!! In my opinion WELL worth all tis effort, the cost in materials is negligible too!!
I was a mechanic in my early life, '60-'92 & spent some time in pergatory working on British & other sports cars. You have found a a way to solve a problem plaguing us back then, premature wear of throttle shafts on down/side draft carbs creating vacuum leaks & 'no win' tune ups, (performance/efficiency is improved w/ new ignition parts, but rough idle, surging or stumbling can't be fixed, so "Your tune up was worthless". That no win situation caused me to add the extra work of compression tests to all tune ups & reject the candidate if imbalance was found in cylinders. Didn't solve the problems w/ the carb shaft issues & complaints re: "bad tune ups", but it eliminated most of the complaints of "bad tune ups" due to imbalanced compression. By nearly eliminating the one, dealing w/ the other was easier. It was still like talking to the wall most of the time, since most customers thought a tune up would solve everything wrong w/ a 125,000 (hard) mile sports car. Nice work, nice design, clever idea on driving the custom mandrel. I like it enough I may add the drive design to my list of tool upgrade projects. It would be nice to eliminate lathe dogs from mandrel work, if I live long enough to get to it! LOL I laugh in the face of old age & mortality; as long as there's work in my shop, I'll keep going. And... there's ALWAYS work in a shop. ;-)
Very nice work. I once repaired an Obsolete Marvel Schebler carburetor for the engine of my brother’s airplane engine. Was challenging to say the least. I miss making parts for his home built airplanes.When he called me, I knew it was going to be something interesting.
A very thoughtful piece of work holding. If you intend to use the mandrel alot, have you considered drilling a hole at the root of the slits? If you are concerned with fatigue it would be a good idea. Thanks for the video.
Brilliant tool making for a job you felt needed this precision. It looked to me that the castings were very cheaply made for the application. You created a better part that will hold up longer. I hope you price it accordingly.
Wonderful video! I’m a vintage Volvo enthusiast with far too many su carbs in my shop. I’m just getting going on my machining journey. Really looking forward to your video on the chamber /pot refinishing!
You've done an amazingly beautiful job of both the internal collet and the finished carburettor! ♥ The only reason that I can think of for the brass rod sticking is that I think a bushing and the part passing through it are usually made out of dissimilar metals - e.g. steel and bronze, etc. - it may be that making both from brasses that are similar may cause problems. I sometimes use adjustable reamers that can be adjusted by maybe c. 200 μm or 8 thou - that lets the reamer be adjusted to get exactly the sort of fit that I want. I've heard of a soft wood rod or plastic rod being turned to the right size then used with some grinding paste as a hone to very slightly increase the diameter of a reamed hole and give a surface finish which holds lubricating oil.
I would just use some lapping compound. It's kind of a lousy set up, it has to be loose enough to pivot, but not so loose that air can enter the butterfly valve. Seems like it needs an o-ring somewhere.
This is a MUCH better and longer lasting repair than how I would have done it.. Years ago there was an aftermarket company who made these little stuffing box cap things that slid over the shaft and mated tight to the carb body with friction (they kinda looked like a valve stem oil seal). I like your repair much better!
You could also look into the tapered mandrel expanding bushing that is used between centers for turning or grinding bushing OD. You can make a special arbor with threads and a nut to push the bushing into the long taper.
Great work! when setting your compound angle, mount an indicator on the toolpost, square to the workpiece. You can then set your angle based on the travel of the indicator vs. the travel of the compound. For very sensitive angles, this will get you closer than the graduations on the compound can.
A tip: Loctite does not like zinc. If I end up with galvanized or Zink plated bolts Etc. I soak them in vinegar, which will dissolve the coating, then steel brush to remove the "Rust" from the vinegar.
Suspect part was rotated on angle plate and realigned for each bushing hole from the quill. A dividing head or rotary table required to achieve perfect alignment of the holes. ( you have an engine lathe and a knee mill, could build one. ) Side notes, Red Seal trade school hints from Canada: Hand hone rads on the corners of the cutting lip to lands on twist drill when the chisel point has no material to keep it centered, cuts smooth acting like a reamer. Blueing should never be smeared on full periphery, 3 equally spaced thin lines on taper angle and the mating part is twisted 1/4 turn max.
If you bolt down the carburetor flange with the sticky shaft, does the sticky go away? Just a thought. I know with the aluminum LS block, the crankshaft is sticky until heads are bolted on. Great Video. I once dreamt of restoring vintage carburetors and now with a mill and a lathe you make me rethink having thunked it. Thank you
I have a box of different expanding arbors one set will chuck up in lathe Jaws or a collet, the other end a cap screw, they expand parallel, bought this set in the 80's, don't know if anybody still makes them.
37:47 What you might be seeing is the rigidity of your setup or machine. The Z-axis tool pressure may be deflecting your table, combine any other variable and it can easily add up to this amount. Try measuring the movement of your mill table when locked down with an indicator. If your machine is deflecting or twisting it can cause unpredicted tolerance issues. Then, as usual, make sure your mil head is trammed in. Great video and ideas!
I have a very old Tillotson book from the 40-50's, they made special piloted style reamers and bushings for reworking throttle shaft bores. Too bad there isn't anything like the today. Believe it was setup so you ream short of the venturi to keep that surface round.
I’m only partway through the video and I’m already seeing a lot of old-school techniques here. Many things were bored, turned machine in what would now be considered oddball ways back in the day. Your idea of using a ring on your expanding arbor is spot on. One thing to remember about turningmaterial that has been cut into segments is centrifugal force is pushing the pieces outward as you are trying to machine them. If you’re not able to use a ring to hold everything together, you may have to run slower RPM and take multiple cuts.
Can you imagine the cost of what you just did, if you were charging for a one off part restoration? E.g., I just restored an old Minolta camera, it took me 25 hours to complete and for that I didn't need to make any parts. The camera cost me £23, the best price I'd get for it would be around £100, so at a modest charge rate of £25 / hour, that would be £625, that's £525 more than the camera is worth.
you would get fairly more accurate hole positions for the rebushing operation by using an endmill for the first hole opening, after that using drill might be okay, but in essence endmill evn held in a 3 jaw drill chuck tends to produce more accurate positions even when the spindle/quill rigidity is compromised due to wear on the machine. in general, long spiralflute HSS drills tend to wonder towards the center of the already present hole as that position results in the most balanced cutting action on the two edges of the drill while the body is relatively flexible, while endmills just dont. behave like this, they are totally fine with going in off of center of the existing hole.
Nice job. No reamer, is adequate for straightening a hole. Mandrels sre awesome. I would have bought a cheap expanding mandrel. Your way worked just fine
Hi NBR, first time here, great to see you working so clean and precise. With interesting explanation and approach to all the aspects and problems of the job. Great video work also. Many thanks! Just one point . . . it would be nice I think to have some drawings or at least sketches, to follow along.
Awesome. Not really applicable probably since most people don’t have one on hand, but jig grinding these two bores would be the way to go to get them dead on in line with one another. I ran a Moore No. 2 at one point and super precise hole, slot, etc. location size and alignment were its specialty. Thanks again very glad to have stumbled onto your channel
Use an adjustable reamer with a guide pin to finish the bores of your bushes from either side. That will correct your out of alignment issue. A reamer will only follow an existing hole, and your extra long reamer almost certainly deflected slightly to do the second hole.
Nice job! A very novel idea to fix a very real and common problem...I'm not a machinist but just retired and I hope to get a mill/drill very soon and I anticipate learning a lot from you...I've watched a few of your videos and like what I see!
I imagine the reamer did deflect, when you where talking about at the end of the video. Have you ever put an indicator on the end end of the reamer while it’s chucked up in the spindle and touch it with your finger ?It’s amazing how much long tools can deflect and with such little force.
you can def do this in a mill. you use something like a mitee bite ID expansion clamp. which is essentially the tool you made...but the mitee bites are flat on the bottom. for holding round parts in a mill :)
Both bodies were not originally a set, I'm pretty sure I have mixed up some parts looking for the best ones to make 'my set'. But looking at them I wouldn't say they had 0.5mm (actually more) of difference. Some of these bodies don't have a take off for the distributor vacuum and others don't have a way to mount the choke lever cam, that's why I mixed and matched until I got what I need. Thanks!
As a beginner, (just a few, cancer interrupted years ago), I wondered & asked if angle of contact of the insert & the material made a difference. Didn't get, or find an answer, so just kept on w/ getting a working contact within the size limits of my hot rod Sherline, (too little tailstock extension, no compound, tooling & toolpost a bit too large). A few more years into learning, some new tooling & I'm discovering the angle CAN make a difference. In situations where you're getting ling curly swarf, try changing the angle of the tooling. My theory is the cut coming off the material is missing a portion of the insert which will change the path of the swarf & cause it to break. This also depends on the design of the insert's chipbreaker; some it won't matter. Be curious to hear your results if you play around w/ this.
That was some nice machining, parts turned out well, far better than the original manufacturer ever considered possible. I am a little surprised you didn't radius all the internal sharp edges while you were in there with flex shaft grinder? Back in the day it was much more common to have sheet of emery paper on a flat surface to correct bow on flanges, exactly how you did it. Milling machines were a 'luxury' few shops had and cost at machine shops was far too high for majority of people. There were aftermarket kits for the bushings, just drill them out and hammer them in (then spend time with a file and emery cloth fixing the burrs). I imagine they have been out of production for 50 years or more by now though? You should have drilled holes at end of expansion slots, it would mean there is less material to flex. You could still do it but will need to use a center cutting end mill. Using Morse taper adapter as an extension for center may give more clearance but it's going to be very flexible when you have any side loads (as in turning) and probably reason for chatter? All in all, a very interesting video. Are you (or have you) done a video on rebuilding the SU carbs? I had them on my first car (1966 Rover)
Hi, nice to have you back! I might add some small radius in certain points, but I want to do it carefully and focused, not in an awkward position with the camera in the way. I believe Burlen in the UK still sells service kits. I have one I bought several years ago, it came with steel bushings, coated with teflon inside, but in my point of view, they leave a little bit too much play for the shafts. That's why I didn't use them. I also believe Burlen replaces them, as in a service they provide, but I don't know details about that. Regarding the holes at the end of the expansion slots, I will do them, like you say, plunging a center cutting endmill, this was also suggested by other viewers (thank you). The morse taper extension... it's a good point. I bought the extension because I needed the clearance, but I also thought it was going to flex a lot and be unreliable (or reliably give bad results). But in fact, I can't complain. At 2:02 there's an example of that. Until something changes, I'd say that extention is working for me. At least it's better than having the tailstock fully extended 😉 Video with the full rebuild of the carbs... no, I haven't done that yet. I still need to take care of some things first: pistons and chambers, choke mechanism (I need to invent something to make it work), take care of the manifold, air filters, etc. But I'll make that video, that's guaranteed. Thanks!
Love the quality and thought put into your machining. Its great to see some decent but appropriate size cuts taken on a lathe. Also given your results you have adjusted it perfectly so while not an expensive lathe you are getting everything out of it you can. By the look of the chips you could up the feed a little or the speed to help get the chips to break up. On a more important note 6 jaw chucks are for holding thin wall workpieces. They help lessen the amount of distortion. On anything else you can't be sure that you actually have the 6 jaws working - only 3 of them may be (think of stools chairs etc.) depending on the workpiece. So it is best to use a 3 jaw for most work - though it doesn't look anywhere near as cool.
Hi in the racing game a little goes a long way, heat expansion, long time corrosion from fuel,s ,what you are achieving helpes me a long way, thank you for your time in making this video, cheers mate 👍
RUclips/Google recommendations is magic. I just finished a expanding mandrel today. I have not searched for anything regarding expanding mandrels (just made it from my own idea in my head). And then i get home and is recommended this video the same day...
Maybe I missed something, but wouldn’t it be safer to cut the expansion slots last? I was so nervous watching it turn on the lathe with those slots, expecting the cutter to grab the piece and shred it.
As other's have probably pointed out, the reamer is not necessarily going to correct the bore alignment, a boring bar is the best way. Maybe bore/bush one side, flip it and then run a ground shaft up through it and indicate off that shaft, then bore the other side. You could also set up a mini line-bore arrangement on the lathe. I'm sure there are other ways as well.
This is art work. And well done on a completed project with excellent results. Again a coupe of comments (I left some in the butterfly spindles video). Why not use ball bearings on the spindles? Weber does it, Dellorto does it, I am sure others too. Technology has come a long way and we now have pretty much any size and flavour you want. Have a look at hobby (radio control) shops and see the diversity of sealed bearings in any size you can dream up they offer these days for not much coin. I have used them in carburettors for a while now with great success. No more shaft wear, no more bore wear and much better sealing and reliable positioning than you can ever dream to achieve with metal on metal running clearances. Not to mention smoother turning. In your case all you have to do is add a counterbore to the outside of the spindle bore on either end to house the bearings and threads to the spindle ends. If space does not allow for a very large bearing, just make the bore deeper (I have noticed the bores are quite deep) and put two bearings back to back on either side. Either way, in a carby these bearings won't see the loads they are designed for so they're basically in there for life.
I make a lot of mandrells as well, far simpler, just to support the bore of carburettor bodies. There is always a side bore in the body, at that location I make a threaded sidehole in the mandrel mostly M5 or M6 and secure the carburettor body from sliding of by using a bolt and washer . the carburettor body must be in line but is allowed to be eccentric so any surface that needs to be flat is perpendiculat to the axis but the cutting grooves to flatten the surface do not need to be concentric with the internal body bore . pistons alike if they need a new circlip ( retaining the piston pin ) groove
If you don't mind the suggestion, I think that you could probably have put less stress on the expanding mandrel if you reduced that cone angle to about 5°relative to centerline. The one you have there looks like it's about 30°relative to centerline. You don't have to expand it very much in order to get a tight fit. Regardless, I think you did an exceptionally good job in devising that tool..... And I'm happy it worked out for you! 😄
Thank you for a very informative video however, the one question I have to ask is what fuel will you be running the engine on that will pass through the carb? If it has an ethanol component, the brass bushes and spindle will corrode and cause all the same type of issues that you are attempting to machine out. I would use a Delrin bush and a stainless or silver steel spindle that can be bought in certified diameters. Its interesting to note that the Brazilian Solex carbs have next to no brass components because their fuel either contains high volumes of ethanol or neat ethanol.
Hi Clive. That's a very interesting question. I've seen the concern online before. I remember reading a thread in some forum where someone tested some materials in some jars with ethanol... as far as I remember it was not conclusive if it would cause a problem or how long it would take to cause that problem. My first concern is the float bowls which are thin brass and are in constant contact with fuel. Currently I can still get (supposedly) ethanol free fuel, but I don't for how long it will last. Do you have something or a situation you'd like to share about this? I'm interested to know more. I'm aware I need to get good rubber hoses (Gates maybe) and even with those not expect them to last more than a couple of years.
@@nbrworks The issue with ethanol is a common one that is well known in the classic car world. I have seen various renovations documented where the brass components of carbs have corroded, which is unusual to say the least, usually the brass elements last considerably longer than the other metals around it. These examples were based in US where eithanol has been used for some time and the machines were left for long periods with fuel in them. We are talking prolonged periods so that testing would have to extend over years and not a few weeks. I have an aircooled VW Beetle with an electronic fuel pump that was initially an old faithful that I purchased many years ago before ethanol was added to fuel. It served reliably in various vehicles, including the Beetle until ethanol was added to unleaded and it expired not too long after. The replacement pump is identical although, Facet the manufacturer, specifically states that it is suitable for ethanol added fuel. It might be a coincidence that the original one failed but the timing was noticeable. Also the Beetle is fitted with a Brosol carb (Brazilian Solex) that has fewer brass parts than the original Solex carb and given that Brazil has a high usage of ethanol, I would expect that is the driver for the change. If you are changing rubber hoses then the safe ethanol resistant quality is R9. Unfortunately, R6 is commonplace that is slightly resistant and that is what you will mostly find in the motor factors. The brand is not so important as getting the correct spec SAEJ30R9, which will be printed on the hose. The other issue with ethanol fuel is the longevity, with E10 'going off' within 2 months, E5 within 6 months and non=ethanol fuel lasting 12-18 months, which is important for classic car owners and horticultural machines that may stand for long periods without use and a fuel supply can sit in a can for months.
Gaskets are usually expected to make up the difference in minor defects, and warpage is to be expected from being "handtightened" over and again. Eventually you will run into a leak that cannot be solved with more wrench or the application cannot risk liquid gasket maker seeping into the orifice. That is definitely when you need to consider surfacing like this
Aw man, a proper SU crate O.o SU's are still made up the road from me in Salisbury in Wiltshire and also cover Zeniths, Solex and other brands of vintage carbs. Do love old vintage crates and wooden boxes for putting stuff into, just adds a bit of gravitas to your stuff in my opinions :D
Very nice. Some years ago I did a similar carb refurbishment job, but in my case I made the arbour to a shrink fit. Heat the carb in boiling water, push it in place, machine, then heat both the carb and the arbour to 150°C and they released perfectly. If I were to do the job again, I'd make the arbour to a slip fit and glue the carb in place with CA, releasing with acetone or some heat. Not as elegant as your solution of course.
Way too complex. Not the way I would have done any of this. I would have simply purchased a hardened 1.250" diameter mandrel with an R8 collet shank. However, it worked and produced the dimensions you desired, and should be repeatable in future use.. Maybe lap in that sticky shaft, although you will never feel it with the pedal against the return spring setup. For the best possible seal you could have added O ring pockets or grooves on each side of the shafts.
Impressive work and very nice video to watch and listen to. Regarding the pairing of materials, am I correct in assuming that bushing and shaft are of the same material (=brass)? That would lead to a higher wear rate than pairing dissimilar metals. I'm used to seeing steel shafts running brass bushings or in absence of those, in the aluminium of the throttle body itself.
Great work :) , not being an engineer by trade you learn pretty quick its not the tools that cost but having the correct measurement tools so you can actually do stuff and then its endless if you have the skills (and the right lathe ofcourse) - Keep up the great work
The reamer can and will not fix if the bushings are off axis or off center to each other - remember its a reamer not a endmill, it will follow the bore no matter how off they are, as long as it can bend as far as it needs to.. if you're getting uneven pressure from the lower hole, because its off center or off axis from the top hole, the reamer will create a hole with a notch in it form bending, or it might even get oval, even worse it will be different along the length of the hole - the top might be bigger to the left side and going down it'll get bigger to the right side of the hole. Thats exactly the reason why it isn't recommended to use a reamer in that way, unless you're absolutely sure the holes are perfeclty in line with each other. Nice work, really nice attention to detail 👍🏻
This is fantastic, many thumbs up. Chinese lathe (that's what I'm looking at for a size upgrade from my most excellent but too small Sherline)? What brand? Which model? It looks like you have personally tricked it out to the n'th degree. Any information would be most welcome, thank you.
Hi there. I have a rebuild series of the lathe, you can check my older videos. The lathe is from HBM Machines, it's the equivalent of the Precision Matthews PM-1022V, if you are in the US. I haven't scraped it, I just carefully rebuilt it with minor changes. I'm working on a related post that I'll publish on my website soon.
Not sure I would have done the partial bushing, you dont want that remaining bit becoming loose over time and maybe falling into the carb and wedging the throttle open or affecting AFR due to blockage in the inlet.
The ring left is part of the carburetor casting - it's aluminum. There's no way it will become loose. Sure in theory it could break in pieces - but I don't see how that could happen - there are no forces making that happen - it's just highly unlikely.
No, no, the old bushing was completely removed and the new one will be stuck between that aluminum shoulder and a clamp that bolts onto the shaft (not shown in the video). Worst case it gets loose and rotates, but it will not come off. Thanks (glad you got it with my explanation).
31:24 I wonder if an 'oldham coupling' would be a good choice for this, unless it needs the 'give' and spring the metal can provide. But it just seems more built to cost. Also modern day 'spring couplings' like those used in 3d printers could have those properties and likely better concentricity.
Yes, there are better functional choices, but something I didn't mention in the video was 'looks'. Being for a classic car, I'm trying to keep these carburetors 'in period'. That actually influences a lot of decisions. Thanks!
It is absolutely amazing, the ingenuity machinists use to constantly improve the quality of their work. Now if I could convince the garbage collector to adopt such a strategy to find ways to do less damage to my cans.
He sounds like a guy that's probably in a place that uses a lot of metric and British straight. British taper would probably be more common in EU than NPT. But I wouldn't know as I have never had to plumb in Europe 🤣 But taper threads definitely sounds like a better idea if he's not running an expander plug with a matched angle. Less work involved, off the shelf replacement parts.
great work again, thank you very much! 👍 why did you use such a long boring head to bore the bronce bushings and the chamfers...i would be afraid of chatter...although they came out great, so what : )
Hi, nice to have you back! It was a matter of using what I have available. The boring head takes 12mm tools. I don't think I have any broken tools with 12mm shanks (to grind), and the 6mm boring bar shown at 8:16 looked perfect for the job, including the 12mm sleeve (coincidence?). I thought of cutting it in half, but not without trying it first. And it went well for the boring. For the chamfering I seriously considered cutting it, also because the carb body is very long, hollow, and was only clamped at the bottom. But the tool was sharp and I gave it a go. If you look in the video I didn't let it rub, I was quick to feed, let it cut and retract immediately. I think that if I let it rub it would chatter. I definitely need to get a shorter sleeve though.
Excellent work sir, and a very well made tool, I have worked on a lot of SU carbs and never liked the bent metal shaft couplers, can you replace them with commercially available shaft couplings like Abssac couplings for instance? Phil “Phil whitley, my week this week” on RUclips!
What about a press fit shaft installed with thermal expansion? I would imagine the aluminum carb would expand quicker than the stainless rod so a quick hit with the torch would release it.
When your arbor expands do you get any issues with the sides not being parallel ie. tilted out? I would think with a ~10 inch distance between flange and arbor contact surface that would create quite a bit of play. This is why normally you would use 2 cones screwed on a shaft, one in each flange to keep the inner bore level.
Hi, the challenge with this tool was to make the sides parallel. Have a second look at 20:16. The ring shown is to 'lock' the jaws expanded (so they don't break) while I make the final passes and take the arbor to size. By doing that, I got the sides parallel when the arbor expands to 31.71mm. The end result of this is non-detectable runout and a very repeatable setup. If you look at the comparison done on the surface plate, I got each body parallel within 0.0005" (0.01mm) and that was after removing several times from the arbor to check the progress. That's why I say the setup is repeatable. Of course you can argue that 1 1/4 inches (the bore size) is closer to 31.75mm so there's theorethically another 0.04mm difference, but after averaging the bores with the internal micrometer I found out that 31.70 was actually the bore/arbor size. Hope this makes sense. Thanks
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38minutes of first class machining work passed very quickly, very enjoyable video, thanks
Thanks. Welcome!
I work with cutting edge CNC machines and have access to any tooling I could ever dream of, yet I rarely do works that are as interesting and well thought out as this. You certainly have a vision and a way of achieving the results you're after with the proper means, all with humble machines, and a good mix of home made tooling (and tool!). This is seriously impressive for anyone passionate about restoring carburetors, as well as hobby and professional machinists.
But not only that, the video is filmed with great skill. It is so difficult to film machining because of various reasons, notably lighting of highly contrasted shiny metal parts, chip management, focus, and knowing that you usually can afford one take for each operation. All in all the video has a good pace and excellent sound. I feel like I'm watching This Old Tony again, without the dad jokes. Keep it up man
Thanks for noticing all the hard work and taking the time to write such a nice comment - it truly touched me. 🙂
You say this is like This Old Tony without the Dad jokes, but then he goes and ends the episode like @38:30
@@SolarMillUSA Don't forget the title! - "Let's face it, ..."
@@adamkerz damn, I didn't even catch that. Jedi dad jokes *waves hand*
The problem with CNC machines is that they have a strong tendency to remove the worker from the part. After all, CNC machines have two different jobs. The first is to make lots of the same part as quickly as possible. The other is to make cuts that are not really possible by hand, those very fancy things such as blades for turbines.
The premise that you a running with, of buying obsolete parts well past the end of their life and giving them a freshening-up to make them serviceable again is something every hobby or amateur machinist should be aspiring to. For the people that own those vehicles, that refurbished carb body is worth a lot more than the time you put into it (scarcity being the driving factor) and so you have a nice niche to keep your shop busy and pay your costs while helping others. That's my kind of shop, right there. This kind of out-of-the-box thinking can be just the inspiration someone needs
Thanks! I also enjoy this type of process and the decision making involved to achieve a certain look at the end. Expect to see more of this in channel.
a lot of machining videos on youtube show hobby machinists making a lot of tools, but usually they are making tools so they can make more tools without ever showing them making an end product with their work. It's very gratifying to see shop made tools put to a specific purpose, especially when done so cleverly.
Thank you so much, I really appreciate it.
It depends on what we’re doing. Sometimes I have to make a tool to make a tool, to make a tool. The end result is a tool to allow me to make a part that otherwise is too difficult, or complex to make otherwise. Sometimes I can make a tool to directly make a part. Most of the time I already gave the tools, or I just buy them. RUclips requires people to make a fairly regular series of videos in order to make any real money because viewers want regular videos. So it’s a matter to come up with projects. A lot of people like to see tools being made. So I wouldn’t criticize either way.
Yes very. It's a little disappointing isn't it.
Yep few things are as annoying as making tools to make tools to make something happen/ solve a problem
Yes you buy a lathe and spend ten years improving it. Can't wait to get one 😢😮😅
Reamers only ensure that the hole is to size, location wise they offer no guarantees. Boring bar is the way to go when you need the hole to size and in the right place.
Yes, or you can use an end mill to cut the hole in the right place and round as long as you have an end mill that is not oversize.
True, a single point cutter will do that exact thing. All other tools can be deflected by other parts of the tool.
Lol , a properly spotted and drilled hole can locate a hole within a couple of tenths . The reamer will follow the the drilled hole maintaining the location established by the drill.
@@bobbybishop5662 I wonder why I wasted a hundred grand on a SIP jig borer a few years ago
@@bobbybishop5662 I suppose the pin has to be fitted to the drilled holes?
I don't know how your channel escaped me for so long. I think your mix of tool making plus using said tool is perfect and this good balance might be unmatched on youtube. Thanks for the satisfying content.
Thanks Joel!
I retired 6 years ago as a jig and fixture maker. I liked your video. I just wish I could have had the quality of tooling you have. The people I worked for cried like babies wen I asked for new or different tooling.
I turned a female and a male taper much as you did here and they, as yours did, not match. Instead of remachining like you did, I used a grinding compound and lapped them to one another. The final fit was 100%.
I had the same thought at the end of the video.
That was also my first thought. But it was quicker to just re-cut the angle. Thanks!
@@nbrworks @oh8wingman Thanks! Cutting tapers is always difficult!
@@nbrworks Good choice in general., Lapping tapers is tricky and generally doesn't result in a constant taper, because you can't move the parts axially so you end up with rotational symmetry and matching parts but not cones. Fine if you're making two parts to fit each other and nothing else, but no good for making anything interchangeable.
One thing that can mess you up on male/female tapers fitting properly is the cutting tool has to be precisely on center height wise. Most machinist are trained to run the turning tool just low of center height and a boring bar just a bit high on center. That will make the angle wrong. Some people know this and some do not. Just saying that is something I had to learn the hard way.
Fortunately I was working at a job shop machining a big coupling to fit a tapered shaft so I got paid to do it wrong then got paid to do it right. Cost the boss man a $400 coupling.
Thanks for the mention in the video description. Much appreciated. Nice job on the carbs.
Hi Joe. Your arbor video is awesome. Thank you so much for doing this for us!
Joe's channel is also full of great machining content from nuts and bolts to theory and design.
24:45 This is PERFECT .. the idea that this tool can easily be used 1000 times, and never change accuracy or strength is very awesome!!
In my opinion WELL worth all tis effort, the cost in materials is negligible too!!
not only is that a great tool, but the editing and narration on the video was great as well. I really enjoyed watching it. Thank you!
I was a mechanic in my early life, '60-'92 & spent some time in pergatory working on British & other sports cars. You have found a a way to solve a problem plaguing us back then, premature wear of throttle shafts on down/side draft carbs creating vacuum leaks & 'no win' tune ups, (performance/efficiency is improved w/ new ignition parts, but rough idle, surging or stumbling can't be fixed, so "Your tune up was worthless".
That no win situation caused me to add the extra work of compression tests to all tune ups & reject the candidate if imbalance was found in cylinders. Didn't solve the problems w/ the carb shaft issues & complaints re: "bad tune ups", but it eliminated most of the complaints of "bad tune ups" due to imbalanced compression.
By nearly eliminating the one, dealing w/ the other was easier.
It was still like talking to the wall most of the time, since most customers thought a tune up would solve everything wrong w/ a 125,000 (hard) mile sports car.
Nice work, nice design, clever idea on driving the custom mandrel. I like it enough I may add the drive design to my list of tool upgrade projects. It would be nice to eliminate lathe dogs from mandrel work, if I live long enough to get to it! LOL I laugh in the face of old age & mortality; as long as there's work in my shop, I'll keep going. And... there's ALWAYS work in a shop. ;-)
Very nice work. I once repaired an Obsolete Marvel Schebler carburetor for the engine of my brother’s airplane engine. Was challenging to say the least. I miss making parts for his home built airplanes.When he called me, I knew it was going to be something interesting.
A very thoughtful piece of work holding. If you intend to use the mandrel alot, have you considered drilling a hole at the root of the slits? If you are concerned with fatigue it would be a good idea. Thanks for the video.
Hi, that is a great idea, yes. It was also suggested by another viewer and I will do it. Thank you so much!
Well done! I hope RUclips decides to suggest your channel to more viewers, you deserve it.
Think that a stop drill hole at the end of the expansion slots would reduce the probability of cracking.
That's a good suggestion. Thanks!
That’s what they’re for.
Brilliant machining work, I was holding my breath a few times, but it was needless as it all worked out. Amazing work Sir. Bravo!
Brilliant tool making for a job you felt needed this precision. It looked to me that the castings were very cheaply made for the application. You created a better part that will hold up longer. I hope you price it accordingly.
Wonderful video!
I’m a vintage Volvo enthusiast with far too many su carbs in my shop. I’m just getting going on my machining journey. Really looking forward to your video on the chamber /pot refinishing!
You've done an amazingly beautiful job of both the internal collet and the finished carburettor! ♥
The only reason that I can think of for the brass rod sticking is that I think a bushing and the part passing through it are usually made out of dissimilar metals - e.g. steel and bronze, etc. - it may be that making both from brasses that are similar may cause problems.
I sometimes use adjustable reamers that can be adjusted by maybe c. 200 μm or 8 thou - that lets the reamer be adjusted to get exactly the sort of fit that I want.
I've heard of a soft wood rod or plastic rod being turned to the right size then used with some grinding paste as a hone to very slightly increase the diameter of a reamed hole and give a surface finish which holds lubricating oil.
Thanks Will. That's some good points. thanks! 👍
I would just use some lapping compound. It's kind of a lousy set up, it has to be loose enough to pivot, but not so loose that air can enter the butterfly valve. Seems like it needs an o-ring somewhere.
This is a MUCH better and longer lasting repair than how I would have done it.. Years ago there was an aftermarket company who made these little stuffing box cap things that slid over the shaft and mated tight to the carb body with friction (they kinda looked like a valve stem oil seal). I like your repair much better!
You could also look into the tapered mandrel expanding bushing that is used between centers for turning or grinding bushing OD. You can make a special arbor with threads and a nut to push the bushing into the long taper.
Great work! when setting your compound angle, mount an indicator on the toolpost, square to the workpiece. You can then set your angle based on the travel of the indicator vs. the travel of the compound. For very sensitive angles, this will get you closer than the graduations on the compound can.
If you look closer at my compound you'll see 2 marks 50mm (2 inches) apart, exactly to help with that method 😉
A very sharp well made documentation of a well thought out remedy, for a tricky repair / rebuild. Very enjoyable thank you!
Thanks Mick, glad you liked it.
A tip: Loctite does not like zinc. If I end up with galvanized or Zink plated bolts Etc. I soak them in vinegar, which will dissolve the coating, then steel brush to remove the "Rust" from the vinegar.
Suspect part was rotated on angle plate and realigned for each bushing hole from the quill.
A dividing head or rotary table required to achieve perfect alignment of the holes. ( you have an engine lathe and a knee mill, could build one. )
Side notes, Red Seal trade school hints from Canada:
Hand hone rads on the corners of the cutting lip to lands on twist drill when the chisel point has no material to keep it centered, cuts smooth acting like a reamer.
Blueing should never be smeared on full periphery, 3 equally spaced thin lines on taper angle and the mating part is twisted 1/4 turn max.
Thanks!!
Really enjoyed.
Thanks for taking the time to make the video and share it...
If you bolt down the carburetor flange with the sticky shaft, does the sticky go away?
Just a thought. I know with the aluminum LS block, the crankshaft is sticky until heads are bolted on.
Great Video. I once dreamt of restoring vintage carburetors and now with a mill and a lathe you make me rethink having thunked it. Thank you
Hey, glad to have you motivated again. I haven't tried bolting down the carb with the sticky shaft.
I have a box of different expanding arbors one set will chuck up in lathe Jaws or a collet, the other end a cap screw, they expand parallel, bought this set in the 80's, don't know if anybody still makes them.
37:47 What you might be seeing is the rigidity of your setup or machine. The Z-axis tool pressure may be deflecting your table, combine any other variable and it can easily add up to this amount. Try measuring the movement of your mill table when locked down with an indicator. If your machine is deflecting or twisting it can cause unpredicted tolerance issues. Then, as usual, make sure your mil head is trammed in. Great video and ideas!
I have a very old Tillotson book from the 40-50's, they made special piloted style reamers and bushings for reworking throttle shaft bores. Too bad there isn't anything like the today. Believe it was setup so you ream short of the venturi to keep that surface round.
I’m only partway through the video and I’m already seeing a lot of old-school techniques here. Many things were bored, turned machine in what would now be considered oddball ways back in the day. Your idea of using a ring on your expanding arbor is spot on. One thing to remember about turningmaterial that has been cut into segments is centrifugal force is pushing the pieces outward as you are trying to machine them. If you’re not able to use a ring to hold everything together, you may have to run slower RPM and take multiple cuts.
Can you imagine the cost of what you just did, if you were charging for a one off part restoration?
E.g., I just restored an old Minolta camera, it took me 25 hours to complete and for that I didn't need to make any parts. The camera cost me £23, the best price I'd get for it would be around £100, so at a modest charge rate of £25 / hour, that would be £625, that's £525 more than the camera is worth.
Setting up to establish and maintain a datum plane or axis is always worth it, but it takes time and forethought. Your process is solid.
you would get fairly more accurate hole positions for the rebushing operation by using an endmill for the first hole opening, after that using drill might be okay, but in essence endmill evn held in a 3 jaw drill chuck tends to produce more accurate positions even when the spindle/quill rigidity is compromised due to wear on the machine. in general, long spiralflute HSS drills tend to wonder towards the center of the already present hole as that position results in the most balanced cutting action on the two edges of the drill while the body is relatively flexible, while endmills just dont. behave like this, they are totally fine with going in off of center of the existing hole.
In this case, since the hole was finished with the boring head, it didn't made difference to start off with a drill.
Nice job.
No reamer, is adequate for straightening a hole.
Mandrels sre awesome.
I would have bought a cheap expanding mandrel.
Your way worked just fine
Hi NBR, first time here, great to see you working so clean and precise. With interesting explanation and approach to all the aspects and problems of the job. Great video work also. Many thanks!
Just one point . . . it would be nice I think to have some drawings or at least sketches, to follow along.
Thanks, I'll have that in mind.
Awesome. Not really applicable probably since most people don’t have one on hand, but jig grinding these two bores would be the way to go to get them dead on in line with one another. I ran a Moore No. 2 at one point and super precise hole, slot, etc. location size and alignment were its specialty. Thanks again very glad to have stumbled onto your channel
I've done this methodology many times, usually I make a mandrill. Nice job 👍👍👍
Use an adjustable reamer with a guide pin to finish the bores of your bushes from either side. That will correct your out of alignment issue. A reamer will only follow an existing hole, and your extra long reamer almost certainly deflected slightly to do the second hole.
Machining of carb flanges quite common in my workshop...have done Weber's, and other carbs, furl pump flanges etc etc, It works.
Another excellent episode!
But.....what car is going to get those carbs????
Nice job! A very novel idea to fix a very real and common problem...I'm not a machinist but just retired and I hope to
get a mill/drill very soon and I anticipate learning a lot from you...I've watched a few of your videos and like what I see!
I imagine the reamer did deflect, when you where talking about at the end of the video. Have you ever put an indicator on the end end of the reamer while it’s chucked up in the spindle and touch it with your finger ?It’s amazing how much long tools can deflect and with such little force.
you can def do this in a mill. you use something like a mitee bite ID expansion clamp. which is essentially the tool you made...but the mitee bites are flat on the bottom. for holding round parts in a mill :)
I didn't know these clamps, thank you so much for sharing!
instead of a dog bone, you went for the "In the Dog House" metaphor. Very neat seeing your build process. Thanks
Really surprising how much difference there is between the castings as they should be pretty similar.
Both bodies were not originally a set, I'm pretty sure I have mixed up some parts looking for the best ones to make 'my set'. But looking at them I wouldn't say they had 0.5mm (actually more) of difference. Some of these bodies don't have a take off for the distributor vacuum and others don't have a way to mount the choke lever cam, that's why I mixed and matched until I got what I need. Thanks!
This is the best thing I've seen in a looong time!
As a beginner, (just a few, cancer interrupted years ago), I wondered & asked if angle of contact of the insert & the material made a difference. Didn't get, or find an answer, so just kept on w/ getting a working contact within the size limits of my hot rod Sherline, (too little tailstock extension, no compound, tooling & toolpost a bit too large).
A few more years into learning, some new tooling & I'm discovering the angle CAN make a difference.
In situations where you're getting ling curly swarf, try changing the angle of the tooling.
My theory is the cut coming off the material is missing a portion of the insert which will change the path of the swarf & cause it to break.
This also depends on the design of the insert's chipbreaker; some it won't matter.
Be curious to hear your results if you play around w/ this.
Turning a cone slightly under or over center will change the angle. ID is the hardest.
Awsome video, thanks for taking the time to share this
That was some nice machining, parts turned out well, far better than the original manufacturer ever considered possible.
I am a little surprised you didn't radius all the internal sharp edges while you were in there with flex shaft grinder?
Back in the day it was much more common to have sheet of emery paper on a flat surface to correct bow on flanges, exactly how you did it.
Milling machines were a 'luxury' few shops had and cost at machine shops was far too high for majority of people.
There were aftermarket kits for the bushings, just drill them out and hammer them in (then spend time with a file and emery cloth fixing the burrs).
I imagine they have been out of production for 50 years or more by now though?
You should have drilled holes at end of expansion slots, it would mean there is less material to flex. You could still do it but will need to use a center cutting end mill.
Using Morse taper adapter as an extension for center may give more clearance but it's going to be very flexible when you have any side loads (as in turning) and probably reason for chatter? All in all, a very interesting video.
Are you (or have you) done a video on rebuilding the SU carbs? I had them on my first car (1966 Rover)
Hi, nice to have you back!
I might add some small radius in certain points, but I want to do it carefully and focused, not in an awkward position with the camera in the way.
I believe Burlen in the UK still sells service kits. I have one I bought several years ago, it came with steel bushings, coated with teflon inside, but in my point of view, they leave a little bit too much play for the shafts. That's why I didn't use them. I also believe Burlen replaces them, as in a service they provide, but I don't know details about that.
Regarding the holes at the end of the expansion slots, I will do them, like you say, plunging a center cutting endmill, this was also suggested by other viewers (thank you).
The morse taper extension... it's a good point. I bought the extension because I needed the clearance, but I also thought it was going to flex a lot and be unreliable (or reliably give bad results). But in fact, I can't complain. At 2:02 there's an example of that. Until something changes, I'd say that extention is working for me. At least it's better than having the tailstock fully extended 😉
Video with the full rebuild of the carbs... no, I haven't done that yet. I still need to take care of some things first: pistons and chambers, choke mechanism (I need to invent something to make it work), take care of the manifold, air filters, etc. But I'll make that video, that's guaranteed.
Thanks!
You are correct: a reamer will tend to follow a drilled hole. Very interesting video. What make and model of lathe is that?
Love the quality and thought put into your machining. Its great to see some decent but appropriate size cuts taken on a lathe.
Also given your results you have adjusted it perfectly so while not an expensive lathe you are getting everything out of it you can.
By the look of the chips you could up the feed a little or the speed to help get the chips to break up.
On a more important note 6 jaw chucks are for holding thin wall workpieces. They help lessen the amount of distortion.
On anything else you can't be sure that you actually have the 6 jaws working - only 3 of them may be (think of stools chairs etc.) depending on the workpiece.
So it is best to use a 3 jaw for most work - though it doesn't look anywhere near as cool.
Hi in the racing game a little goes a long way, heat expansion, long time corrosion from fuel,s ,what you are achieving helpes me a long way, thank you for your time in making this video, cheers mate 👍
No problem, glad you found it useful. Chambers and pistons will follow one of these days (also with modifications).
RUclips/Google recommendations is magic. I just finished a expanding mandrel today. I have not searched for anything regarding expanding mandrels (just made it from my own idea in my head). And then i get home and is recommended this video the same day...
They're watching you 😄
Really enjoyable vid. Thanks for your time to make it.
"Let's face it..."
I see what you did there.
Fantastic video mate. Good pace, good information, just all 'round worth watching. Well done!
Thanks!
Maybe I missed something, but wouldn’t it be safer to cut the expansion slots last? I was so nervous watching it turn on the lathe with those slots, expecting the cutter to grab the piece and shred it.
As other's have probably pointed out, the reamer is not necessarily going to correct the bore alignment, a boring bar is the best way. Maybe bore/bush one side, flip it and then run a ground shaft up through it and indicate off that shaft, then bore the other side. You could also set up a mini line-bore arrangement on the lathe. I'm sure there are other ways as well.
This is art work.
And well done on a completed project with excellent results.
Again a coupe of comments (I left some in the butterfly spindles video).
Why not use ball bearings on the spindles? Weber does it, Dellorto does it, I am sure others too. Technology has come a long way and we now have pretty much any size and flavour you want. Have a look at hobby (radio control) shops and see the diversity of sealed bearings in any size you can dream up they offer these days for not much coin. I have used them in carburettors for a while now with great success. No more shaft wear, no more bore wear and much better sealing and reliable positioning than you can ever dream to achieve with metal on metal running clearances. Not to mention smoother turning. In your case all you have to do is add a counterbore to the outside of the spindle bore on either end to house the bearings and threads to the spindle ends. If space does not allow for a very large bearing, just make the bore deeper (I have noticed the bores are quite deep) and put two bearings back to back on either side. Either way, in a carby these bearings won't see the loads they are designed for so they're basically in there for life.
You, sir, are a real man of genius. Thank you for sharing.
I make a lot of mandrells as well, far simpler, just to support the bore of carburettor bodies. There is always a side bore in the body, at that location I make a threaded sidehole in the mandrel mostly M5 or M6 and secure the carburettor body from sliding of by using a bolt and washer . the carburettor body must be in line but is allowed to be eccentric so any surface that needs to be flat is perpendiculat to the axis but the cutting grooves to flatten the surface do not need to be concentric with the internal body bore . pistons alike if they need a new circlip ( retaining the piston pin ) groove
we need more content like this on youtube! I liked commented and subbed! Keep up the excellent work!
Hi Daniel, welcome and thanks for the support!
If you don't mind the suggestion, I think that you could probably have put less stress on the expanding mandrel if you reduced that cone angle to about 5°relative to centerline. The one you have there looks like it's about 30°relative to centerline. You don't have to expand it very much in order to get a tight fit.
Regardless, I think you did an exceptionally good job in devising that tool..... And I'm happy it worked out for you! 😄
Thank you for a very informative video however, the one question I have to ask is what fuel will you be running the engine on that will pass through the carb? If it has an ethanol component, the brass bushes and spindle will corrode and cause all the same type of issues that you are attempting to machine out. I would use a Delrin bush and a stainless or silver steel spindle that can be bought in certified diameters. Its interesting to note that the Brazilian Solex carbs have next to no brass components because their fuel either contains high volumes of ethanol or neat ethanol.
Hi Clive. That's a very interesting question. I've seen the concern online before. I remember reading a thread in some forum where someone tested some materials in some jars with ethanol... as far as I remember it was not conclusive if it would cause a problem or how long it would take to cause that problem. My first concern is the float bowls which are thin brass and are in constant contact with fuel. Currently I can still get (supposedly) ethanol free fuel, but I don't for how long it will last.
Do you have something or a situation you'd like to share about this? I'm interested to know more. I'm aware I need to get good rubber hoses (Gates maybe) and even with those not expect them to last more than a couple of years.
@@nbrworks The issue with ethanol is a common one that is well known in the classic car world. I have seen various renovations documented where the brass components of carbs have corroded, which is unusual to say the least, usually the brass elements last considerably longer than the other metals around it. These examples were based in US where eithanol has been used for some time and the machines were left for long periods with fuel in them. We are talking prolonged periods so that testing would have to extend over years and not a few weeks.
I have an aircooled VW Beetle with an electronic fuel pump that was initially an old faithful that I purchased many years ago before ethanol was added to fuel. It served reliably in various vehicles, including the Beetle until ethanol was added to unleaded and it expired not too long after. The replacement pump is identical although, Facet the manufacturer, specifically states that it is suitable for ethanol added fuel. It might be a coincidence that the original one failed but the timing was noticeable. Also the Beetle is fitted with a Brosol carb (Brazilian Solex) that has fewer brass parts than the original Solex carb and given that Brazil has a high usage of ethanol, I would expect that is the driver for the change.
If you are changing rubber hoses then the safe ethanol resistant quality is R9. Unfortunately, R6 is commonplace that is slightly resistant and that is what you will mostly find in the motor factors. The brand is not so important as getting the correct spec SAEJ30R9, which will be printed on the hose.
The other issue with ethanol fuel is the longevity, with E10 'going off' within 2 months, E5 within 6 months and non=ethanol fuel lasting 12-18 months, which is important for classic car owners and horticultural machines that may stand for long periods without use and a fuel supply can sit in a can for months.
Gaskets are usually expected to make up the difference in minor defects, and warpage is to be expected from being "handtightened" over and again. Eventually you will run into a leak that cannot be solved with more wrench or the application cannot risk liquid gasket maker seeping into the orifice. That is definitely when you need to consider surfacing like this
What kind of steel is that you’re working with? It seems to cut like butter 😍
Hi Edward, it's free machining steel. ISO 11SMnPb37 / AISI 12L14. Thanks
Basically 1018 with more sulphur and lead to increase machinability.
Very nice work in any case. Looks great
Aw man, a proper SU crate O.o SU's are still made up the road from me in Salisbury in Wiltshire and also cover Zeniths, Solex and other brands of vintage carbs. Do love old vintage crates and wooden boxes for putting stuff into, just adds a bit of gravitas to your stuff in my opinions :D
Yes, the crate must be really old, but still in great shape!
Great demonstration how accurate you have to make *everything* to get the throttle body axle to stay within 0.1 mm accurate to parallel.
Very nice. Some years ago I did a similar carb refurbishment job, but in my case I made the arbour to a shrink fit. Heat the carb in boiling water, push it in place, machine, then heat both the carb and the arbour to 150°C and they released perfectly. If I were to do the job again, I'd make the arbour to a slip fit and glue the carb in place with CA, releasing with acetone or some heat. Not as elegant as your solution of course.
I think you need to use a machinist jack to support your part while reaming to improve the straightness of the holes.
Way too complex. Not the way I would have done any of this. I would have simply purchased a hardened 1.250" diameter mandrel with an R8 collet shank. However, it worked and produced the dimensions you desired, and should be repeatable in future use.. Maybe lap in that sticky shaft, although you will never feel it with the pedal against the return spring setup. For the best possible seal you could have added O ring pockets or grooves on each side of the shafts.
Very nice presentation!
My only other comment is brazed carbide and high speed tooling in general has less tool pressure
JIM ❤
Impressive work and very nice video to watch and listen to.
Regarding the pairing of materials, am I correct in assuming that bushing and shaft are of the same material (=brass)? That would lead to a higher wear rate than pairing dissimilar metals. I'm used to seeing steel shafts running brass bushings or in absence of those, in the aluminium of the throttle body itself.
Hi. The bushings are bronze and the shaft is brass. Just like the originals.
Great work :) , not being an engineer by trade you learn pretty quick its not the tools that cost but having the correct measurement tools so you can actually do stuff and then its endless if you have the skills (and the right lathe ofcourse) - Keep up the great work
Thanks!
The chipbreaker is not working because you are feeding it to slow.
Thanks, nice video. Sold all my equipment & miss making chips.
The reamer can and will not fix if the bushings are off axis or off center to each other - remember its a reamer not a endmill, it will follow the bore no matter how off they are, as long as it can bend as far as it needs to.. if you're getting uneven pressure from the lower hole, because its off center or off axis from the top hole, the reamer will create a hole with a notch in it form bending, or it might even get oval, even worse it will be different along the length of the hole - the top might be bigger to the left side and going down it'll get bigger to the right side of the hole.
Thats exactly the reason why it isn't recommended to use a reamer in that way, unless you're absolutely sure the holes are perfeclty in line with each other.
Nice work, really nice attention to detail 👍🏻
spray some water under your sandpaper to keep the edges down while trying to geet parts flat!!
Thanks for the tip! (don't tell anyone, that was the bathroom scale 😄)
This is fantastic, many thumbs up. Chinese lathe (that's what I'm looking at for a size upgrade from my most excellent but too small Sherline)? What brand? Which model? It looks like you have personally tricked it out to the n'th degree. Any information would be most welcome, thank you.
Hi there. I have a rebuild series of the lathe, you can check my older videos. The lathe is from HBM Machines, it's the equivalent of the Precision Matthews PM-1022V, if you are in the US. I haven't scraped it, I just carefully rebuilt it with minor changes. I'm working on a related post that I'll publish on my website soon.
wonderful. Thanks for posting.
Not sure I would have done the partial bushing, you dont want that remaining bit becoming loose over time and maybe falling into the carb and wedging the throttle open or affecting AFR due to blockage in the inlet.
The ring left is part of the carburetor casting - it's aluminum. There's no way it will become loose. Sure in theory it could break in pieces - but I don't see how that could happen - there are no forces making that happen - it's just highly unlikely.
@@nbrworks Ah! I thought it was part of the bushing you'd left rather than the housing.
Great video I really enjoyed watching your skills.
No, no, the old bushing was completely removed and the new one will be stuck between that aluminum shoulder and a clamp that bolts onto the shaft (not shown in the video). Worst case it gets loose and rotates, but it will not come off. Thanks (glad you got it with my explanation).
31:24 I wonder if an 'oldham coupling' would be a good choice for this, unless it needs the 'give' and spring the metal can provide. But it just seems more built to cost. Also modern day 'spring couplings' like those used in 3d printers could have those properties and likely better concentricity.
Yes, there are better functional choices, but something I didn't mention in the video was 'looks'. Being for a classic car, I'm trying to keep these carburetors 'in period'. That actually influences a lot of decisions. Thanks!
Love the Saran Wrap on the mill, great idea, thanks.
It is absolutely amazing, the ingenuity machinists use to constantly improve the quality of their work. Now if I could convince the garbage collector to adopt such a strategy to find ways to do less damage to my cans.
drill and tap pipe thread npt spit twice with band saw a pipe plug will expand the arbor
He sounds like a guy that's probably in a place that uses a lot of metric and British straight. British taper would probably be more common in EU than NPT. But I wouldn't know as I have never had to plumb in Europe 🤣
But taper threads definitely sounds like a better idea if he's not running an expander plug with a matched angle. Less work involved, off the shelf replacement parts.
great work again, thank you very much! 👍 why did you use such a long boring head to bore the bronce bushings and the chamfers...i would be afraid of chatter...although they came out great, so what : )
Hi, nice to have you back!
It was a matter of using what I have available. The boring head takes 12mm tools.
I don't think I have any broken tools with 12mm shanks (to grind), and the 6mm boring bar shown at 8:16 looked perfect for the job, including the 12mm sleeve (coincidence?).
I thought of cutting it in half, but not without trying it first. And it went well for the boring.
For the chamfering I seriously considered cutting it, also because the carb body is very long, hollow, and was only clamped at the bottom.
But the tool was sharp and I gave it a go. If you look in the video I didn't let it rub, I was quick to feed, let it cut and retract immediately. I think that if I let it rub it would chatter.
I definitely need to get a shorter sleeve though.
@@nbrworks thank you for the answer 👍 i think you are right, the quick retract was the key. nice to see, that it worked out : )
i need to adjust the diameter manually in thousands of a millimeter to keep an h tolerance past 5 centimeter on a nc lathe at work ...
Amazing work sir!
What instrument did you use for making the chamfer tool? amazing setup to alligne in any direction!
Hi, it's a deckel tool grinder clone. Look up for 'u3 universal grinder' on Google and you'll find it.
Faces being square to the bore matters how with a carby? As long as they are flat they will seal and the fuel will still flow. What am i missing here?
Great Work and nicely presented!
I very much enjoyed your machining content.👍 Liked and Subscribed.
Welcome Dariush!
Excellent job, a master.
Excellent work sir, and a very well made tool, I have worked on a lot of SU carbs and never liked the bent metal shaft couplers, can you replace them with commercially available shaft couplings like Abssac couplings for instance?
Phil
“Phil whitley, my week this week” on RUclips!
Hi Phil. Yes, I could replace them, but I'm looking for that authentic/period look. That's why I'm keeping them 😉
What about a press fit shaft installed with thermal expansion? I would imagine the aluminum carb would expand quicker than the stainless rod so a quick hit with the torch would release it.
When your arbor expands do you get any issues with the sides not being parallel ie. tilted out? I would think with a ~10 inch distance between flange and arbor contact surface that would create quite a bit of play. This is why normally you would use 2 cones screwed on a shaft, one in each flange to keep the inner bore level.
Hi, the challenge with this tool was to make the sides parallel.
Have a second look at 20:16. The ring shown is to 'lock' the jaws expanded (so they don't break) while I make the final passes and take the arbor to size. By doing that, I got the sides parallel when the arbor expands to 31.71mm. The end result of this is non-detectable runout and a very repeatable setup.
If you look at the comparison done on the surface plate, I got each body parallel within 0.0005" (0.01mm) and that was after removing several times from the arbor to check the progress. That's why I say the setup is repeatable.
Of course you can argue that 1 1/4 inches (the bore size) is closer to 31.75mm so there's theorethically another 0.04mm difference, but after averaging the bores with the internal micrometer I found out that 31.70 was actually the bore/arbor size.
Hope this makes sense. Thanks
Great video
Kimber