Great video Tom! Here's a trick I learned from an old German toolmaker: rather than sneak up on a size, when I want to turn to a +/- 0.0002 tolerance, I snug up lightly on the the ways for cross slide and carriage, and lock down the compound. If I'm turning common-as-dirt 1018 cold roll, I normally use carbide inserts, but to keep with your example, using a HSS tool I would crank the rpms up so the SFM is 135 ft per min., or ~435 to 450 rpm for 1-1/8 stock and a target of 1.0000". I'd use a sharp tool with a nose radius of 0.016 to 0.018, and feed at 0.002" to 0.004" per rev depending on the desired surface finish.. As you show, its very important to get the tool on center. Then take a "skim cut", as you did, but turn across the full width of the part. Let the part cool if needed ( or run coolant), and mic it. Let's say it mic'd 1.1083". Set a dial indicator to pickup the cross slide movement & zero the indicator. Next subtract target dimension from the skim cut diameter ( 1.1083 - 1.0000 = 0.1083) Divide this amount by any whole number that will give a result that is equal to or slightly larger than the tool's nose radius. For example, 0.1083 / 6 = ~0.018" and a close enough match for our tool nose R.. This gives us the depth of cut ( radius to dial in for the first of 6/2 or 3 passes. This cut should mic at 1.1083 - 0.036" = 1.0723. Let the work cool if needed and mic it. Lets say it mics 1.0731. Subtract our target (1.0731-1.0000 = 0.0731. Divide by the number of remaining passes (2) = ~ 0.0366", Divide by this amount by 2 and dial in this DOC, This pass should mic 1.0731 - 0.0366 = 1.0365. Let the part cool, mic it. Let's say is mikes 1.0368. Repeat the process, in this case 1.0368 - 1.0000 = 0.0368. Divide by 2 and dial in the DOC for this last pass. Let the part cool in needed, and mic it. You'll be within 1 to 2 tenths, if not dead on size. The math may seem complex here, but it can readily be done in ones head once you understand the process. This works because it reduces tool nose pressure ( by taking a cut that is equal to or greater than the nose radius) and by compensating and adjusting for any residual pressure or part flex over nearly consistent tool pass pararmeters. Give it a try - it really works - and especially when boring an ID. Google "Sanvik 3 Pass Method" for better how-to info on boring a close tolerance hole using this method. (By the way, the method I described here works on my newest CNC lathe, as well as my 43 year old 15" Clausing, my old pre-WW11 Southbend, and my little Chinese wonder from Enco :-) Accuracy is 99% machinist technique, and 1% machine :-) Thanks again for the great videos!
Thanks Ed, I haven't heard of that technique before, but it does make sense. Not sure I understand the need for all the math gyrations though. The object seems to be to limit the depth of cut to the radius of the tool to reduce part flex and heat , so why not just take a cut and divide the remainder by 2X the tool radius to get the required number and depth of cuts? Tom
Tom, I just want to personally tell you thank you. All that you did, to help us beginners out, I can speak for myself here; gratitude! I hope you can hear it personally. Your time/kindness will never be forgotten. Thank you Brother. --Joe
Wow, these videos are amazing. A rare combination of expertise on the subject, great teaching, and quality camera work. I usually find videos to help me accomplish a specific task, but I am watching these for fun like a football game. Other good resources I have used to learn machining and fabrication skills are Machine Shop Essentials, Questions and Answers by Frank Marlow, and my favorite book on the subject, Metalworking, Sink or Swim by Tom Lipton. He has some very funny stories in addition to sharing his tips and tricks he learned over a career as a metal worker. I never got the chance to take metal working classes in high school, but it feels like I have the best shop teacher in the world now. Thanks, Tom!
I'm a qualified fitter and turner and I love doing anything on the lathe and milling machine. I love to see videos like this out there to teach the younger generation. To the 23 that disliked the video, I think they must be some sort of dress makers. LOL. Thank you sir for the teaching.
Thanks, and I wholeheartedly agree. I plan on doing a lot more on the basics once I get back into making videos. Right now I'm working on learning how to function with this new retirement thing. :) Tom
Thanks Tom For us beginners your detailed discussion and excellent filming is really very helpful I look forward to seeing your other vids in the future.
Great videos. Thank you for sharing your knowledge. Took your advice from the 'parting video' and ordered a quick change tool post. 1955 9 inch Southbend...worn out, but we get by.
That was great advice Tom, I have been struggling with getting accuracy from my dials. I discovered one thing of importance, I had movement in the dial after I took the back lash out. I pulled the rod and shoe and couldn't see anything wrong. I have a 1960 13" South Bend Lathe. The screw head is slotted so I took a screw driver and tightened it. This did what it should be doing, no extra movement other than back lash. Thanks so much for the lesson and advice.
Such fantastic videos! I've been watching for hours and see no end in sight! I have learned more today watching your series of videos than I have in all of my other "Youtubing" and reading! your teaching style speaks well to how I learn! I am getting very excited to apply all of my new found knowledge on the lathe! Very excited!!! Thank you!
Thanks for your videos Tom - as a 'noobie' I am enjoying watching all of them. My Hardinge HLV arrives in early January and most of the people I have spoken to regarding tooling have pretty much insisted that carbide inserts are the way to go - however I am buying a bunch of HSS blanks and a decent grinder and will also try and teach myself how to grind my own - your videos have been helpful All the best Pete
This is how I do it on parts that must not be scrapped (large price tag): after roughing I run spring pass to remove any material that was left by roughing tool deflection, then I measure the part. I may take light semi-finishing pass to leave myself desired amount of material for finishing pass.I stop the machine, and cool the part down with coolant running for a few minutes. I then measure the part, move tool to finishing diameter ,and run the pass for the length of 0.25" then stop the machine ( I do not let tool run to the end yet !) I measure the part to make sure size is ok, then continue the pass. Sometimes there will be a witness mark where the tool was stopped so I polish that off at the end. If I measured that the part was undersize, I adjust, and only that first 0.25" will be undersize ( hopefully the customer will forgive:). Imagine that you let the tool run to the end because you trusted your machine ,just to find out that you are 0.001" under for the entire length!
Tom, thanks for the videos! I watched them as they came out, but since I recently got a 1955 South Bend 9" lathe I'm watching them again. Actually being able to try what you are showing is different from just watching...and tells me what I need to see again. I hope all is well with you and yours. -- Mike
Thanks Mike. Now that the weather is turning cold, I'm getting geared up for another round of videos. A Shure wireless mic that I won on eBay showed up in the mail today and hopefully it will improve the sound quality in my videos. I'm actually in town this weekend for the first time in a month, so maybe I'll get a chance to try it out. South Bend makes a nice for light machining. It should serve you well. Tom
It's always fun to get new tools, whether mics or lathes. The South Bend is a small lathe, but I'm only making small things for now, so that's fine. It's in good shape (only two prior owners, both hobbyists who took good care of it), and it came with a bunch of accessories, including a milling attachment and a lever-operated turret tailstock (in addition to the normal kind). No 3-Jaw, but it does have a 4-jaw and a collet chuck, so no limitation there except on speed of chucking. I turned and milled the T-nut for a QCTP ok, and I'm making a few other small tools and add-ons...so far so good thanks to your videos and some others I've watched. Without that I'd still be wondering how to make it go! I'll be downloading your toolbit grinding PDFs next...just received some blanks I ordered. Thank you for the help! -- Mike B.
Hi Tom.... Nice chips! Reverse counting always confuses me, but I guess it is just a mindset and I need to push myself to practice and change my methods. I watch my in shop mentor, a retired tool maker, use this method all the time! Happy Holidays! Really enjoy your lessons! Chuck
The Imperial system isn't complicated at all if that's what you are used to. First thing most shops do here if they receive a Metric drawing is convert the dimensions to inches. By the way, I understand you guys still use a number of Imperial measurements as well, so maybe the Metric system isn't all it's cracked up to be. ;)
Imperial isn't complicated, but the tendency for micrometers to measure in thou (or smaller) is a bugger when many sizes are in x/8, x/16, x/32, etc. You can convert with tables or calculate them on the fly, but it's an unnecessary step that is prone to introducing errors.
Hi Tom, another good video, not necessarily the way I do it, but when asked I can confidently recommend your channel to beginners as a good place to start as your videos are clear, concise and to the point and without dogma, unlike certain beginner orientated channels. Re dia/ rad cross slide dials, the convention this side of the pond is that Imp lathes are Rad and Metric ones are Dia, not a hard and fast rule just convention. ATB chris
Thanks Chris. I don't think that applies over here. Most of the industrial lathes I've used read diameter on the cross slide and radius on the compound. One exception are the older South Bend lathes. I seem to remember some of them read the radius on the cross slide. Tom
Yes it takes a lot of selflessness attitude to educate the masses to put up video's and expose yourself to trolls, good on you for making the time to keep machining alive, ignore the snowflakes that like to leave a thumbs down.
Tom I have been watching your videos for quite some time. After several of your lathe series I have become interested in what kind of lathe you have. It has some features that really interest me. Thanks for all the effort you put into your videos! Keith Mifflin
Keith, My lathe is a Hardinge HLV-H Toolroom lathe. I bought it new in the mid eighties and in my opinion, it's the best lathe available for the one off type of work I do. Unfortunately, they are no longer in production, but there are copies and quite a few used ones around. Tom
Thanks Tom! Oh that hurts when you are in a class where none of the students know what they are doing....one minute its there and the next its gone! But now I get it....find out the diameter you need; find out how much you need to take off to achieve that diameter; zero the diameter you have; and take off the amount you need to achieve your final diameter. Hopefully I will never forget again! Oi! CAT
G'day Tom just subscribed thank you for your easy to follow videos, really helps a lot when you are starting out. One video which I am interested in was grinding your own cutting tools as I would prefer to do this myself. Thank you kind regards John Tasmania Australia
Sorry Bill but I'm not a fan of carbide inserts on light machinery. HSS will produce a better finish, is more forgiving, more flexible, more economical and all in all a much better option for the home machinist. Tom
Tom's Techniques There are HSS inserts out there as well, Dear Tom. Maybe you could make a video on those? If you have them on hand, of course. I know Arthur Warner Co. makes HSS inserts. Made in USA! ;)
Nice video. I found it a bit ironic when you mentioned to be careful to not move the cross slide crank at 7:47 on the video considering that you did accidentally move the crank between 7:34 and 7:40. Although to be fair, I don't know if the movement was within the slack that causes backlash or not. But in any case, the crank is visibly moved a few degrees.
Thanks for pointing that out. You might also notice that when I took the trial cut after setting the dial, I realized the error at 10:20 and was able to correct it before taking the finish cut. All machinists make mistakes, the good ones recover from them before they become permanent. Tom
Thanks for another video, Tom. On my Hardinge HC, I'm unable to lock down the hand wheel to set my dial. For now, I've been holding the wheel, and adjusting the dial. I see you have a little set screw on your machine. The only manual I have is online, and for an HC, which doesn't cover locking the hand hweel down. I'd appreciate any quick pointers you could give. Thanks again.
Thanks Aaron. I'm not familiar with the HC, but it doesn't look like the cross slide dial is the same as mine. There might be a spring inside to provide friction and let you set it by holding the crank. Tom
Very nice..... Just so e food for thought. Could you show us how to drill really really super small holes that are accurate and won't break off your drill bit..... Also... Cover how to best use reamer's.
The trick with small drills is an insanely high rpm. A 1/16" drill for instance, should be spun at 6500 rpm to prevent. Any small drill like that should also be spotted with a center drill to help it start on location. A video on reamers is a good idea, I'll add it to the list. Thanks for the comments and the suggestion. Tom
Cool thanks. I have to turn down to a shoulder so I will try rotating the bit some. You mentioned making another tool with no side angle so I assume it would look like a facing bit? Except perhaps you keep the angle at 90 vs. 70 is what I would think but don't really know. Anyways cool vid. The reverse count threw me for a loop but that's pretty cool after I understood that.
I also see you mention casting here and there.....I actually built the Gingery charcoal furnace but I haven't got past melting down engine blocks and making ingots yet. I was going to make the lathe but decided id rather go straight to making stuff I need rather than go that route. Time is a big factor. Being a sheetmetal worker for 15years this has opened up a whole new level of fabrication for me and I am frustrated on a daily basis that I never learned this stuff a long time ago.
Hey Tom, love the videos. Im a welder fabricator by trade, but love to machine parts up at work after hours, Ive been having a problem when I'm turning long parts to diameter. I turned a part that was 18-1/2" long and 1-1/4" down to 1-1/8" and I was 0.015" off from one end to the other. It hasn't been a big problem so far, but I would love to know how to get ride of that slop in the part. Thanks again
You need to use a steady rest or follower rest for parts that long to keep the center, unsupported section of the part from pushing away from the tool. Tom
If you had the work supported at the tailstock, with a live center and the part was different diameters at each end, you need to adjust the tailstock so it is indeed centered on the chuck. The center of the part will also be different if you don't do as Tom suggested. The tool will push the work away, essentially taking less of a cut than you think it just took.
Hey whats up Tom good video. I skipped a small portion of the video so I am not 100% sure if you did or not say it but I was wondering if you mentioned that when you add on a diameter with the dial that you are actually doubling what you are cutting? I have never operated a retail lathe I have a homemade lathe so I am not sure if the dial accounts for that. Basically when one cuts on a diameter with a lathe they have to advance half the amount of the total difference because if you set it to 5 thousandths you are really taking off 10 thousandths of the total diameter since 5 thousandths is being removed all around and both measuring points. I apologize if I missed this or I am misunderstanding something here. Take care...
+Micscience On most lathes, the cross feed dial reads diameter directly. In other words, if you move the dial .010" then the diameter will be reduced by .010". The dial on the compound does not compensate. It moves the tool whatever the dial says. Thanks for watching. Tom
Understood; and a well explained video. As always, thanks’ for taking the time to make this video! And I support this site. ~M~ PS: this may be my “tagline” until I have a question?
Would you not instruct that when setting up your work that you first check the chuck clearance by moving the spindle by hand and then move the X and Y axis to check if the chuck will strike the bit holder or the bit when the holder is close to the chuck? Thumbs up.
Hi Tom, I really enjoy your videos and have found them really instructional. I am a complete novice so please excuse my questions if they seem simplistic. When you did the facing video you rough cut outside to centre and then finished centre to outside. In this turning to dia video you went longtitudinally from the tailstock end on each cut, including the finishing cut. I was just wondering if the reason was because it was because of the way the tool was ground. Many thanks, Gordon
+Gordon Agent Hi Gordon, You will always get a better finish facing while feeding from the center out because of the shallow angle of the side cutting edge. You may or may not get a better finish that way when turning, depending on the material. In this case, the material was leaded steel so I got a nice finish on the first cut, and didn't need to take a finish cut left to right. Machining is all about making judgements based on results and the only way to learn how to do that is through experience. Tom
Good video as usual. One question about returning the cutting tool to the start position. Do you always retract the tool from the work when you return the tool to take another cut? I have noticed when I return the tool to the start position without retracting, it still cuts. Can you tell me why that is?
It sounds like you've answered your own question. If you don't retract the tool, it will leave a mark on the surface. This is mostly due to spring in the set-up, but even if there is no spring it will still leave a mark since the tool is generating a scalloped, threadlike surface as it feeds. If you drag it back across the surface, it will cut through those scallops and leave a track. Tom
Thanks, good idea with reverse count. You said that increased speed gives better surface finish. Why is this so? Adding the oil I understand is good, and lowering feedrate and plungedepth as well. But why to turning speed affect surface finish? Do you know?
Higher rpm will give a better finish as the "threads" of the finished surface will be closer together. With a light cut there is less heat to take away so you can get away with it. A rounded tool tip can also give a better finish too as you don't get the microscopic grooves.
No, Your feedrate is fixed ratio to the RPM. The speed helps in chip formation, if you go too slow it will be hit or miss if it actually cuts, usually leaving rings as the tool scrapes until it builds up enough material to form a chip which lasts for a very short time than breaks & repeats the cycle.
Thanks. If the rpm and feed rate are set set such that the cut is not generating excessive heat, coolant is not necessary. If you want to speed up the metal removal rate to the point where the chips start turning color when cutting steel, or start sticking to the tool when cutting aluminum, then coolant should be used. Tom
Thanks Tom. I'm contemplating building myself a piece of equipment that involves some knurling across a 2 m long 30 mm dia stainless steel shaft. Are machines capable of doing such a job readily available with machinists? P.S. I have zero knowledge about machining apart from the classes I took in Engineering school.
Sandarpan They are available. In fact in my latest project tutorial, I'm showing how to actually build one. Check out my clamp knurling tool videos, here or on my website. tomstechniques.com/ Tom
When your taking final diameter cut don’t you split the difference eg if you need to remove 2mm from 38mm OD then you move your cross slide in 1mm is that correct D0 - d1 divide by 2 correct?
Most cross feed dials are direct reading, meaning the graduations refer to the diameter of the part. The only indirect reading dials I have seen are on some old South Bend and Atlas lathes. The dial on the compound is always indirect reading.
Calipers are fast but not very accurate. They are best used for measuring flat surfaces, not round ones and especially not internal round ones. A micrometer is hard to beat for measuring external diameters and it doesn't have to be digital. For bores, you have lots of choices: Transfer tools like telescoping gauges and small hole gauges, and direct measuring tools like internal micrometers, gauge pins and dial bore gauges. Tom
Hi Tom, I have limited internet experience, but I have a southbend lathe and have been looking all over trying to find parts for it. Can you tell me where I might be able to look? I have already contacted southbend and they told me my machine is too old for them to help. I believe it was built in the 1940's. Thank you.
Sure. Go to plazamachinery.com. If you don't see what you want, give the guy a call. He has a lot more than what is listed on the site, and he knows South Bend's. Tom
Always use power feed when possible. It leaves a much more even finish on the part. There are many variables that affect feed rate, such as the type of metal being cut, the depth of cut and the desired surface finish. At some point, I intend to do a video on how to choose an appropriate feed rate, but for now you'll just need to apply some common sense, ie. slower for deep cuts or fine finishes and faster for shallow cuts or when fine finishes are not necessary. Tom
Thanks, Tom. As a newbie, this stuff can't be too basic for me. When I heard you say your (gorgeous!) Hardinge can "easily" take a 0.104" cut from mild steel I wilted a bit. I think I still need to work on my tool grinding, but on my ancient 10" Logan I feel like I'm really pushing things at 0.025" on mild steel. Is that reasonable, or should I be able to take a heavier cut? "Buy a heavier lathe" is an absolutely acceptable answer as long as you're willing to deliver it to my wife. ;-)
The Logan is a nice lathe. It's been years since I've used one, but I would suspect you should be able to do better than .025". Try using a smaller nose radius on the tool, a smaller side cutting edge angle on your turning tool and keep all of the overhangs to a minimum. That will help prevent chatter.
I also noticed that your lathe differs from mine and all others that I've found, in that the cross-slide and longitudinal adjustment dials both read absolute travel in thousandths, so the diameter changes by two times the dial reading. What model lathe do you have?
That's not true Paul. Both the cross slide and compound dials indicate changes in diameter, not in the radius of the part. The lathe is a Hardinge HLV-H Toolroom lathe. The only lathes I know of that read radius on the cross slide are some of the older South Bend and Atlas lathes, although it is fairly common for the compound to read on the radius. I made a set of direct reading dials for my Dad's Atlas. You can see then in the internal threading video. Tom
Hi Tom, I am currently learning to use lathes at my engineering school in the UK. I am finding your tutorials very useful but there is 1 thing I am really struggling with. I fall behind in class because I take too long cutting material down to size. I tried taking off more material per cut but the machine seems like its not doing well at all, there is alot of smoke and noise, I need to get quicker. Is there a technique to achieving this? Currently I take off 0.1mm per cut, the rest take off up to 0.5mms and say they had no problem. We run the spindles at the same speeds, use the same cutting tools and materials.
.1mm and even .5mm are very light cuts. What type of machines are you working with? For end milling, I generally take 1/8 to 1/4 the diameter of the end mill for roughing cuts and much more on a lathe, if necessary. The trick to heavy cuts is to get everything as rigid as possible (both the tool and the work), use the proper cutting speed and use coolant to keep everything cool and well lubricated. There are also techniques such as plunge cutting that speed things up for pockets. I talk about that in some of my videos. Tom
You hold the workpiece into the chuck from the threaded side does it damage the thread if it does what are alternative holding methods on a engine lathe .I was thinking of using a nut of same size as the thread and fit the nut bolt assembly into the chuck .Please reply for the possible solution
I use a six jaw chuck and it puts very little pressure on the part. If you are concerned about damaging a part, you should place a piece of paper or sheet metal between the jaws and the surface of the part. A female thread is a great way to hold a part with a male thread, especially if the female thread is machined in place. That way the male part with have essentially zero runout. Tom
Vinayak Modi, it can and will damage the threads, unless you use light pressure. If you are concerned about the damage, and the concentricity of the thread to the portion that you are machining, you should make a sacrificial fixture by boring and chasing/tapping a matching internal thread. a split nut can also be used if the concentricity is not and issue.
You can make a drill cut slightly oversize by making the length of one cutting edge longer than the other, but the size would be unpredictable. You'd be much better off finding the proper size drill. Tom
I was wondering if there is any distinct advantage to using a micrometer to measure the outside diameter like shown in the beginning of this video, versus just using my digital calipers.
Power feed will generate a better surface finish than hand feeding the tool. The tool is stopped by disengaging the feed. Notice that the part is sticking out of the chuck a bit to make room to do so.
thank you sir. I just got a job as a machinist trainee i'll be starting Monday. I am also a student at a local college, but i have never gotten my hands on the lathe or mill. I have been watching your videos and I learned a lot. Monday is the real thing. Thank you for your advice and help!
just wondering, do you ever actually use the compound for parallel turning. I've been using a cnc at home but since I've gone to college we've been shown to use the compound instead of moving the carriage.
I can't think of one reason to do that. The compound is normally used to turn tapered diameters, which makes it a poor choice for turning something cylindrical. You would need to indicate it every time you used it. Tom
Good video, but if you need a precise size then you should turn the part leaving a few tenths of a thou on it, then polish the few tenths off with some fine emery. Easily done.
I can't recommend using emery cloth on the lathe because it is way too easy to lose a nail or a finger if it isn't used correctly. If you have a lathe that won't hold tolerances that close, a better option would be to file it to size. I also have a video out showing the proper technique for using a file on the lathe. Thanks for watching. Tom
Tom, apparently your lathe x axis feed reads direct, whereas my lathe, you have to double the number (radius vs diameter). When you say feed in 104 thou, it is actually feeding in 52 thou. What is your lathe?
Herb, Most lathes read diameter on the cross slide and radius on the compound. I haven't used one in years, but I think some of the South Bend lathes were the exception. That just falls under the category of you need to know your machine because they are all different. My lathe is a Hardinge HLV-H toolroom lathe. Thanks for watching. Tom
Tom's Techniques Tom, To Herb's point, my Atlas/Craftsman 12" lathe reads Radius, i.e. the setting is "per side". In your demo, I would have fed 52 thou on the dial to reduce the diameter 104 thou. Thank you so much for your informative videos.
I can not find a video where someone turns a pice with different diameter, like the engine cylindar shaft( not that dramatisk ofcourse ) was it maybe an idea for you hopefully to show us how its done
Hi Thank you very much for answering. Since then I have learned that the name of it is Eccentric turning, But I dont have a chuck with 4 jaws :( I only have a 3 jaw chuck. I have tried and it is possible but I dont know how to find out if the Eccentric turning will work to my specificatons. I couple of times and I haven't been able to get it right. Thre Arent much on youtube is there? I mean teaching how to.... Thank you very much. Keep it up. Love your video's
Eccentric turning can also be done using a fixture. A piece of round stock with an offset bore in it can be used to hold a part in a three jaw chuck. I will add that to my list of video topics. Tom
Yes I have found some youtube video's but most of them are done on a 4 jaw. I dont have a 4 jaw, and with a 3 jaw it seems that the only way is exactly have mentioned here. using something with a hole in where one can insert the item in and hold it while turning. I just was hoping that I could find a better or quicker way, but I guess one can not want too much from a thing which can not deliver ( the 3 jaw I mean ).Thank you very very much for answering my question, even thou I wish I had looked some more and then I had asked you a better question. Keep up the good work. I just everyone of your video's. GOOD LUCK...
Been fully retired for nearly four years. We have since sold our house and moved into a new one. I am also well into the process of building a new shop. Once that is done I will hopefully have time to make some new videos.
That can be done to turn to sub .001" tolerances if your lathe is capable of holding them (most are not). Of course you would need to calculate every move with trig. If I have to turn something that close, I normally aim a thousandth high and take a few spring passes until the diameter is correct. Tom
Hey Tom, there's a reference sheet, there's no reference sheet - it'd be good if there is a reference sheet. Any chances? - Great video's keep up the good work
It likely can take off that and more with a properly ground tool. On mine I can easily bury a 3/8" tool on a roughing cut. That's not always the fastest way to remove metal though. Multiple shallower passes at a high feed rate can be more efficient. Tom
Absolutely. And even that won't save you all the time. I once had metal dug out of my eye that made its way past the side shields on my safety glasses. No fun at all.
I assume you are talking about setting the tool to a finished surface? The best way to do that is to run the tool toward the stationary part (not running) with some sort of shim between the tool and part. Paper works well, or a piece of shim stock. Once the tool touches the shim, you know where it is relative to the work, and can then move it in the thickness of the shim and zero your dial. That puts the tool at the surface of the work, without damaging it.
PROJECT TOM - First of your videos I've watched. Pretty good content but I've one thing for you to reconsider ! It appears cross slide markings come in two types ! Units for linear movement and units for diameter. It appears yours is the latter but on other machines, users have to dived by 2 ! - so to take 104 thou off, dial would move 52 marks. It's also a bit odd the smaller you go with diameters, the higher the dial reading ! It would seem to be more sense if the cross slide dials were marked from the centre of the lathe outward, not inward ! So when approaching zero, you'd pass 20 then 10 down to zero - rather than up to zero ! Maybe that's a machining project for you at some point - make new dials that work the right way ! Embarrassing admission ! - it could be 15 years since I used our lathe. And I can't remember whether the feed dial are metric or imperial and whether the cross-feed is 'linear' or 'diametral' !!! Now, 1 question before I get to the PROJECT TOM bit.... 6 jaw chucks - what's the crack ? Yours is the second I've seen on YT videos - what's the pros & cons (over 3 jaw) ? Now for the killer project !!!!!!! I've been bemused by the number of jaw-truing videos I've seen and this mad enthusiasm for accuracy. It took me a while for me to realise what the problem was - they're doing it very wrong ! (In fact, most people are doing it wrong !) If you need to work accurately, put the work scruffily in the chuck, face and centre drill. Swap the work round, face the other end and centre drill. May be reasonable to rough out in the chuck but as soon as possible, take the chuck off and turn between centres - after all the machine is commonly called a centre lathe but so few people are using it as such, it's unbelievable ! So let's see far more stuff from you being turned between centres ! As if it's NORMAL ! :)
The only lathes I've ever seen that have direct reading cross slide are really old South Bend's, so It's not reaaly worth mentioning and confusing the beginner. Besides, if someone actually had a lathe like that, it wouldn't take them long to figure it out. :) Six jaw chucks are much more precise than three jaws, and put half the force per jaw on the work, so are less apt to marr it. Once you use one, you'll never go back. Once a chuck is worn, it can't be re-trued. The problem is that the wear occurs on the scroll plate, not the jaws, and it happens at the place where the chuck is most often used. You can true the jaws at that point, but then they eill be off everywhere else. Best thing you can do with a worn chuck is throw it away. Chucks are used for more than just center drilling, so they do need to run true.
@@TomsTechniques Cross slides - fair enough - I'm not aware of how many are one way or the other. 6-jaw - I did think with narrower jaw tips they could in fact dig in better and grip work better AND grip smaller work. Another thing to consider is that obviously they're spreading their work load over twice the area of scroll thread - so that should be better too. I guess I'd not looked at the engineering behind the fact there's twice as many jaws - so yes, there's quite a bit of logic to it - and possibly working towards being more like a collet chuck although not at all like that IYSWIM. I like your opinion/style re worn chucks! I guess with wear, most of it is on the scroll/jaw interface rather than the scroll 'bearings'. I think the basic principle of scroll chucks is sound but I think someone needs to create a fresh design - to hold the scroll more precisely and encourage users to keep the 'thread' well lubricated. That's really a job for grease - which sadly is ideal for swarf chips to stick to !
Thanks Lewis. The scope mount was a fun project. I definitely want to start up the videos again, but I'm so busy with this retirement thing, it may be a while. I suppose I could post a video on the cello I'm building, or the 1949 Frazer I'm restoring, but that doesn't have much to do with machining. :)
Although you were machining down to a diameter, all your measurements were referenced to the centre of the piece and you were taking cuts off the radius. ie. If the piece diameter, which is what you were checking with the micrometer, is 10 thou over and you take a 10 thou pass, the piece diameter will now be 10 thou *under!* Ps. I didn't see any soft packing where the threaded portion was being held in the chuck. Not best practice if the thread is important.
I was working on a lathe with a direct reading dial on the cross slide, so there is no need to correct for radii vs diameter. Most lathes are like that, save a few old South Bend's. The stock used in the demo was pulled from the scrap bin but yes, protecting a finish machined surface is always an option.
"Undersize" is a relative term. Real parts have tolerances associated with them and as long as the dimensions fall within those tolerances, they are good.
Tom Thankyou for your speedy reply. I appreciate you were only 1/2 a thou under but you miked the diameter and noted you only had 12 thou to go. When you put on a cut of 12 thou you took off 12 1/2 thou. Suppose this was a piston which had to be 1,125 and you wanted to lap off the last 1/2 thou or so. How do you make sure you dont cut a 1/2 thou too small without creeping up on your chosen dimension by taking smaller and smaller cuts? Is there a way? I only ask because quite often I end up taking smaller and smaller cuts as I get towards the size I need and it takes a lot of time. I think it's also not good for the tool to take tiny cuts. Thanks for any help you can give.
If I really wanted to hold the nominal dimension I would have taken the last .012" off in two cuts. That way each of those cuts would be identical, and the first one would provide the opportunity for a careful measurement to dial in the final cut.
No John. You have to realize that the numbers on the dial are relative, depending on which side of zero you are working. I set the dial to zero and turned it .104" counter-clockwise, ending up on .096". Turning the crank clockwise back to zero advanced the tool .052", taking .104" off the diameter of the part. Tom
Great video Tom! Here's a trick I learned from an old German toolmaker: rather than sneak up on a size, when I want to turn to a +/- 0.0002 tolerance, I snug up lightly on the the ways for cross slide and carriage, and lock down the compound. If I'm turning common-as-dirt 1018 cold roll, I normally use carbide inserts, but to keep with your example, using a HSS tool I would crank the rpms up so the SFM is 135 ft per min., or ~435 to 450 rpm for 1-1/8 stock and a target of 1.0000". I'd use a sharp tool with a nose radius of 0.016 to 0.018, and feed at 0.002" to 0.004" per rev depending on the desired surface finish.. As you show, its very important to get the tool on center. Then take a "skim cut", as you did, but turn across the full width of the part. Let the part cool if needed ( or run coolant), and mic it. Let's say it mic'd 1.1083". Set a dial indicator to pickup the cross slide movement & zero the indicator. Next subtract target dimension from the skim cut diameter ( 1.1083 - 1.0000 = 0.1083) Divide this amount by any whole number that will give a result that is equal to or slightly larger than the tool's nose radius. For example, 0.1083 / 6 = ~0.018" and a close enough match for our tool nose R.. This gives us the depth of cut ( radius to dial in for the first of 6/2 or 3 passes. This cut should mic at 1.1083 - 0.036" = 1.0723. Let the work cool if needed and mic it. Lets say it mics 1.0731. Subtract our target (1.0731-1.0000 = 0.0731. Divide by the number of remaining passes (2) = ~ 0.0366", Divide by this amount by 2 and dial in this DOC, This pass should mic 1.0731 - 0.0366 = 1.0365. Let the part cool, mic it. Let's say is mikes 1.0368. Repeat the process, in this case 1.0368 - 1.0000 = 0.0368. Divide by 2 and dial in the DOC for this last pass. Let the part cool in needed, and mic it. You'll be within 1 to 2 tenths, if not dead on size. The math may seem complex here, but it can readily be done in ones head once you understand the process. This works because it reduces tool nose pressure ( by taking a cut that is equal to or greater than the nose radius) and by compensating and adjusting for any residual pressure or part flex over nearly consistent tool pass pararmeters. Give it a try - it really works - and especially when boring an ID. Google "Sanvik 3 Pass Method" for better how-to info on boring a close tolerance hole using this method. (By the way, the method I described here works on my newest CNC lathe, as well as my 43 year old 15" Clausing, my old pre-WW11 Southbend, and my little Chinese wonder from Enco :-) Accuracy is 99% machinist technique, and 1% machine :-)
Thanks again for the great videos!
Thanks Ed, I haven't heard of that technique before, but it does make sense. Not sure I understand the need for all the math gyrations though. The object seems to be to limit the depth of cut to the radius of the tool to reduce part flex and heat , so why not just take a cut and divide the remainder by 2X the tool radius to get the required number and depth of cuts?
Tom
Toms Techniques each pass is adjusted a few tenths so the last pass is dead on. Sandvik's can explain better. :-)
this method works very well when boring too. we use it for turning & boring on cnc & manual lathes. always excellent results.
Tom, I just want to personally tell you thank you. All that you did, to help us beginners out, I can speak for myself here; gratitude! I hope you can hear it personally. Your time/kindness will never be forgotten. Thank you Brother. --Joe
Thanks, Joe!
Wow, these videos are amazing. A rare combination of expertise on the subject, great teaching, and quality camera work. I usually find videos to help me accomplish a specific task, but I am watching these for fun like a football game. Other good resources I have used to learn machining and fabrication skills are Machine Shop Essentials, Questions and Answers by Frank Marlow, and my favorite book on the subject, Metalworking, Sink or Swim by Tom Lipton. He has some very funny stories in addition to sharing his tips and tricks he learned over a career as a metal worker. I never got the chance to take metal working classes in high school, but it feels like I have the best shop teacher in the world now. Thanks, Tom!
I'm a qualified fitter and turner and I love doing anything on the lathe and milling machine. I love to see videos like this out there to teach the younger generation. To the 23 that disliked the video, I think they must be some sort of dress makers. LOL. Thank you sir for the teaching.
Thanks Brent
It is the basics that are the foundation to good machining techniques. I always enjoy watching your videos!
Thanks, and I wholeheartedly agree. I plan on doing a lot more on the basics once I get back into making videos. Right now I'm working on learning how to function with this new retirement thing. :)
Tom
Thanks Tom For us beginners your detailed discussion and excellent filming is really very helpful I look forward to seeing your other vids in the future.
Great videos. Thank you for sharing your knowledge. Took your advice from the 'parting video' and ordered a quick change tool post. 1955 9 inch Southbend...worn out, but we get by.
Tom, Glad I found your channel. You have a great way of describing and showing operations in a simple easy to understand way. Please keep 'em coming!
Thanks LB, I'm glad you like them.
Tom
That was great advice Tom, I have been struggling with getting accuracy from my dials. I discovered one thing of importance, I had movement in the dial after I took the back lash out. I pulled the rod and shoe and couldn't see anything wrong. I have a 1960 13" South Bend Lathe. The screw head is slotted so I took a screw driver and tightened it. This did what it should be doing, no extra movement other than back lash. Thanks so much for the lesson and advice.
Such fantastic videos! I've been watching for hours and see no end in sight! I have learned more today watching your series of videos than I have in all of my other "Youtubing" and reading! your teaching style speaks well to how I learn! I am getting very excited to apply all of my new found knowledge on the lathe! Very excited!!! Thank you!
+Nikolas Christian
It's always good to hear from a satisfied "customer".
Thanks for watching!
Tom
anyone who dislikes this , should not be watching teaching videos. Great vid Tom.
Thanks Tom. I always learn something when I watch one of your videos.
Thanks for watching, Mike.
Thanks for your videos Tom - as a 'noobie' I am enjoying watching all of them. My Hardinge HLV arrives in early January and most of the people I have spoken to regarding tooling have pretty much insisted that carbide inserts are the way to go - however I am buying a bunch of HSS blanks and a decent grinder and will also try and teach myself how to grind my own - your videos have been helpful
All the best
Pete
This is how I do it on parts that must not be scrapped (large price tag): after roughing I run spring pass to remove any material that was left by roughing tool deflection, then I measure the part. I may take light semi-finishing pass to leave myself desired amount of material for finishing pass.I stop the machine, and cool the part down with coolant running for a few minutes. I then measure the part, move tool to finishing diameter ,and run the pass for the length of 0.25" then stop the machine ( I do not let tool run to the end yet !) I measure the part to make sure size is ok, then continue the pass. Sometimes there will be a witness mark where the tool was stopped so I polish that off at the end. If I measured that the part was undersize, I adjust, and only that first 0.25" will be undersize ( hopefully the customer will forgive:). Imagine that you let the tool run to the end because you trusted your machine ,just to find out that you are 0.001" under for the entire length!
Tom, thanks for the videos! I watched them as they came out, but since I recently got a 1955 South Bend 9" lathe I'm watching them again. Actually being able to try what you are showing is different from just watching...and tells me what I need to see again.
I hope all is well with you and yours.
-- Mike
Thanks Mike.
Now that the weather is turning cold, I'm getting geared up for another round of videos. A Shure wireless mic that I won on eBay showed up in the mail today and hopefully it will improve the sound quality in my videos. I'm actually in town this weekend for the first time in a month, so maybe I'll get a chance to try it out.
South Bend makes a nice for light machining. It should serve you well.
Tom
It's always fun to get new tools, whether mics or lathes. The South Bend is a small lathe, but I'm only making small things for now, so that's fine. It's in good shape (only two prior owners, both hobbyists who took good care of it), and it came with a bunch of accessories, including a milling attachment and a lever-operated turret tailstock (in addition to the normal kind). No 3-Jaw, but it does have a 4-jaw and a collet chuck, so no limitation there except on speed of chucking. I turned and milled the T-nut for a QCTP ok, and I'm making a few other small tools and add-ons...so far so good thanks to your videos and some others I've watched. Without that I'd still be wondering how to make it go! I'll be downloading your toolbit grinding PDFs next...just received some blanks I ordered. Thank you for the help!
-- Mike B.
Thanks Tom, every little bit helps.Allways good to see how a Pro does it.
Thanks Cliff.
Hi Tom,I love your common man approach. Thanks.
+K Gee
Thanks for watching
Thank you Mr. Tom. Your videos are excellent, cheers.
Thank you for watching
Hi Tom,
I have been watching a few of your videos and have to say I like them all.
Thanks!
Thanks for watching.
Hi Tom....
Nice chips! Reverse counting always confuses me, but I guess it is just a mindset and I need to push myself to practice and change my methods. I watch my in shop mentor, a retired tool maker, use this method all the time!
Happy Holidays! Really enjoy your lessons!
Chuck
Thanks Chuck. I think you might find it easier once you make the transition.
Loving your videos, learning lots before I start using my new mini lathe. So glad we work in metric in the UK now, imperial sounds so complicated 😁
The Imperial system isn't complicated at all if that's what you are used to. First thing most shops do here if they receive a Metric drawing is convert the dimensions to inches. By the way, I understand you guys still use a number of Imperial measurements as well, so maybe the Metric system isn't all it's cracked up to be. ;)
Imperial isn't complicated, but the tendency for micrometers to measure in thou (or smaller) is a bugger when many sizes are in x/8, x/16, x/32, etc. You can convert with tables or calculate them on the fly, but it's an unnecessary step that is prone to introducing errors.
Just found your videos , just what I needed thank you
You are very welcome
great demonstration and helpful tips. thank you
Hi Tom, another good video, not necessarily the way I do it, but when asked I can confidently recommend your channel to beginners as a good place to start as your videos are clear, concise and to the point and without dogma, unlike certain beginner orientated channels.
Re dia/ rad cross slide dials, the convention this side of the pond is that Imp lathes are Rad and Metric ones are Dia, not a hard and fast rule just convention.
ATB
chris
Thanks Chris.
I don't think that applies over here. Most of the industrial lathes I've used read diameter on the cross slide and radius on the compound. One exception are the older South Bend lathes. I seem to remember some of them read the radius on the cross slide.
Tom
Learning a lot, great videos Tom - Thanks
Machinist Apprentice Bill
Thanks Bill.
Yes it takes a lot of selflessness attitude to educate the masses to put up video's and expose yourself to trolls, good on you for making the time to keep machining alive, ignore the snowflakes that like to leave a thumbs down.
Thanks Glen. Unfortunately, leaving a thumbs down on a video is the only feeling of power some can attain.
Tom I have been watching your videos for quite some time. After several of your lathe series I have become interested in what kind of lathe you have. It has some features that really interest me.
Thanks for all the effort you put into your videos!
Keith Mifflin
Keith,
My lathe is a Hardinge HLV-H Toolroom lathe. I bought it new in the mid eighties and in my opinion, it's the best lathe available for the one off type of work I do. Unfortunately, they are no longer in production, but there are copies and quite a few used ones around.
Tom
Thanks, Tom. I really love your videos and the way you explain things. Wish I had your experience! :) Looking forward for your next videos.
Glad you are enjoying the videos. I have the whole week off over Christmas, so I should be able to come up with a few new ones.
Tom
Thanks Tom! Oh that hurts when you are in a class where none of the students know what they are doing....one minute its there and the next its gone! But now I get it....find out the diameter you need; find out how much you need to take off to achieve that diameter; zero the diameter you have; and take off the amount you need to achieve your final diameter. Hopefully I will never forget again! Oi! CAT
Thanks Tom, great video
G'day Tom just subscribed thank you for your easy to follow videos, really helps a lot when you are starting out. One video which I am interested in was grinding your own cutting tools as I would prefer to do this myself. Thank you kind regards John Tasmania Australia
+John Kinnane
Thanks John. Good to hear you are enjoying them.
Tom (from Michigan, USA)
Nice man, just what I need. Cant wait to go through the rest of your videos.
Subscribed.
Thanks. Glad it was useful for you.
I like that Harding Lathe! And you too!
Good video Tom very helpful. Perhaps a video in the future on basic insert tools and how to set them up on the lathe?
Sorry Bill but I'm not a fan of carbide inserts on light machinery. HSS will produce a better finish, is more forgiving, more flexible, more economical and all in all a much better option for the home machinist.
Tom
Tom's Techniques There are HSS inserts out there as well, Dear Tom. Maybe you could make a video on those? If you have them on hand, of course. I know Arthur Warner Co. makes HSS inserts. Made in USA! ;)
Great video as always. Thanks.
Thank you for all your help!!!!!
Thanks for watching!
Nice video. I found it a bit ironic when you mentioned to be careful to not move the cross slide crank at 7:47 on the video considering that you did accidentally move the crank between 7:34 and 7:40. Although to be fair, I don't know if the movement was within the slack that causes backlash or not. But in any case, the crank is visibly moved a few degrees.
Thanks for pointing that out. You might also notice that when I took the trial cut after setting the dial, I realized the error at 10:20 and was able to correct it before taking the finish cut. All machinists make mistakes, the good ones recover from them before they become permanent.
Tom
You Rock mate. Thanks for the videos.
+Marcelle Smit
Thanks for watching!
Thanks for another video, Tom. On my Hardinge HC, I'm unable to lock down the hand wheel to set my dial. For now, I've been holding the wheel, and adjusting the dial. I see you have a little set screw on your machine. The only manual I have is online, and for an HC, which doesn't cover locking the hand hweel down. I'd appreciate any quick pointers you could give. Thanks again.
Thanks Aaron.
I'm not familiar with the HC, but it doesn't look like the cross slide dial is the same as mine. There might be a spring inside to provide friction and let you set it by holding the crank.
Tom
I like your way of thanking and thank you the video
Glad you enjoyed the video.
fantastic instructional videos
+Ed Ginsberg
Thank you. I hope to get started on some new ones tomorrow.
Tom
Very nice..... Just so e food for thought. Could you show us how to drill really really super small holes that are accurate and won't break off your drill bit..... Also... Cover how to best use reamer's.
The trick with small drills is an insanely high rpm. A 1/16" drill for instance, should be spun at 6500 rpm to prevent. Any small drill like that should also be spotted with a center drill to help it start on location.
A video on reamers is a good idea, I'll add it to the list.
Thanks for the comments and the suggestion.
Tom
Cool thanks. I have to turn down to a shoulder so I will try rotating the bit some. You mentioned making another tool with no side angle so I assume it would look like a facing bit? Except perhaps you keep the angle at 90 vs. 70 is what I would think but don't really know. Anyways cool vid. The reverse count threw me for a loop but that's pretty cool after I understood that.
I also see you mention casting here and there.....I actually built the Gingery charcoal furnace but I haven't got past melting down engine blocks and making ingots yet. I was going to make the lathe but decided id rather go straight to making stuff I need rather than go that route. Time is a big factor. Being a sheetmetal worker for 15years this has opened up a whole new level of fabrication for me and I am frustrated on a daily basis that I never learned this stuff a long time ago.
Hey Tom, love the videos. Im a welder fabricator by trade, but love to machine parts up at work after hours, Ive been having a problem when I'm turning long parts to diameter. I turned a part that was 18-1/2" long and 1-1/4" down to 1-1/8" and I was 0.015" off from one end to the other. It hasn't been a big problem so far, but I would love to know how to get ride of that slop in the part. Thanks again
You need to use a steady rest or follower rest for parts that long to keep the center, unsupported section of the part from pushing away from the tool.
Tom
If you had the work supported at the tailstock, with a live center and the part was different diameters at each end, you need to adjust the tailstock so it is indeed centered on the chuck. The center of the part will also be different if you don't do as Tom suggested. The tool will push the work away, essentially taking less of a cut than you think it just took.
we can measure with a vernier caliper also right?
Excellent informative
100% on eye protection 👍
Hey whats up Tom good video. I skipped a small portion of the video so I am not 100% sure if you did or not say it but I was wondering if you mentioned that when you add on a diameter with the dial that you are actually doubling what you are cutting? I have never operated a retail lathe I have a homemade lathe so I am not sure if the dial accounts for that.
Basically when one cuts on a diameter with a lathe they have to advance half the amount of the total difference because if you set it to 5 thousandths you are really taking off 10 thousandths of the total diameter since 5 thousandths is being removed all around and both measuring points. I apologize if I missed this or I am misunderstanding something here. Take care...
+Micscience
On most lathes, the cross feed dial reads diameter directly. In other words, if you move the dial .010" then the diameter will be reduced by .010". The dial on the compound does not compensate. It moves the tool whatever the dial says.
Thanks for watching.
Tom
How are you securing the stock to the jaws?
Understood; and a well explained video. As always, thanks’ for taking the time to make this video! And I support this site. ~M~
PS: this may be my “tagline” until I have a question?
Would you not instruct that when setting up your work that you first check the chuck clearance by moving the spindle by hand and then move the X and Y axis to check if the chuck will strike the bit holder or the bit when the holder is close to the chuck? Thumbs up.
Hi Tom, I really enjoy your videos and have found them really instructional. I am a complete novice so please excuse my questions if they seem simplistic. When you did the facing video you rough cut outside to centre and then finished centre to outside. In this turning to dia video you went longtitudinally from the tailstock end on each cut, including the finishing cut. I was just wondering if the reason was because it was because of the way the tool was ground. Many thanks, Gordon
+Gordon Agent
Hi Gordon,
You will always get a better finish facing while feeding from the center out because of the shallow angle of the side cutting edge. You may or may not get a better finish that way when turning, depending on the material. In this case, the material was leaded steel so I got a nice finish on the first cut, and didn't need to take a finish cut left to right. Machining is all about making judgements based on results and the only way to learn how to do that is through experience.
Tom
Good video as usual. One question about returning the cutting tool to the start position. Do you always retract the tool from the work when you return the tool to take another cut? I have noticed when I return the tool to the start position without retracting, it still cuts. Can you tell me why that is?
It sounds like you've answered your own question. If you don't retract the tool, it will leave a mark on the surface. This is mostly due to spring in the set-up, but even if there is no spring it will still leave a mark since the tool is generating a scalloped, threadlike surface as it feeds. If you drag it back across the surface, it will cut through those scallops and leave a track.
Tom
Thanks, good idea with reverse count. You said that increased speed gives better surface finish. Why is this so? Adding the oil I understand is good, and lowering feedrate and plungedepth as well. But why to turning speed affect surface finish? Do you know?
Higher rpm will give a better finish as the "threads" of the finished surface will be closer together. With a light cut there is less heat to take away so you can get away with it. A rounded tool tip can also give a better finish too as you don't get the microscopic grooves.
No, Your feedrate is fixed ratio to the RPM. The speed helps in chip formation, if you go too slow it will be hit or miss if it actually cuts, usually leaving rings as the tool scrapes until it builds up enough material to form a chip which lasts for a very short time than breaks & repeats the cycle.
Great vid. Why didn't you use cutting fluid on the roughing cuts?
Thanks.
If the rpm and feed rate are set set such that the cut is not generating excessive heat, coolant is not necessary. If you want to speed up the metal removal rate to the point where the chips start turning color when cutting steel, or start sticking to the tool when cutting aluminum, then coolant should be used.
Tom
Thanks Tom. I'm contemplating building myself a piece of equipment that involves some knurling across a 2 m long 30 mm dia stainless steel shaft. Are machines capable of doing such a job readily available with machinists?
P.S. I have zero knowledge about machining apart from the classes I took in Engineering school.
Sandarpan
They are available. In fact in my latest project tutorial, I'm showing how to actually build one. Check out my clamp knurling tool videos, here or on my website.
tomstechniques.com/
Tom
That's a sweet chuck.
nunya bizniss
Yes it is. :)
When your taking final diameter cut don’t you split the difference eg if you need to remove 2mm from 38mm OD then you move your cross slide in 1mm is that correct D0 - d1 divide by 2 correct?
Most cross feed dials are direct reading, meaning the graduations refer to the diameter of the part. The only indirect reading dials I have seen are on some old South Bend and Atlas lathes. The dial on the compound is always indirect reading.
What is a better measuring tool for basic O.D. and I.D. measurements, digital calipers or a digital micrometer? Thanks
Calipers are fast but not very accurate. They are best used for measuring flat surfaces, not round ones and especially not internal round ones.
A micrometer is hard to beat for measuring external diameters and it doesn't have to be digital. For bores, you have lots of choices: Transfer tools like telescoping gauges and small hole gauges, and direct measuring tools like internal micrometers, gauge pins and dial bore gauges.
Tom
Hi Tom, I have limited internet experience, but I have a southbend lathe and have been looking all over trying to find parts for it. Can you tell me where I might be able to look? I have already contacted southbend and they told me my machine is too old for them to help. I believe it was built in the 1940's. Thank you.
Sure. Go to plazamachinery.com. If you don't see what you want, give the guy a call. He has a lot more than what is listed on the site, and he knows South Bend's.
Tom
Great video. A+++.
HI Tom, really like your videos. Were you moving the tool longitudinal by hand crank or automatically? What's a good speed to do this?
Always use power feed when possible. It leaves a much more even finish on the part. There are many variables that affect feed rate, such as the type of metal being cut, the depth of cut and the desired surface finish. At some point, I intend to do a video on how to choose an appropriate feed rate, but for now you'll just need to apply some common sense, ie. slower for deep cuts or fine finishes and faster for shallow cuts or when fine finishes are not necessary.
Tom
Thanks, Tom. As a newbie, this stuff can't be too basic for me. When I heard you say your (gorgeous!) Hardinge can "easily" take a 0.104" cut from mild steel I wilted a bit. I think I still need to work on my tool grinding, but on my ancient 10" Logan I feel like I'm really pushing things at 0.025" on mild steel. Is that reasonable, or should I be able to take a heavier cut? "Buy a heavier lathe" is an absolutely acceptable answer as long as you're willing to deliver it to my wife. ;-)
The Logan is a nice lathe. It's been years since I've used one, but I would suspect you should be able to do better than .025". Try using a smaller nose radius on the tool, a smaller side cutting edge angle on your turning tool and keep all of the overhangs to a minimum. That will help prevent chatter.
I use an Okuma 8 inch lathe and able to take a 0.025 DOC (0.050 off the diameter) in mild steel with no problem. Twice that on aluminum and 360 brass.
I also noticed that your lathe differs from mine and all others that I've found, in that the cross-slide and longitudinal adjustment dials both read absolute travel in thousandths, so the diameter changes by two times the dial reading. What model lathe do you have?
That's not true Paul. Both the cross slide and compound dials indicate changes in diameter, not in the radius of the part. The lathe is a Hardinge HLV-H Toolroom lathe. The only lathes I know of that read radius on the cross slide are some of the older South Bend and Atlas lathes, although it is fairly common for the compound to read on the radius. I made a set of direct reading dials for my Dad's Atlas. You can see then in the internal threading video.
Tom
Hi Tom, I am currently learning to use lathes at my engineering school in the UK. I am finding your tutorials very useful but there is 1 thing I am really struggling with. I fall behind in class because I take too long cutting material down to size. I tried taking off more material per cut but the machine seems like its not doing well at all, there is alot of smoke and noise, I need to get quicker. Is there a technique to achieving this? Currently I take off 0.1mm per cut, the rest take off up to 0.5mms and say they had no problem. We run the spindles at the same speeds, use the same cutting tools and materials.
.1mm and even .5mm are very light cuts. What type of machines are you working with? For end milling, I generally take 1/8 to 1/4 the diameter of the end mill for roughing cuts and much more on a lathe, if necessary. The trick to heavy cuts is to get everything as rigid as possible (both the tool and the work), use the proper cutting speed and use coolant to keep everything cool and well lubricated.
There are also techniques such as plunge cutting that speed things up for pockets. I talk about that in some of my videos.
Tom
.1mm is a small cut i personally take .050/inch per pass until I get it down to .050 within the size i am trying to turn to
You hold the workpiece into the chuck from the threaded side does it damage the thread if it does what are alternative holding methods on a engine lathe .I was thinking of using a nut of same size as the thread and fit the nut bolt assembly into the chuck .Please reply for the possible solution
I use a six jaw chuck and it puts very little pressure on the part. If you are concerned about damaging a part, you should place a piece of paper or sheet metal between the jaws and the surface of the part. A female thread is a great way to hold a part with a male thread, especially if the female thread is machined in place. That way the male part with have essentially zero runout.
Tom
Vinayak Modi, it can and will damage the threads, unless you use light pressure. If you are concerned about the damage, and the concentricity of the thread to the portion that you are machining, you should make a sacrificial fixture by boring and chasing/tapping a matching internal thread. a split nut can also be used if the concentricity is not and issue.
easy to listen to and learn from
Thanks Phil
great video
Thanks
I have a standard diameter drill but I want to give it a non-standard diameter because I can not find that diameter in stores. How can you adjust it?
You can make a drill cut slightly oversize by making the length of one cutting edge longer than the other, but the size would be unpredictable. You'd be much better off finding the proper size drill.
Tom
I'm tamilnadu like it u work
I was wondering if there is any distinct advantage to using a micrometer to measure the outside diameter like shown in the beginning of this video, versus just using my digital calipers.
The micrometer is more accurate and repeatable.
Calipers will get you within .003", micrometers will get you within .0001.
Micrometer is more accurate and dependable.
thank you sir. I have 2 qs one is did you move the tool by hand or using the automatic feature? 2 is how do i stop the tool before hitting the chuck?
Power feed will generate a better surface finish than hand feeding the tool.
The tool is stopped by disengaging the feed. Notice that the part is sticking out of the chuck a bit to make room to do so.
thank you sir. I just got a job as a machinist trainee i'll be starting Monday. I am also a student at a local college, but i have never gotten my hands on the lathe or mill. I have been watching your videos and I learned a lot. Monday is the real thing. Thank you for your advice and help!
just wondering, do you ever actually use the compound for parallel turning. I've been using a cnc at home but since I've gone to college we've been shown to use the compound instead of moving the carriage.
I can't think of one reason to do that. The compound is normally used to turn tapered diameters, which makes it a poor choice for turning something cylindrical. You would need to indicate it every time you used it.
Tom
Thank you :thank you so much
Good video, but if you need a precise size then you should turn the part leaving a few tenths of a thou on it, then polish the few tenths off with some fine emery.
Easily done.
I can't recommend using emery cloth on the lathe because it is way too easy to lose a nail or a finger if it isn't used correctly. If you have a lathe that won't hold tolerances that close, a better option would be to file it to size. I also have a video out showing the proper technique for using a file on the lathe.
Thanks for watching.
Tom
Tom,
apparently your lathe x axis feed reads direct, whereas my lathe, you have to double the number (radius vs diameter). When you say feed in 104 thou, it is actually feeding in 52 thou. What is your lathe?
Herb,
Most lathes read diameter on the cross slide and radius on the compound. I haven't used one in years, but I think some of the South Bend lathes were the exception. That just falls under the category of you need to know your machine because they are all different. My lathe is a Hardinge HLV-H toolroom lathe.
Thanks for watching.
Tom
Tom's Techniques
Tom,
To Herb's point, my Atlas/Craftsman 12" lathe reads Radius, i.e. the setting is "per side". In your demo, I would have fed 52 thou on the dial to reduce the diameter 104 thou.
Thank you so much for your informative videos.
My dad's Atlas reads diameter on the cross slide, and I've used older South Bends that read the radius. You just have to know your machine.
Tom
I can not find a video where someone turns a pice with different diameter, like the engine cylindar shaft( not that dramatisk ofcourse ) was it maybe an idea for you hopefully to show us how its done
I'm not sure I understand your question. Do you mean different diameters on the same shaft, or do you mean offset diameters like on a crankshaft?
Tom
Hi Thank you very much for answering. Since then I have learned that the name of it is Eccentric turning, But I dont have a chuck with 4 jaws :( I only have a 3 jaw chuck. I have tried and it is possible but I dont know how to find out if the Eccentric turning will work to my specificatons. I couple of times and I haven't been able to get it right. Thre Arent much on youtube is there? I mean teaching how to.... Thank you very much. Keep it up. Love your video's
Eccentric turning can also be done using a fixture. A piece of round stock with an offset bore in it can be used to hold a part in a three jaw chuck. I will add that to my list of video topics.
Tom
Yes I have found some youtube video's but most of them are done on a 4 jaw. I dont have a 4 jaw, and with a 3 jaw it seems that the only way is exactly have mentioned here. using something with a hole in where one can insert the item in and hold it while turning. I just was hoping that I could find a better or quicker way, but I guess one can not want too much from a thing which can not deliver ( the 3 jaw I mean ).Thank you very very much for answering my question, even thou I wish I had looked some more and then I had asked you a better question. Keep up the good work. I just everyone of your video's. GOOD LUCK...
love the videos subscribed.
Zac Youngson
Thanks Zac!
what lathe bit do i need to do this type of turning?
That would be a right hand turning tool. Go to my website, tomstechniques.com and look in the reference section for info on how to grind it.
Tom
You must be almost retired by now tom, congratulations! And great for us you will have lots of time to make new videos. :)
Been fully retired for nearly four years. We have since sold our house and moved into a new one. I am also well into the process of building a new shop. Once that is done I will hopefully have time to make some new videos.
How about a video using the compound on an angle to sneak up on an exact diameter.
That can be done to turn to sub .001" tolerances if your lathe is capable of holding them (most are not). Of course you would need to calculate every move with trig. If I have to turn something that close, I normally aim a thousandth high and take a few spring passes until the diameter is correct.
Tom
Tom's Techniques Mrpete222 has a video on using the compound slide for small movements,very informative.....
Hey Tom, there's a reference sheet, there's no reference sheet - it'd be good if there is a reference sheet. Any chances? - Great video's keep up the good work
fayvinplace
Have you been to the website? You'll find an rpm reference sheet there for popular alloys under "Reference".
tomstechniques.com/
No I hadn't Tom - I have now though - thanks for the link and the sheet. Cheers
I wish my lathe could easily take off .100 in one pass!
It likely can take off that and more with a properly ground tool. On mine I can easily bury a 3/8" tool on a roughing cut. That's not always the fastest way to remove metal though. Multiple shallower passes at a high feed rate can be more efficient.
Tom
For me, a finishing cut nearly always produces a slightly undersized part - 1 half to one thousandths etc. Why is this?
The end mill can pull in a bit when conventional milling, but a half to one thousandth is hardly worth the concern on a mill.
always wear eye protection! I've got spots on mine from chips that if I didn't have them on would've been in my eyes!!!
Absolutely. And even that won't save you all the time. I once had metal dug out of my eye that made its way past the side shields on my safety glasses. No fun at all.
Awesome video Tom. Do you find when you "touch off" for your zero that your actually going in a few thou?
I assume you are talking about setting the tool to a finished surface? The best way to do that is to run the tool toward the stationary part (not running) with some sort of shim between the tool and part. Paper works well, or a piece of shim stock. Once the tool touches the shim, you know where it is relative to the work, and can then move it in the thickness of the shim and zero your dial. That puts the tool at the surface of the work, without damaging it.
Great skills, but we need to hear all that in metric units now!
Just divide everything by .03937. :)
Terima kasih.
You are welcome
PROJECT TOM -
First of your videos I've watched.
Pretty good content but I've one thing for you to reconsider ! It appears cross slide markings come in two types ! Units for linear movement and units for diameter. It appears yours is the latter but on other machines, users have to dived by 2 ! - so to take 104 thou off, dial would move 52 marks. It's also a bit odd the smaller you go with diameters, the higher the dial reading ! It would seem to be more sense if the cross slide dials were marked from the centre of the lathe outward, not inward ! So when approaching zero, you'd pass 20 then 10 down to zero - rather than up to zero ! Maybe that's a machining project for you at some point - make new dials that work the right way !
Embarrassing admission ! - it could be 15 years since I used our lathe. And I can't remember whether the feed dial are metric or imperial and whether the cross-feed is 'linear' or 'diametral' !!!
Now, 1 question before I get to the PROJECT TOM bit....
6 jaw chucks - what's the crack ? Yours is the second I've seen on YT videos - what's the pros & cons (over 3 jaw) ?
Now for the killer project !!!!!!!
I've been bemused by the number of jaw-truing videos I've seen and this mad enthusiasm for accuracy. It took me a while for me to realise what the problem was - they're doing it very wrong ! (In fact, most people are doing it wrong !) If you need to work accurately, put the work scruffily in the chuck, face and centre drill. Swap the work round, face the other end and centre drill. May be reasonable to rough out in the chuck but as soon as possible, take the chuck off and turn between centres - after all the machine is commonly called a centre lathe but so few people are using it as such, it's unbelievable ! So let's see far more stuff from you being turned between centres ! As if it's NORMAL ! :)
The only lathes I've ever seen that have direct reading cross slide are really old South Bend's, so It's not reaaly worth mentioning and confusing the beginner. Besides, if someone actually had a lathe like that, it wouldn't take them long to figure it out. :)
Six jaw chucks are much more precise than three jaws, and put half the force per jaw on the work, so are less apt to marr it. Once you use one, you'll never go back.
Once a chuck is worn, it can't be re-trued. The problem is that the wear occurs on the scroll plate, not the jaws, and it happens at the place where the chuck is most often used. You can true the jaws at that point, but then they eill be off everywhere else. Best thing you can do with a worn chuck is throw it away. Chucks are used for more than just center drilling, so they do need to run true.
@@TomsTechniques Cross slides - fair enough - I'm not aware of how many are one way or the other.
6-jaw - I did think with narrower jaw tips they could in fact dig in better and grip work better AND grip smaller work. Another thing to consider is that obviously they're spreading their work load over twice the area of scroll thread - so that should be better too. I guess I'd not looked at the engineering behind the fact there's twice as many jaws - so yes, there's quite a bit of logic to it - and possibly working towards being more like a collet chuck although not at all like that IYSWIM.
I like your opinion/style re worn chucks! I guess with wear, most of it is on the scroll/jaw interface rather than the scroll 'bearings'. I think the basic principle of scroll chucks is sound but I think someone needs to create a fresh design - to hold the scroll more precisely and encourage users to keep the 'thread' well lubricated. That's really a job for grease - which sadly is ideal for swarf chips to stick to !
I never knew Norm MacDonald was a machinist
I didnt understant that,,, surely you need to remove half of 104thou,,, 52??? if you push the tool into the bar 104 it will be 208 smaller in dia??
Most cross slide dials are direct reading, meaning that the read the diameter, not the radius.
What happen to Tom? I instantly subscribed.
Still here enjoying retirement and building a new shop. More to come when things settle down.
@@TomsTechniques looking forward to your return, your scope mount video was the answer to so many problems I had. I like your style.
Thanks Lewis. The scope mount was a fun project. I definitely want to start up the videos again, but I'm so busy with this retirement thing, it may be a while. I suppose I could post a video on the cello I'm building, or the 1949 Frazer I'm restoring, but that doesn't have much to do with machining. :)
Although you were machining down to a diameter, all your measurements were referenced to the centre of the piece and you were taking cuts off the radius. ie. If the piece diameter, which is what you were checking with the micrometer, is 10 thou over and you take a 10 thou pass, the piece diameter will now be 10 thou *under!*
Ps. I didn't see any soft packing where the threaded portion was being held in the chuck. Not best practice if the thread is important.
I was working on a lathe with a direct reading dial on the cross slide, so there is no need to correct for radii vs diameter. Most lathes are like that, save a few old South Bend's.
The stock used in the demo was pulled from the scrap bin but yes, protecting a finish machined surface is always an option.
Hey Tom, Hope you are okay man. Missin my Tom fix.
sdjb111
Still here, just doing the summer thing.
See you in the fall.
Tom
You can walk with a wooden leg , but you can't see with a wooden eye.
But you can still pound some arse with some wood!
Ive got lathe envy for sure, all those cuts go waaaaaay slower on my 1920's machine.. ;)
Ill get an upgrade one day.
Yeah, 1920's cutting tool technology wasn't what it is today.
Thanks for watching.
Didn't you mess that up at the end and go undersize?
"Undersize" is a relative term. Real parts have tolerances associated with them and as long as the dimensions fall within those tolerances, they are good.
Tom
Thankyou for your speedy reply. I appreciate you were only 1/2 a thou under but you miked the diameter and noted you only had 12 thou to go. When you put on a cut of 12 thou you took off 12 1/2 thou. Suppose this was a piston which had to be 1,125 and you wanted to lap off the last 1/2 thou or so. How do you make sure you dont cut a 1/2 thou too small without creeping up on your chosen dimension by taking smaller and smaller cuts? Is there a way?
I only ask because quite often I end up taking smaller and smaller cuts as I get towards the size I need and it takes a lot of time. I think it's also not good for the tool to take tiny cuts.
Thanks for any help you can give.
If I really wanted to hold the nominal dimension I would have taken the last .012" off in two cuts. That way each of those cuts would be identical, and the first one would provide the opportunity for a careful measurement to dial in the final cut.
Measurement teach me pls
I have my safety glasses and my mask on!
TOM: U were off when you set the dial at ".096" and not ".104"
John
No John.
You have to realize that the numbers on the dial are relative, depending on which side of zero you are working. I set the dial to zero and turned it .104" counter-clockwise, ending up on .096". Turning the crank clockwise back to zero advanced the tool .052", taking .104" off the diameter of the part.
Tom
on my lathe .104" should be divided in half
Some Atlas and old South Bend lathes are like that, but most lathes have direct reading dials. You have to know your machine.
Tom