The thing that made this so useful wasn't the tweaking of the lathe feet, but having the explanation of WHY I need to do it. It was very, very useful to see all the places flex and twist can manifest themselves. Thank you for sharing your experience.
Thank you!!! Your video helped me soo much. Second shift crashed my lathe and didn't tell anyone. After your video I was running in about 2 hours. Thanks again. Steve B
You didn't bore me to tears. I'm not a machinist but last Friday they asked me to machine an alignment rod that would be 3.234" diameter and 36" long on the lathe which I figured I could do. Well it didn't go so well and turned into a royal pain. I managed to get what they needed by adjusting the tailstock but tomorrow I'm going to use your method of leveling and then proceed to realign the tailstock. The lathe I'll be working on is a newer Jet 16x50 that looks very much like your lathe. I'll let you know how I did.
I am new to the wold of machine work. Some of the mathematics are over my head but not boring. I compare the machines to the pool playing I used to do. Geometry and physics are more detailed than most would expect. By studying your videos I am learning little by little and I appreciate all the help. Keep teaching and I will keep studying. but I am never bored, Thank You very much. J.D.
I have a Taiwanese manual 10x24 sold by Jet back in the 80s. It was new in the grease when I bought it in the late 90s. I'm still learning. I saw this setup video and put a 10" x 1 3/4" round 6061 piece and did as you showed. I feared the worst because I had disassembled it to get it in the basement in 2001. I don't recall any alignment keys when I put the headstock back on. A 1" test bar between centers helped align the tailstock. When I did your method today, the difference over 7 1/2" of the 6061 bar was 2/10000! Yes, 4 zeros. I think I have a nice little lathe. Thanks for the great video.
Thanks for posting this video with all of the annotations. I recently purchased a 12X36 lathe and will soon be leveling it. This is just what I needed to know to properly align my lathe.
Hey Tom- I remember starting off woodworking where 1/16" was accurate... Then starting metalworking where we broke an inch into a thousand... Cool I thought- Then we are introduced to the thought of breaking an inch into ten thousand.. That's when humility kicks in and we stop using phrases like "perfect". Metalworking can indeed be very humbling... Thanks for another great lesson...
Hey John, Well I've been humbled by treewood a few times. It takes the same attention to detail to do good work in pretty much any trade. Tenths are pretty humbling chasing them about all day long. Cheers, Tom
A sixteenth is fine for carpentry. But when I do fine work, joints need to fit exactly. So I set my woodworking equipment up with my metalworking metrology tools. It’s a myth that fine woodworking is a lot sloppier than metalworking.
Great video, Tom. I remember finding all these papers after my uncle passed with all these different measurements. Later I would find out this is what he was doing. I never got the lesson from him but this is some primo knowledge. Thanks.
Hi Ryan, That is really cool you found your uncles measuring sheets. Do you still have them? It would be fun to look at them. Thanks for sharing. Cheers, Tom
Thanks for the detailed explanation of this procedure. Admittedly, I do not own a lathe, but do enjoy learning about all things machining and hope to "dabble" at some point in the future. As a certified aircraft mechanic who specializes in precision rigging of flight controls, however, I can certainly appreciate the precise nature with which these machines are adjusted. Cheers!
Thanks Tom. I am 65 and just starting this hobby. I have read that lathes are set to turn faces very slightly concave rather than convex, but do not know how this is achieved. I guess on your nice looking machine it is done with the carriage traverse. I am in UK and my, err, import, seems to have a pronounced taper at present. I am checking levelling having watched your very good videos on the subject. Wish I had been able to buy a Myford but decent ones now sell at around $7000 pre owned. The hobby is much cheaper your side of the pond! Thanks again Tom for taking the time to respond, this time I'll try and remember to sign off! Bob.
Robert Hawtin Hi Robert, Concave and convex are maybe not quite the right term although it does describe the shape sort of. If the cross slide is not exactly perpendicular to the spindle axis the cut will produce a very slight cone (convex) or a very slight depression (concave) both will have relatively straight surfaces like a cone or taper as opposed to a radius which is the true meaning of concave or convex. Hope this helps. Best, Tom
Outstanding! I've set up many machines before but never a lathe. I was always curious about it and you did a fantastic job of explaining how it's done. Thank You for taking the time to explain it so well!
Tom, I just purchased a 16x40 mazak mate that was taken apart for a repaint and the guy never got around to finishing it, so this video (that I first watched when you published it) is going to be great help to me;) As always, Thanks Tom, Mark
Mark Schuster Hi Mark, Cool beans. Shoot me a picture of the machine as you put it back together. Nothing like a big mechanical puzzle to keep you out of trouble. Thanks for the comment. Cheers, Tom
Thanks Tom for the "long boring video". It was very informative. When I set up my small 11" Logan it still took me 4-5 hrs. Our Queensland is named Cinder and she is a sweetheart. Great dogs. Thanks again for the video's, maybe one day I will be able to join the You Tube group.
Your concern was unwarranted - this was not at all boring and may have saved me a great deal of trouble. I'm about to disassemble a new lathe and move it to the basement and wanted to check it it's before disassembly state of alignment so this was just the ticket.
Outstanding videos. I really liked the tutorial on the levels. Going to send some quality time with my 13" south bend and machinist level! I can't thank you and Keith, Adam and Mr. Pete enough for sharing your knowledge.
Hi Duncan, I was wishing Chuck was around. Most of these things go better with a helper to read the instruments or make adjustments. Its also a lot more fun. Cheers, Tom
Hi Tom ! In fact I woke up in the middle ... and I hadn't seen a lot of what was going on - but that's was NOT your fault ... I was up very early this morning because of some stupid birds fooling around on the roof ! I just need these aligning methods on my old lathe, so I'll see the video again - at least one more time and get a method writen down for use another time ! That's exactly this kind of instructional videos I love to see and get clever of ;-)) Thx for showing !
oxtoolco Ha, ha, yeah, it seems like they don't want to get "in line" right now - but I'll make my lathe do it ! - but today I'll finish my ... sorry ... your Tailstock Stop on the mill, I beleave ;-))
Hello there TOM Watching this the second time round 'cos we need get our Lathe cutting right and it's driving us crazy as well. Like U said, it has to be done, albeit painstakingly, and we sure have a much better idea now, with a good dose of confidence boost. Now to get 'er done, like the Man says !!! Thanks again for taking time out to show and share. ATB aRM
I always show students this method after aligning the bed with a level. This is what I have been teaching for years and i call it the 2 collar test. I would also recommend putting a mag base and indicator on the tail-stock end of shaft and move the bed and watch the indicator. move it 1 to 1. Most would think you split the difference but it's 1 to 1. Good show. The only time I would move the head is if it is an Asian lathe or some English lathes that have a pivot under the head if it sets on flats and not a V and flat bed. Richard King
Thanks for the video Tom. I happen to have one of those yee olde South Bend lathes from 1948 I'm playing with. I've been playing with it and trying to get it level and all the twist taken out of it so I can use it to repair some old tractor parts and make bushing drivers and the like. I don't have all the fancy dial indicators and high precision measuring devices, so knowing out to level it using a piece of round stock and some micrometers helps.
Thanks Mr. Tom. This is invaluable information. I fought that a taper was created only by the tailstock. I am confident that I will now be able to set up my lathe properly. Warm regards.
Great video Tom. It was very informative. This is the exact same adjustment I plan to do with my Victor, as I have had taper problems with it for a while now. I played with it once, but never tore into it completely to find out where all of the adjustments are made. Maybe some content for a future video. Thanks for sharing bud. Adam
Hey Adam, Let me know if you need to borrow a 14mm allen key or socket. I had to buy a couple for this one job. Yeah put that gopro on your head so the viewers get an idea how much you go back and forth. Talk to you soon. Tom
I bought a 18x60 jet 15 years ago it had been setting unlevel for a couple of years it took about 3 months to get to a point where it quit moving and stayed level, I checked it the other day after watching your video and it needs a little adjusting but I'm about to move it so it can wait until then, good video tom.
Great video Tom! Sometimes the most important things in this trade may come off as boring, but they are very important. I ran into a situation where I was re-leveling the lathes at work and could not for the life of me after lots of adjustment figure out why it still tapered. Then it dawned on me....check the removable bed gap. At first feel the transition felt "fine". After further inspection and some indicator work, found that the gap bed had been removed, but then replaced hap hazardly. After even more work of cleaning out the mating surfaces and re installing the gap and some inspection, some one at one time crashed the machine. They tried to "fix" it by hand grinding down the high spot on the mating surface, which was not so precise. In the end I had to shim it all into place and got it straight. So now the handy feature of a removable gap bed is no longer removable. What did I learn? For some, things are "good enough". Ps.....good enough can always be made better!
thank you for the vid. I am buying my first lathe soon and was wondering how to level it properly. I grew up in a shop as both my grandfathers were engineers and looking forward to having my own. thank you for all the videos
Hey Tom! Well, i´m sure this was a distress for you, but i´m also sure you helped a whole bunch of people in particular me. We have an old Colchester Triumph lathe at the shop with the same kind of a problem. Everyone told me the same argue that it´s just a mangled up machine, dedicated for the scrapyard. finally i´ve got the confirmation of none-ability. I bet everyone want´s you to be his coworker haha Thanks for the Video! Sincerely regards from germany, Simon
Hey Tom, I've been enjoying your videos for quite some time and figured the least I could do for all the effort you've put forth in making such informative videos is to leave a comment saying thank you, so,Thank You sir!! Wish you were close to Texas so I could buy you a beer and try and talk you into stopping buy and helping me get a few things set up so well. ;) Love the videos Tom, keep em coming!!
My 13x40 is off .019" at 7". Thanks for this video. I tried to set it by the leg mounts to no avail and wasn't sure how to proceed. You have saved the day.
oxtoolco I messed with it and got it to .002" at 10" so far. That's the best with adjusting just the legs. Going to try adjusting the head to ways. Thanks
thanks again Professor Tom, i cant say enough for all of you who are taking the time to make these vids, and teaching those of us, 3000 miles away. great stuff for sure. the only question i have is what about your chuck? and may it be out of alignment? if so where would you start machine or chuck or would the tool cutting the piece negate that? just an fyi, im absolutely new to machining in general, and just 5 days ago, finally got my first lathe, and she needs all kinds of love. thanks again for everything!
Hi Dj, When you take a cut all the eccentricity that your workholding may have comes out. It cuts about the spindle rotation not the workholding axis. This is the reason for taking a cut. Thanks for the comment. Cheers, Tom
I assume that you were pleased with the outcome with the alignment so far. The key was to rotate the spindle head on the horizontal plane (yaw axis). Depending on the main work area of the lathe (heavy work pieces etc.) the wear and tear might lead to another misalignment: The head “sinks down” at the spindle side. That means it is lower than supposed to be and resulting in the same taper on the test piece. This wear is usually hard to fix. Your way to measure the misalignment is quite precise and easy to do. I’d suggest taking a longer rod - e.g. 30 inch long and 2 inch od and turn a taper on one end. Align the tailstock with that, so that the tips meet perfectly. Then have the rod stick out to the full extent. It should not wiggle when turning it. You might want to fix wiggling with a 4-jaw and shimming. When it runs true, it should still point perfectly to tailstock tip. If the alignment is really bad you can see with the naked eye that something is crocked. Dial indicators give you more precise hints. You probably get the idea here. Main benefit is that you can keep this setup while adjusting and you can see instant effects on the indicators. So if you turn your head around the yaw axis you can read the effect in the same time.
Hi Tom, Very informative as always. From the numerous comments bemoaning the conditions of lathes, it seems certain a person could make a tidy living becoming a "machine tuner", much like a piano tuner. With experience usually comes proficiency, so instead of a machinist spending six or more hours the tuner could do it in half the time, or less. Also by spreading the cost out over numerous machines, the tuner can afford to have multiple precision levels, indicators, etc to make the job easier and quicker.
Hey Morris, With modern machines technicians from the factory to the fussy setup so the machine performs as advertised. There are quite few folks that make a good living doing machinery repair and troubleshooting. As a shop owner you rarely want your top machinists fooling around leveling machines or diagnosing electrical problems. Problem is these guys are always busy when you need them. Cheers, Tom
One good suggestion, especially with an older lathe is to first check your bearings are all tight as supposed to before doing any test cuts. Have seen one guy chasing his tail with the measurements until another worker came by, toom a 2x4 and lifted the chuck with a dial indicator on it. Chuck showed a nice 0.1 mm lift and sure enough, bearings had to tigtened a whole lot to get the lift to zero. After that adjustment all the measurements were bang on.
Not so much for checking loose headstock (haven't seen that one yet), but to see that the bearings have a proper preload in them. If the spindle/chuck lifts even a little, the bearings need tightening. This check has to be done when the machine is warm, otherwise it can give a bit of a false reading. And if the bearings are tapered rollers, they can be tightened a little on the negative clearance side. If the are not (smaller lathe or something), then negative clearance is not such a good idea.
+Mert Silliker Hi Mert, Glad you liked the video. You haven't lived until you setup and level one thirty feet long (10m)..... Thanks for the comment. Cheers, Tom
Great video as always. Funny timing, I did this very thing last night with a 2.5" bar about 10" long, hadn't seen the video yet. Started out about .003 larger on the tail end, stopped playing at .0003" difference. Such little adjustments needed. Keep making the videos!
Hi Tom, I have a Precision Matthews (Asian) 14 x 40 large bore. Overall a decent machine and I finally gave up waiting to find a decent 13" or larger used machine in the area (Denver). I was actually watching your video on inserts and grinding the multi use tool and the thumbnail with the chuck and the 2.5 bar stock caught my eye and it was somewhat like watching a replay of myself last night but I was happy to not have to move the head.
I have seen this bed ways alignment video and your tailstock alignment video but I dont see a headstock video. Is it titled a little off maybe? I have a lathe that is cutting about .0002 taper on 12" so happey there. But I'm getting a pretty bad .005 taper when facing. My thoughts were I need to adjust the head stock. Would love to see your take on it
So, if you have a smaller lathe using the "suggested" set-up of 3 point contact, 2 under the headstock, 1 under the tailstock, how do you adjust the tailstock end? If you adjust a single screw, are you not just moving that end up and down?
Hi Russ, The three point contact is only for the initial plain leveling of the machine.After the machine is level then you bring all feet into bearing with the floor. Only after this can you start the test cutting and fine alignment work. The single point is placed on the visual center of gravity of the tailstock end which is typically between the two levelers. Cheers, Tom
I've had to align a few 3 axis CNC machines in my day and I know how you feel when you talk about the mind bending frustration. You can start to get a little batty after a while. So how many hours did the whole process take you? And does the temperature in the shop effect any of the alignment? Great vid as always, Jay
Hi Jay, Total hours was maybe six. It took about a week because of needing some tools and other stuff I was working on. Temp is not an issue at this level. everything in my shop is about the same temperature so its kind of mute. Cheers, Tom
OH boy, as soon as I read the title I had a deja-vu moment. Unlike old lathes where the headstock was laid on extended v-ways most new units with gap beds seem to have the adjustable headstock. I had this exact same gremlin with the new lathe. Carefully levelled but yet still cutting a pretty severe (.002" in 2"piece) taper. Finally figured to do the head alignment and all was well. It' is worth anyones time to do the checks for head alignment as it may save you some headaches chasing tapers. And to make it all better I'm going to have to go through the procedure again when I move the machine soon.....:-( Great video Tom...brought back a horror story for me...LOL Colin
oxtoolco I wish I had your video BEFORE diving into that last year. I just went on guts! I may video the next session once the machine is set up in the new location.
Hey Tom, i remember dealing with this problem on a big Tos cylindrical grinder, the bed was in bad shape so had to use a dialindicator to adjust the machine it was a lot of times very frustrating job to make a long perfect cylinder with no taper, on modern machines lathe, mills, grinders it can be set up perfectly with time and patients, cheers from romania.
Hi Andras, Thanks for the comment. The work is easy on good machines. The trick is finding one that is really good and well set up as you mention. Cheers, Tom
Hey Tom I did NOT enjoy this video because I was hoping to be there in person :(. assisting and learning...NOW with that said I know why I wasn't there because of the tedious work required and having me there would be a distraction not an assistance! Great video!...I have read many different articles on lathe leveling...the "Rollie method etc..... My worn lathe cuts a taper and my mentor Chui had showed me and assisted me in getting the best from my machine using this method that you showed. FYI...I had to tie down one of the tail stock feet to the concrete because when I pushed up for the twist the complete foot end of the lathe would lift, the attachment to the deck gave me that slight twist required. Thanks for showing....great instruction Chuck
Hey Chuck, You can bet I'm going to lure you up here the next time I need to do this. Beware if I say something like, Gee Chuck I have a whole bunch of extra tooling and material you might be interested in. If your smart you will be busy. Cheers, Tom
Thanks for the set of lathe leveleing videos. I am now getting to level my 12" clausing that I have been rebuilding since Dec. I hope that I will be able to get some test cuts done by this weekend. The good news is that the leveers for the bed are up on the base, so at least I won't have to do as much crawling around as you had to on the "Sweet potato". Of course I don't think I'll get the old girl cutting as well as yours though. I think if I can get it down to .0005 in 6 inches I'll be pretty happy. Keep the good stuff coming :)
Interesting. Is there a similar method when setting up a mill or once level is it just a case of adjusting the head to perpendicular in each direction to the table each time you adjust it? I hope that makes sense. a drawing would make it easier for me to explain what I mean.
Hey Brick, Mills don't have the same sensitivity as lathes. Normally you compare the head alignment to the table surface of the mill regardless of gravity. Hope that makes sense. Cheers, Tom
Do you have a directors cut of this video. Im missing the part where you did the head-stock alignment and how you verified with the dial gagues. I guess you could just theck the difference between the meeters to get the delta to what you want, or?
Hi Lars, You must be looking for some punishment. There is not much to see except me running back and forth from behind the lathe to the front to look at the indicators. They move so little it doesn't make very good video. So I had my starting point with the indicators and then adjusted the headstock so the net change brought me into alignment. As it turns out they both moved 125 microns or so away from the initial zero position. But the difference between the two was what I needed to make the headstock parallel with the ways. Hope this helps. Cheers, Tom
Hi Tom. Very helpful about checking level calibration. Do you think lathe headstock was over set too much to start with in order to ensure lathe turned faces concave rather than convex?
Robert Hawtin Hi Robert, I think the lathe had not been used for anything long for some time. It had probably been moved several times since the last time it was adjusted. I do not believe it was an intentional offset. Thanks for the comment. Cheers, Tom
Hi Tom, very nice presentation. You aligned your the lathe on the vertical plane, how about the horizontal plane? I had to do just the same you did years back and I thought I am nuts to take the head stuck off the bed. Also I found under the head stock brass shims. I assume they are there for the feature scraping, to lower the head stock or just correct the angle against the bed. Thank you shearing all your insides. Radu
Hi Radu, I don't even want to thing about the horizontal plane. That is going back a ways to access any adjustments. Thanks for the comment. Cheers, Tom
Hey Tom, thanks for the videos! just curious...i have a bench size lathe and i don't have any jacking screws, could i chuck a nice chrome piece of round up, indicate it in, and then do a sweeping indicator reading off the compound rest to measure taper? Hopefully you know what i mean.. Thanks!
Thanks for the video to go with ice cream on this Sunday evening! You are right about twist and flexing bolt tensions and jack screw pressures and all the fun stuff that goes with adjusting the alignment. I love to talking to mechanics about alignments only being math problems, even though I have lived the experience of the for mentioned! I work alignments as a ratio, in addition to the two indicators you used, add two more at the jacking points. formula; using the length between forward and rear jack screws or jack screw span divided by double spindle indicator span equals ratio. Ratio times the movement needed on your choice of jack screws. When I tear down my carriage to make and install a new nut and screw I may take a look at my spindle alignment too! That was a great subject matter! Tom Cheers, Keith ;{)-----
Hey Keith, Thanks for the comment. The jacking arrangement on my lathe is lets just say jacked up. There is no good pivot point to help with the process. I ended up moving it away from the jack points so it could pivot enough to bring it into alignment. I tightened the snot out of the big holdown bolts in the hope I won't have to do it in the near future. The ratio approach makes a lot of sense. Looks like I need to buy a couple more indicator bases. Yipppee more tools. All the best. Tom
Hey Bill, Remember the pipe I use for the rod bender? Well that's the snot part of this operation. Guessing here at around 200 lb/ft with that arm. One oxpower was used which is equal to 5252 lb/ft min. Cheers, Tom
Tom you ended up moving the head stock itself to correct the taper in this video. If the headstock wasn't level with the ways would it have resulted in the same issue? Is there a similar adjustment on a lathes' headstock for that alignment or is that in the ways themselves?
Hi Hank, There is no adjustment for up down just side to side. I guess its easy to make the spindle bore parallel to the base of the headstock casting. Cheers, Tom
Hi Tom, it's a bit late for my comment , i started watching all your videos from beginning. When I was in school 20 years ago they says that the overhang in the chuck can not exceed 3 times the diameter of the part, or you have to use the tail stock to support it, that's to prevent a small flex and vibrations in the part. Can it be that 0.001" difference comes from this vibration? Is this a true statement? Thanks. Bobby uk
Hi Bobby, For regular turning you are correct. This is a special case where we want the most separation between the turned bosses as possible. If you watched the video I just barely took a cut on them. The bosses make it so you do not have to cut much material at all. The large diameter is stiff enough so the push of the tool is not a factor. Thanks for the comment. Cheers, Tom
In accordance with South Bend, Clausing and Cincinnati Lathes, for this to be accurate you MUST turn the shaft between centers because this gives you a more accurate measurement of the twist/off-level of the lathe. Where can I find any writeup about using a chuck and no tailstock?
+Gilberto Diaz Castro Hi Gilberto, Better check your references. How do you know any taper is not caused by the tailstock being mis-aligned? Most tailstocks read low when swept with a test indicator. Which is hard enough because of sag of the indicator and support arm. Thanks for the comment. Cheers, Tom
Seems like we both are on the right track once we look at the different objectives. The method you explained endures the ways and the spindle are aligned, the method explained be South Bend and the others verifies that the tailstock is aligned to the ways... I gather the head alignment should be done first since it requires leveling the bed, then all is left is to verify the tailstock alignment... Now to see how my TrayTop is doing... Thanks.
Hi Tom, I wish that when I align my lathe it will be as easy as when you did yours, fall asleep in the first 15 seconds and then when I wake up 42 minutes later and it's done...! Yes... Well done video, everything to complete successfully the task is there. All I have is a garage Cat called ''Gros-Tata'' (It's French) He rushes out when I show up and scratch at the door when I leave, he doesn't like the noise of the machines, he FREAK'S out. Cheers, Pierre
This is, by far, the most useful bit of instruction I've seen about setting up a lathe. On behalf of my old Logan, thank you! Forgive the silly noob question, but why cut a chamfer in the test bar? Does it help keep the feed-in more accurate on the first cut, or is it just 'good practice?'
+Hessian Deiter Hi Hessian, No particular reason for the chamfer other than attention to detail. It does provide some lead in for the tool but its negligible. Thanks for the comment. Cheers, Tom
Hi Bill, The sequence is Level, Twist removal, Headstock alignment, then finally tailstock alignment. Tailstocks have a nasty habit of not being where you think they are. This is why I prefer to keep it out of fundamental alignment of the machine. Cheers, Tom
This was very educational, it makes you wonder how much work goes into making machine tools and making them accurate and consistent. I don't fully understand how you knew that you got all of the twist out of the bed and needed to adjust the headstock? How long did the whole process take?
Hi Tyler, The whole thing took maybe six hours. It was over the course of a week. The measurements show basically no change going from level to not level and loaded at different points. What I mean is the leveling feet had no real effect on the cutting conditions. Cheers, Tom
Instead of doing the test cuts could you chuck up some precision bar and with a dial indicator on the tool holder check for taper both up/down front/back ?
Hi Lasse, There are some methods with very straight and accurate test bars. This requires more careful setup than the test cuts. What we care about is parallelism of the tool to the axis of rotation. If you don't rotate then it introduces other uncertainties to the measuring. cheers, Tom
Hi Aw, If you had a known test bar and could hold it straight then it would work. The test cutting is by far the easiest and most foolproof method to check for lathe mis-alignments. After all we ultimately care how a machine cuts. How do you qualify a test bar in your shop? You need to check for straightness and cylindricity to understand where any measuring errors come from. You need to make sure you take your measurements along the centerline of the bar as well. Not always an easy thing to do. Cheers, Tom
oxtoolco We have a pretty decent inspection room here in our shop. I guess what I meant to ask is if your machine is cutting a taper how can you tell if it's out of level or if the head stock is out of square. BTW, I heard you mention Hayward in one of your videos. I work in Fairfield for the Ball Corporation :-) Thanks again. Sonny
Hi Sonny, I would start by precision leveling the machine to see if you can eliminate your taper problem. If you see little to no effect much like I did in the video then take a look at headstock alignment. The point it to be careful to not introduce another source of error from the wrong place. Cheers, Tom
Re 35:30 Truing up side to side. Why not set the tail stock rigidly in place to hold that end fixed? Then your head stock adjustments will only affect the chuck end.
Hi Ryan, You can't have the tailstock influence the test cutting. It has its own set of alignment errors that confuse the readings. Thanks for the comment. Cheers, Tom
So regardless how trued up the tail stock is, even if it is absolute perfect, you don't know for sure that it isn't throwing a variable into the works. That makes sense. Also demonstrates your long term experience with lathes and these issues. In watching these videos it's absolutely unreal how many tricks, tweaks and little nuances experts like you know. Reminds me of when I was learning motor winding and my buddy, a winder of 40 years experience, told me, "It takes about 5 years until you are smart enough just to not ask stupid questions."
hi I like your videos and been very helpful. I had a query, when I am turning a shaft, both end of Shafts are quiet OK, but the middle portion of shaft gets tapered. can u pls guide me.
Hi Tom, Wow, not boring at all, highly informative, I would have had no idea what would be involved in that process, I can easily see how tedious and frustrating this could be. I think I would be afraid to do such a test on any of my lathes for fear of having to slog thru such a procedure, and in my case, excavating would be involved as well. Excellent informative video .... Mike
Hey Michael, You might save some work tunneling in from the outside. Come up right under the lathe to adjust the levelers. If it aint broke don't fix it is a good maxim here. Cheers, Tom
Just thinking here about a method of confirming if the load on a pair of feet is equal and I've been thinking about this since I heard the ring when tapping on one of the feet. Long sentence but I wonder if the change in the ring is relative to frequency, load on foot, and if that change in frequency can be measured with an app. There's more to this but there must a long term stability benefit in carefully balancing the load. Thanks for the interesting video.
Hi Colin, Not really. What we need in the test bar is the ability to discriminate the difference in diameters to about the limit of our measuring ability. A longer bar gives us better resolution but at the expense of a much larger size as it needs to be unsupported by the tailstock. Cheers, Tom
Ok I understand the accuracy you're trying to achieve but for a backyard turning operation dose it really matter I mean what's the accuracy of the mating face?
+Jerry Halcomb Hi Jerry, Not all lathes have adjustable headstocks. Be sure you understand your geometry problems before you suspect headstock misalignment. Be sure the machine is level and straight first. Thanks for the comment, Cheers, Tom
Yea your not twisting it much if any! Years ago I battled with a fairly large hollow spindle lathe, 9 1/4 bore, that cut a taper and we were constantly messing with the tailstock to try and compensate Finally figured out the headstock was off and it turned out all the bolts were loose and the adjustment screws that moved the thing on the gear end that are supposed to lock against each other and then had jam nuts weren't even tight against the block........ Yea it takes a while but once I got it sorted it was a whole different machine and a joy to use!!!
Hi Gent, Even as long as this lathe is I only got a couple tenths. I can feel you on the big lathe. Compensating for a jacked machine is a royal pain in the neck that you rarely have the time to fix. Cheers, Tom
Hi Tom. Another great vid! Was wondering.....Have you assumed your bedways are not worn in the vacinity of the chuck. I was thinking potentially the nearest way could be worn say .001 , in a saddle shape, which would set you off chasing your tail from the beginning as it would show maybe .0015 or more on the test diameter.
Hi Nick, This test gets you as close as you can be with the machine you have. It does not cover the entire length of the machine. When we look at the overall length the tailstock comes into play and that is a can of worms all by itself. Thanks for the comment. Cheers, Tom
Great information Tom. Newbie question most likely, how sensitive is this process to the chuck installed - I imagine your lathe is now 'calibrated' if you will to the 6 jaw. I imagine if you have a 6 jaw you are only likely to switch it out with a 4 jaw where you are going to have to dial in over the length anyway, but if you say had a collet chuck how close do you think your taper results would be?
Hi Steve, The workholding is not part of the test. We are measuring about the axis of rotation. Imagine if the test bar was running out .010. Once we cut it to a full cleanup that cylindrical surface is coaxial with the spindle rotation. I would not expect any difference in taper switching work holding gear. Cheers, Tom
Hello Tom Great video. These problems can be a real pain to rectify. The spindle bearings can have a lot of influence on tapers as well. They can lift to different heights depending on RPM. Even belt tension and cleanliness on units without headstock gearboxes (CNC mostly) will affect taper in my experience. A question, my main concern was when moving the headstock so much did it affect the flatness when facing? It doesnt take much to make a big change there. Cheers
Darren Wright Hi Darren, Yes it did. It improved it as you might expect. Facing flatness is actually difficult to check on the machine. Thanks for the comment. Cheers, Tom
Hey Rick, You would not be comparing the carriage travel to the spindle axis with the faceplate method. We are trying to eliminate errors in parallelism between the spindle and carriage travel (ways). Thanks for the comment and suggestion. Cheers, Tom
Rick Brandt Hi Rick, How do you assure the faceplate is flat? You can't use the machine to inspect it. If you face it then measure it could be some conic shape. The beauty of turning a test shaft is it exposes misalignment or twist directly and in an easily measurable way. Best, Tom
Actually, you should loosen the jacking screws after you tighten the headstock bolts. You want the headstock to move if you ever have a crash. If things can move, they are less likely to break.
Hi Wes, If you loosen the jacking screws the headstock would shift. Its kind of a push pull arrangement. Its not designed as a safety measure for crashes. Thanks for the comment. Cheers, Tom
Yes, the push/pull screws are the ones I'm talking about. The headstock should have a center spud or hub that allows it to rotate in what would be the Y axis. There will be a pair of push/pull screws that let you adjust the rotation. Mazak and Mori call them "knock bolts". Other lathes have no spud and use 2 pairs of knock screws. I recommend that you leave them loose. The headstock bolts will hold the headstock in alignment. Like I said before, you want the headstock to move in the event of a crash. Every manual I have seen recommends leaving them loose after the alignment is achieved. Some lathes have jam screws that you can used to raise each corner to align the spindle in the vertical plane. Obviously you can't leave those loose. That's not a great design though since the bearing area of the jam screws is so small.
It doesn't matter. Some CNC lathes have no spud and use two sets of jacking bolts. I guess you're committed. It's your machine... You also need to realign the tailstock after moving the headstock.
Hi Wes, Its not that I don't believe what your saying is correct for some machines. The YAM manual clearly says "After obtaining the proper alignment, tighten the fixing bolts, then tighten the six hold down bolts" After screwing around with it for a few hours I'm not touching any of them. I'l risk any potential consequences from a crash. Thanks for the comment. Cheers, Tom
I have levelled my lathe , following the video and it cuts great. Now, the coolant flows the wrong end of the bed, away from the drain/pickup area, towards the headstock.Any ideas?
Hi Sky, Well is sounds like the position you found is not particularly level. I would suggest that you can find another position that the machine cuts well were your coolant will drain properly. The goal is to be as close to level as possible with the machine cutting properly and bearing on all the support points. Thanks for the comment. Cheers, Tom
Silly question as I didn't see anyone ask or mention it in the first 30 or so comments, could some of the taper you were chasing be caused by worn bed ways? We have several old(er) machines where I work that will cut taper up by the chuck where most of the work has been done, and cut straight further down the ways... This with exception of the lathe that has pretty much only turned shafting, which has fairly consistent wear for the length of the bed.
Hi Ice, This lathe has hardened bedways which appear to be in good shape. You would have to do a much longer sample to expose and diagnose that kind of a problem. This was pretty clear case that the headstock was out of alignment. Cheers, Tom
Hi Jon, You are right it would be better. The bar has to be self supporting without a center in the free end. So to do a 1m bar it would need to be 200 or 300 mm in diameter. Cheers, Tom
Thank you. This video really helped me out. I used a tube instead of round bar was the only difference. The headstock was out on mine about .006 was able to get it to .0005. Not perfect but a lot closer. Thanks again
As you may know Im back in my machine shop after watching you and fenner' I bought a new 8 in starrett level to check my enco 13 = 40 lathe that i never leveled and it was out so i got it pretty plumb and level and then did the two ring cut test and i was happy to see it was at most two tenths of a thou out in ten inches.
hey tom , am doing my under graduation in mechanical engineering and i kind of like machine shop very much because you can show your way of creativity and art, the engineer's way....And I kind of learn a lot from your videos ,those little tricks help me a lot in my college shop ..... so am much obliged for that..... (thank you) x (n) - for the upcoming videos and the past videos and I saw in one of your videos , you have a marking up the viewer in the world map kind of stuff ....so I would like to see If any one is from INDIA if not I would like to be the first one ....
Hi Msshyam, Thanks for the nice comment. We do have another viewer in India I think in Bombay. He has a shop there I believe. Best of luck with your engineering career and be sure to learn as much about how things actually get built in the shop. It will pay you back a thousand times. I put you on the list for a pin when I get back to that. Cheers, Tom
I am writing from Oz. I am familiar with the breed, and have had close relationships with some. I was unaware that they had made inroads into CA. It is good to see. Richard.
Tom, I enjoyed the video. I may do this same test on my South Bend 10" heavy. The headstock is not adjustable but the bed has some leveling feet/screw gizmo on the far right end. Eric
Fascinating set of videos on moving, levelling and calibrating a large lathe. Very informative and comfortingly human - well presented.
The thing that made this so useful wasn't the tweaking of the lathe feet, but having the explanation of WHY I need to do it. It was very, very useful to see all the places flex and twist can manifest themselves. Thank you for sharing your experience.
Hi Buck,
Lathes are one of those twisty type machines. Once you can see that the leveling makes perfect sense. Thanks for the comment.
Cheers,
Tom
Thank you!!! Your video helped me soo much. Second shift crashed my lathe and didn't tell anyone. After your video I was running in about 2 hours. Thanks again.
Steve B
Hi Steve,
Glad the video helped out. Always nice when your workmates help you out. Thanks for the comment.
Cheers,
Tom
You didn't bore me to tears. I'm not a machinist but last Friday they asked me to machine an alignment rod that would be 3.234" diameter and 36" long on the lathe which I figured I could do. Well it didn't go so well and turned into a royal pain. I managed to get what they needed by adjusting the tailstock but tomorrow I'm going to use your method of leveling and then proceed to realign the tailstock. The lathe I'll be working on is a newer Jet 16x50 that looks very much like your lathe. I'll let you know how I did.
I am new to the wold of machine work. Some of the mathematics are over my head but not boring. I compare the machines to the pool playing I used to do. Geometry and physics are more detailed than most would expect. By studying your videos I am learning little by little and I appreciate all the help. Keep teaching and I will keep studying. but I am never bored,
Thank You very much. J.D.
I have a Taiwanese manual 10x24 sold by Jet back in the 80s. It was new in the grease when I bought it in the late 90s. I'm still learning. I saw this setup video and put a 10" x 1 3/4" round 6061 piece and did as you showed. I feared the worst because I had disassembled it to get it in the basement in 2001. I don't recall any alignment keys when I put the headstock back on. A 1" test bar between centers helped align the tailstock. When I did your method today, the difference over 7 1/2" of the 6061 bar was 2/10000! Yes, 4 zeros. I think I have a nice little lathe. Thanks for the great video.
Thanks for posting this video with all of the annotations. I recently purchased a 12X36 lathe and will soon be leveling it. This is just what I needed to know to properly align my lathe.
Hey Tom- I remember starting off woodworking where 1/16" was accurate... Then starting metalworking where we broke an inch into a thousand... Cool I thought- Then we are introduced to the thought of breaking an inch into ten thousand.. That's when humility kicks in and we stop using phrases like "perfect". Metalworking can indeed be very humbling... Thanks for another great lesson...
Hey John,
Well I've been humbled by treewood a few times. It takes the same attention to detail to do good work in pretty much any trade. Tenths are pretty humbling chasing them about all day long.
Cheers,
Tom
A sixteenth is fine for carpentry. But when I do fine work, joints need to fit exactly. So I set my woodworking equipment up with my metalworking metrology tools. It’s a myth that fine woodworking is a lot sloppier than metalworking.
Great video, Tom. I remember finding all these papers after my uncle passed with all these different measurements. Later I would find out this is what he was doing. I never got the lesson from him but this is some primo knowledge. Thanks.
Hi Ryan,
That is really cool you found your uncles measuring sheets. Do you still have them? It would be fun to look at them. Thanks for sharing.
Cheers,
Tom
Thanks for the detailed explanation of this procedure. Admittedly, I do not own a lathe, but do enjoy learning about all things machining and hope to "dabble" at some point in the future. As a certified aircraft mechanic who specializes in precision rigging of flight controls, however, I can certainly appreciate the precise nature with which these machines are adjusted. Cheers!
Hi Mutt,
Thanks for the comment.
Cheers,
Tom
Thanks Tom. I am 65 and just starting this hobby. I have read that lathes are set to turn faces very slightly concave rather than convex, but do not know how this is achieved. I guess on your nice looking machine it is done with the carriage traverse. I am in UK and my, err, import, seems to have a pronounced taper at present. I am checking levelling having watched your very good videos on the subject. Wish I had been able to buy a Myford but decent ones now sell at around $7000 pre owned. The hobby is much cheaper your side of the pond! Thanks again Tom for taking the time to respond, this time I'll try and remember to sign off! Bob.
Robert Hawtin Hi Robert,
Concave and convex are maybe not quite the right term although it does describe the shape sort of. If the cross slide is not exactly perpendicular to the spindle axis the cut will produce a very slight cone (convex) or a very slight depression (concave) both will have relatively straight surfaces like a cone or taper as opposed to a radius which is the true meaning of concave or convex. Hope this helps.
Best,
Tom
Outstanding! I've set up many machines before but never a lathe. I was always curious about it and you did a fantastic job of explaining how it's done. Thank You for taking the time to explain it so well!
Hi Barrett,
Thanks for the nice comment.
Cheers,
Tom
Awesome learning in the two videos of this series--thanks so much for making these videos!!
Tom, I just purchased a 16x40 mazak mate that was taken apart for a repaint and the guy never got around to finishing it, so this video (that I first watched when you published it) is going to be great help to me;)
As always, Thanks Tom,
Mark
Mark Schuster Hi Mark,
Cool beans. Shoot me a picture of the machine as you put it back together. Nothing like a big mechanical puzzle to keep you out of trouble. Thanks for the comment.
Cheers,
Tom
Thanks Tom for the "long boring video". It was very informative. When I set up my small 11" Logan it still took me 4-5 hrs. Our Queensland is named Cinder and she is a sweetheart. Great dogs.
Thanks again for the video's, maybe one day I will be able to join the You Tube group.
Woof Woof!
All the best,
Tom
Your concern was unwarranted - this was not at all boring and may have saved me a great deal of trouble. I'm about to disassemble a new lathe and move it to the basement and wanted to check it it's before disassembly state of alignment so this was just the ticket.
Outstanding videos. I really liked the tutorial on the levels. Going to send some quality time with my 13" south bend and machinist level! I can't thank you and Keith, Adam and Mr. Pete enough for sharing your knowledge.
Hi Joe,
Thanks for the nice comment. Let us know how you come out with your lathe leveling.
Cheers,
Tom
As soon as you mentioned moving the head stock knew you were in for it. A helper would have come in handy, yes? Glad you got it sorted.
Hi Duncan,
I was wishing Chuck was around. Most of these things go better with a helper to read the instruments or make adjustments. Its also a lot more fun.
Cheers,
Tom
Hi Tom !
In fact I woke up in the middle ... and I hadn't seen a lot of what was going on - but that's was NOT your fault ... I was up very early this morning because of some stupid birds fooling around on the roof !
I just need these aligning methods on my old lathe, so I'll see the video again - at least one more time and get a method writen down for use another time !
That's exactly this kind of instructional videos I love to see and get clever of ;-))
Thx for showing !
Hey Keld,
Not sure your communist lathe can be aligned. There is no talking to those guys.
Tweet, tweet,
Tom
oxtoolco Ha, ha, yeah, it seems like they don't want to get "in line" right now - but I'll make my lathe do it !
- but today I'll finish my ... sorry ... your Tailstock Stop on the mill, I beleave ;-))
Hello there TOM
Watching this the second time round 'cos we need get our Lathe cutting right and it's driving us crazy as well. Like U said, it has to be done, albeit painstakingly, and we sure have a much better idea now, with a good dose of confidence boost.
Now to get 'er done, like the Man says !!!
Thanks again for taking time out to show and share.
ATB
aRM
I always show students this method after aligning the bed with a level. This is what I have been teaching for years and i call it the 2 collar test. I would also recommend putting a mag base and indicator on the tail-stock end of shaft and move the bed and watch the indicator. move it 1 to 1. Most would think you split the difference but it's 1 to 1. Good show. The only time I would move the head is if it is an Asian lathe or some English lathes that have a pivot under the head if it sets on flats and not a V and flat bed. Richard King
Excellent demo of the test bar, and process of getting the lathe true!
Thanks for sharing Tom,
Ray
Thanks for the video Tom. I happen to have one of those yee olde South Bend lathes from 1948 I'm playing with. I've been playing with it and trying to get it level and all the twist taken out of it so I can use it to repair some old tractor parts and make bushing drivers and the like. I don't have all the fancy dial indicators and high precision measuring devices, so knowing out to level it using a piece of round stock and some micrometers helps.
Thanks Mr. Tom. This is invaluable information. I fought that a taper was created only by the tailstock. I am confident that I will now be able to set up my lathe properly.
Warm regards.
Hi Robert,
Bed twist first, headstock second, then align the tailstock. Glad you liked the series.
Cheers,
Tom
Great video Tom. It was very informative. This is the exact same adjustment I plan to do with my Victor, as I have had taper problems with it for a while now. I played with it once, but never tore into it completely to find out where all of the adjustments are made. Maybe some content for a future video.
Thanks for sharing bud.
Adam
Hey Adam,
Let me know if you need to borrow a 14mm allen key or socket. I had to buy a couple for this one job. Yeah put that gopro on your head so the viewers get an idea how much you go back and forth.
Talk to you soon.
Tom
I bought a 18x60 jet 15 years ago it had been setting unlevel for a couple of years it took about 3 months to get to a point where it quit moving and stayed level, I checked it the other day after watching your video and it needs a little adjusting but I'm about to move it so it can wait until then, good video tom.
Hey Joe,
Thanks for the comment. Let us know how you make out when you re-level your machine.
cheers,
Tom
Thanks for going through all that. I had no idea so much was involved. Makes me appreciate my semester in metal shop a little more
Hi Bear,
Thanks for the comment.
Cheers,
Tom
Merry Christmas and thank you for good, detailed video lesson! I watched from Russia and really happy to see how to fine tune lathe!
Hi Maxim,
Thanks for the comment. Greetings from the USA!
Cheers,
Tom
Great video Tom! Sometimes the most important things in this trade may come off as boring, but they are very important. I ran into a situation where I was re-leveling the lathes at work and could not for the life of me after lots of adjustment figure out why it still tapered. Then it dawned on me....check the removable bed gap. At first feel the transition felt "fine". After further inspection and some indicator work, found that the gap bed had been removed, but then replaced hap hazardly. After even more work of cleaning out the mating surfaces and re installing the gap and some inspection, some one at one time crashed the machine. They tried to "fix" it by hand grinding down the high spot on the mating surface, which was not so precise. In the end I had to shim it all into place and got it straight. So now the handy feature of a removable gap bed is no longer removable. What did I learn? For some, things are "good enough". Ps.....good enough can always be made better!
Hey Eddie,
Best is the enemy of good enough. Thanks for sharing your experience with the gap lathe.
Cheers,
Tom
thank you for the vid. I am buying my first lathe soon and was wondering how to level it properly. I grew up in a shop as both my grandfathers were engineers and looking forward to having my own. thank you for all the videos
PMPC Mining Hi Mining,
You will wonder how you did without a lathe for so long. Thanks for the comment.
Cheers,
Tom
No boredom here Tom, very informative I will definitely be checking my old lathe to see how far it's off..Thanks
Such patience! Level with the Planet! love it, and not boring at all
Hey Tom!
Well, i´m sure this was a distress for you, but i´m also sure you helped a whole bunch of people in particular me. We have an old Colchester Triumph lathe at the shop with the same kind of a problem. Everyone told me the same argue that it´s just a mangled up machine, dedicated for the scrapyard. finally i´ve got the confirmation of none-ability. I bet everyone want´s you to be his coworker haha
Thanks for the Video! Sincerely regards from germany,
Simon
Hey Tom,
I've been enjoying your videos for quite some time and figured the least I could do for all the effort you've put forth in making such informative videos is to leave a comment saying thank you, so,Thank You sir!! Wish you were close to Texas so I could buy you a beer and try and talk you into stopping buy and helping me get a few things set up so well. ;) Love the videos Tom, keep em coming!!
Hi Austin,
Thanks for the comment and viewership.
Cheers,
Tom
My 13x40 is off .019" at 7".
Thanks for this video. I tried to set it by the leg mounts to no avail and wasn't sure how to proceed. You have saved the day.
+newstart49 Hi Newstart,
Phew! .019 at seven inches is almost a morse taper..... Thanks for the comment.
Cheers,
Tom
oxtoolco
I messed with it and got it to .002" at 10" so far. That's the best with adjusting just the legs.
Going to try adjusting the head to ways. Thanks
Thanks Tom. Great video and some great information. I appreciate your videos and have learned a lot from them.
thanks again Professor Tom, i cant say enough for all of you who are taking the time to make these vids, and teaching those of us, 3000 miles away. great stuff for sure.
the only question i have is what about your chuck? and may it be out of alignment? if so where would you start machine or chuck or would the tool cutting the piece negate that?
just an fyi, im absolutely new to machining in general, and just 5 days ago, finally got my first lathe, and she needs all kinds of love.
thanks again for everything!
Hi Dj,
When you take a cut all the eccentricity that your workholding may have comes out. It cuts about the spindle rotation not the workholding axis. This is the reason for taking a cut. Thanks for the comment.
Cheers,
Tom
Thanks Tom, that makes sense, im still learning (thanks to you and all the teachers on here), keep the info coming!
Great video, Tom. I learned a lot from it. Appreciate you taking the time to make it. Thanks.
Hi RW,
Thanks for the comment and participation.
Cheers,
Tom
It may have been frustrating but I learned a lot. Well done and thanks.
I assume that you were pleased with the outcome with the alignment so far. The key was to rotate the spindle head on the horizontal plane (yaw axis).
Depending on the main work area of the lathe (heavy work pieces etc.) the wear and tear might lead to another misalignment: The head “sinks down” at the spindle side. That means it is lower than supposed to be and resulting in the same taper on the test piece. This wear is usually hard to fix.
Your way to measure the misalignment is quite precise and easy to do. I’d suggest taking a longer rod - e.g. 30 inch long and 2 inch od and turn a taper on one end. Align the tailstock with that, so that the tips meet perfectly. Then have the rod stick out to the full extent. It should not wiggle when turning it. You might want to fix wiggling with a 4-jaw and shimming.
When it runs true, it should still point perfectly to tailstock tip. If the alignment is really bad you can see with the naked eye that something is crocked. Dial indicators give you more precise hints. You probably get the idea here. Main benefit is that you can keep this setup while adjusting and you can see instant effects on the indicators. So if you turn your head around the yaw axis you can read the effect in the same time.
Hi Tom,
Very informative as always.
From the numerous comments bemoaning the conditions of lathes, it seems certain a person could make a tidy living becoming a "machine tuner", much like a piano tuner. With experience usually comes proficiency, so instead of a machinist spending six or more hours the tuner could do it in half the time, or less. Also by spreading the cost out over numerous machines, the tuner can afford to have multiple precision levels, indicators, etc to make the job easier and quicker.
Hey Morris,
With modern machines technicians from the factory to the fussy setup so the machine performs as advertised. There are quite few folks that make a good living doing machinery repair and troubleshooting. As a shop owner you rarely want your top machinists fooling around leveling machines or diagnosing electrical problems. Problem is these guys are always busy when you need them.
Cheers,
Tom
One good suggestion, especially with an older lathe is to first check your bearings are all tight as supposed to before doing any test cuts. Have seen one guy chasing his tail with the measurements until another worker came by, toom a 2x4 and lifted the chuck with a dial indicator on it. Chuck showed a nice 0.1 mm lift and sure enough, bearings had to tigtened a whole lot to get the lift to zero. After that adjustment all the measurements were bang on.
Hi Jaakko,
Lifting the headstock with a lever is a good check for headstock looseness. Thanks for the comment.
Cheers,
Tom
Not so much for checking loose headstock (haven't seen that one yet), but to see that the bearings have a proper preload in them. If the spindle/chuck lifts even a little, the bearings need tightening. This check has to be done when the machine is warm, otherwise it can give a bit of a false reading.
And if the bearings are tapered rollers, they can be tightened a little on the negative clearance side. If the are not (smaller lathe or something), then negative clearance is not such a good idea.
watched this video at least several times. very informative, presently trying setting up lathe and it is two man job.
+Mert Silliker Hi Mert,
Glad you liked the video. You haven't lived until you setup and level one thirty feet long (10m)..... Thanks for the comment.
Cheers,
Tom
Great video as always. Funny timing, I did this very thing last night with a 2.5" bar about 10" long, hadn't seen the video yet. Started out about .003 larger on the tail end, stopped playing at .0003" difference. Such little adjustments needed. Keep making the videos!
Hi Mike,
Somebody out there is doing one right now as we speak. Its weird thinking about it. What kind of lathe were you setting up?
Cheers,
Tom
Hi Tom, I have a Precision Matthews (Asian) 14 x 40 large bore. Overall a decent machine and I finally gave up waiting to find a decent 13" or larger used machine in the area (Denver). I was actually watching your video on inserts and grinding the multi use tool and the thumbnail with the chuck and the 2.5 bar stock caught my eye and it was somewhat like watching a replay of myself last night but I was happy to not have to move the head.
Would I need a test bar of similar length to my ways or the travel my tool would make to get accurate alignment ? Just wondering?
I have seen this bed ways alignment video and your tailstock alignment video but I dont see a headstock video. Is it titled a little off maybe? I have a lathe that is cutting about .0002 taper on 12" so happey there. But I'm getting a pretty bad .005 taper when facing. My thoughts were I need to adjust the head stock. Would love to see your take on it
So, if you have a smaller lathe using the "suggested" set-up of 3 point contact, 2 under the headstock, 1 under the tailstock, how do you adjust the tailstock end?
If you adjust a single screw, are you not just moving that end up and down?
Hi Russ,
The three point contact is only for the initial plain leveling of the machine.After the machine is level then you bring all feet into bearing with the floor. Only after this can you start the test cutting and fine alignment work. The single point is placed on the visual center of gravity of the tailstock end which is typically between the two levelers.
Cheers,
Tom
I've had to align a few 3 axis CNC machines in my day and I know how you feel when you talk about the mind bending frustration. You can start to get a little batty after a while.
So how many hours did the whole process take you? And does the temperature in the shop effect any of the alignment?
Great vid as always,
Jay
Hi Jay,
Total hours was maybe six. It took about a week because of needing some tools and other stuff I was working on. Temp is not an issue at this level. everything in my shop is about the same temperature so its kind of mute.
Cheers,
Tom
Enjoyable video. Even as a new (mechanically minded) lathe owner, i thought it was well done and understandable. Thanks
Hi Don,
Thanks for the comment and feedback.
Cheers,
Tom
OH boy, as soon as I read the title I had a deja-vu moment. Unlike old lathes where the headstock was laid on extended v-ways most new units with gap beds seem to have the adjustable headstock.
I had this exact same gremlin with the new lathe. Carefully levelled but yet still cutting a pretty severe (.002" in 2"piece) taper. Finally figured to do the head alignment and all was well.
It' is worth anyones time to do the checks for head alignment as it may save you some headaches chasing tapers.
And to make it all better I'm going to have to go through the procedure again when I move the machine soon.....:-(
Great video Tom...brought back a horror story for me...LOL
Colin
Hey Colin,
Glad to take you down memory lane. .002 in two inches is not misalignment its an angle cut......
Cheers,
Tom
oxtoolco
I wish I had your video BEFORE diving into that last year. I just went on guts!
I may video the next session once the machine is set up in the new location.
Hey Tom, i remember dealing with this problem on a big Tos cylindrical grinder, the bed was in bad shape so had to use a dialindicator to adjust the machine it was a lot of times very frustrating job to make a long perfect cylinder with no taper, on modern machines lathe, mills, grinders it can be set up perfectly with time and patients, cheers from romania.
Hi Andras,
Thanks for the comment. The work is easy on good machines. The trick is finding one that is really good and well set up as you mention.
Cheers,
Tom
Hey Tom
I did NOT enjoy this video because I was hoping to be there in person :(. assisting and learning...NOW with that said I know why I wasn't there because of the tedious work required and having me there would be a distraction not an assistance!
Great video!...I have read many different articles on lathe leveling...the "Rollie method etc..... My worn lathe cuts a taper and my mentor Chui had showed me and assisted me in getting the best from my machine using this method that you showed. FYI...I had to tie down one of the tail stock feet to the concrete because when I pushed up for the twist the complete foot end of the lathe would lift, the attachment to the deck gave me that slight twist required.
Thanks for showing....great instruction
Chuck
Hey Chuck,
You can bet I'm going to lure you up here the next time I need to do this. Beware if I say something like, Gee Chuck I have a whole bunch of extra tooling and material you might be interested in. If your smart you will be busy.
Cheers,
Tom
Tom. Could you use a torque wrench to get all feet down at the same pressure for a baseline to start at?
Thanks for the set of lathe leveleing videos. I am now getting to level my 12" clausing that I have been rebuilding since Dec. I hope that I will be able to get some test cuts done by this weekend. The good news is that the leveers for the bed are up on the base, so at least I won't have to do as much crawling around as you had to on the "Sweet potato". Of course I don't think I'll get the old girl cutting as well as yours though. I think if I can get it down to .0005 in 6 inches I'll be pretty happy.
Keep the good stuff coming :)
From start to finish about how long did it take to level and align this? Or how long would you expect this to take if you weren't shooting a video?
Interesting. Is there a similar method when setting up a mill or once level is it just a case of adjusting the head to perpendicular in each direction to the table each time you adjust it? I hope that makes sense. a drawing would make it easier for me to explain what I mean.
Hey Brick,
Mills don't have the same sensitivity as lathes. Normally you compare the head alignment to the table surface of the mill regardless of gravity. Hope that makes sense.
Cheers,
Tom
So one an older less rigid machine how do you determine if it's twist, wear or head stock alignment?
Do you have a directors cut of this video. Im missing the part where you did the head-stock alignment and how you verified with the dial gagues. I guess you could just theck the difference between the meeters to get the delta to what you want, or?
Hi Lars,
You must be looking for some punishment. There is not much to see except me running back and forth from behind the lathe to the front to look at the indicators. They move so little it doesn't make very good video. So I had my starting point with the indicators and then adjusted the headstock so the net change brought me into alignment. As it turns out they both moved 125 microns or so away from the initial zero position. But the difference between the two was what I needed to make the headstock parallel with the ways. Hope this helps.
Cheers,
Tom
Thanks Tom.
Hi Tom. Very helpful about checking level calibration. Do you think lathe headstock was over set too much to start with in order to ensure lathe turned faces concave rather than convex?
Robert Hawtin Hi Robert,
I think the lathe had not been used for anything long for some time. It had probably been moved several times since the last time it was adjusted. I do not believe it was an intentional offset. Thanks for the comment.
Cheers,
Tom
Hi Tom, very nice presentation. You aligned your the lathe on the vertical plane, how about the horizontal plane?
I had to do just the same you did years back and I thought I am nuts to take the head stuck off the bed. Also I found under the head stock brass shims. I assume they are there for the feature scraping, to lower the head stock or just correct the angle against the bed.
Thank you shearing all your insides.
Radu
Hi Radu,
I don't even want to thing about the horizontal plane. That is going back a ways to access any adjustments. Thanks for the comment.
Cheers,
Tom
Hey Tom, thanks for the videos! just curious...i have a bench size lathe and i don't have any jacking screws, could i chuck a nice chrome piece of round up, indicate it in, and then do a sweeping indicator reading off the compound rest to measure taper? Hopefully you know what i mean.. Thanks!
Thanks for the video to go with ice cream on this Sunday evening! You are right about twist and flexing bolt tensions and jack screw pressures and all the fun stuff that goes with adjusting the alignment. I love to talking to mechanics about alignments only being math problems, even though I have lived the experience of the for mentioned! I work alignments as a ratio, in addition to the two indicators you used, add two more at the jacking points. formula; using the length between forward and rear jack screws or jack screw span divided by double spindle indicator span equals ratio. Ratio times the movement needed on your choice of jack screws. When I tear down my carriage to make and install a new nut and screw I may take a look at my spindle alignment too! That was a great subject matter! Tom
Cheers, Keith ;{)-----
Hey Keith,
Thanks for the comment. The jacking arrangement on my lathe is lets just say jacked up. There is no good pivot point to help with the process. I ended up moving it away from the jack points so it could pivot enough to bring it into alignment. I tightened the snot out of the big holdown bolts in the hope I won't have to do it in the near future. The ratio approach makes a lot of sense. Looks like I need to buy a couple more indicator bases. Yipppee more tools.
All the best.
Tom
Hey Bill,
Remember the pipe I use for the rod bender? Well that's the snot part of this operation. Guessing here at around 200 lb/ft with that arm. One oxpower was used which is equal to 5252 lb/ft min.
Cheers,
Tom
Very informative series, Tom.
Thanks.
Hi Joseph,
Thanks for the comment and compliment.
Cheers,
Tom
Tom you ended up moving the head stock itself to correct the taper in this video. If the headstock wasn't level with the ways would it have resulted in the same issue? Is there a similar adjustment on a lathes' headstock for that alignment or is that in the ways themselves?
Hi Hank,
There is no adjustment for up down just side to side. I guess its easy to make the spindle bore parallel to the base of the headstock casting.
Cheers,
Tom
Another great video. I can appreciate the accuracy you need.
Hi Tom, it's a bit late for my comment , i started watching all your videos from beginning. When I was in school 20 years ago they says that the overhang in the chuck can not exceed 3 times the diameter of the part, or you have to use the tail stock to support it, that's to prevent a small flex and vibrations in the part. Can it be that 0.001" difference comes from this vibration? Is this a true statement? Thanks. Bobby uk
Hi Bobby,
For regular turning you are correct. This is a special case where we want the most separation between the turned bosses as possible. If you watched the video I just barely took a cut on them. The bosses make it so you do not have to cut much material at all. The large diameter is stiff enough so the push of the tool is not a factor. Thanks for the comment.
Cheers,
Tom
In accordance with South Bend, Clausing and Cincinnati Lathes, for this to be accurate you MUST turn the shaft between centers because this gives you a more accurate measurement of the twist/off-level of the lathe. Where can I find any writeup about using a chuck and no tailstock?
+Gilberto Diaz Castro Hi Gilberto,
Better check your references. How do you know any taper is not caused by the tailstock being mis-aligned? Most tailstocks read low when swept with a test indicator. Which is hard enough because of sag of the indicator and support arm. Thanks for the comment.
Cheers,
Tom
Seems like we both are on the right track once we look at the different objectives. The method you explained endures the ways and the spindle are aligned, the method explained be South Bend and the others verifies that the tailstock is aligned to the ways... I gather the head alignment should be done first since it requires leveling the bed, then all is left is to verify the tailstock alignment... Now to see how my TrayTop is doing... Thanks.
Hi Tom,
I wish that when I align my lathe it will be as easy as when you did yours, fall asleep in the first 15 seconds and then when I wake up 42 minutes later and it's done...! Yes...
Well done video, everything to complete successfully the task is there.
All I have is a garage Cat called ''Gros-Tata'' (It's French) He rushes out when I show up and scratch at the door when I leave, he doesn't like the noise of the machines, he FREAK'S out.
Cheers,
Pierre
Hi Pierre,
Thanks for the comment. My magic wand wasn't working when I did this job. Had to do it the old fashioned way.
Cheers,
Tom
This is, by far, the most useful bit of instruction I've seen about setting up a lathe. On behalf of my old Logan, thank you!
Forgive the silly noob question, but why cut a chamfer in the test bar? Does it help keep the feed-in more accurate on the first cut, or is it just 'good practice?'
+Hessian Deiter Hi Hessian,
No particular reason for the chamfer other than attention to detail. It does provide some lead in for the tool but its negligible. Thanks for the comment.
Cheers,
Tom
I've seen the same thing done between centers but I see now that method would only align the tailstock. Is that correct?
Hi Bill,
The sequence is Level, Twist removal, Headstock alignment, then finally tailstock alignment. Tailstocks have a nasty habit of not being where you think they are. This is why I prefer to keep it out of fundamental alignment of the machine.
Cheers,
Tom
This was very educational, it makes you wonder how much work goes into making machine tools and making them accurate and consistent.
I don't fully understand how you knew that you got all of the twist out of the bed and needed to adjust the headstock?
How long did the whole process take?
Hi Tyler,
The whole thing took maybe six hours. It was over the course of a week. The measurements show basically no change going from level to not level and loaded at different points. What I mean is the leveling feet had no real effect on the cutting conditions.
Cheers,
Tom
Instead of doing the test cuts could you chuck up some precision bar and with a dial indicator on the tool holder check for taper both up/down front/back ?
Hi Lasse,
There are some methods with very straight and accurate test bars. This requires more careful setup than the test cuts. What we care about is parallelism of the tool to the axis of rotation. If you don't rotate then it introduces other uncertainties to the measuring.
cheers,
Tom
It isn’t clear how you’re separating bed twist from headstock misalignment. You didn’t seem to demonstrate how you can tell one from the other.
Awsome video. I have a question, what if you were concerned that your headstock was out? Could you check it in the same way with a test bar? Thanks
Hi Aw,
If you had a known test bar and could hold it straight then it would work. The test cutting is by far the easiest and most foolproof method to check for lathe mis-alignments. After all we ultimately care how a machine cuts. How do you qualify a test bar in your shop? You need to check for straightness and cylindricity to understand where any measuring errors come from. You need to make sure you take your measurements along the centerline of the bar as well. Not always an easy thing to do.
Cheers,
Tom
oxtoolco We have a pretty decent inspection room here in our shop. I guess what I meant to ask is if your machine is cutting a taper how can you tell if it's out of level or if the head stock is out of square. BTW, I heard you mention Hayward in one of your videos. I work in Fairfield for the Ball Corporation :-)
Thanks again.
Sonny
Hi Sonny,
I would start by precision leveling the machine to see if you can eliminate your taper problem. If you see little to no effect much like I did in the video then take a look at headstock alignment. The point it to be careful to not introduce another source of error from the wrong place.
Cheers,
Tom
Re 35:30 Truing up side to side. Why not set the tail stock rigidly in place to hold that end fixed? Then your head stock adjustments will only affect the chuck end.
Hi Ryan,
You can't have the tailstock influence the test cutting. It has its own set of alignment errors that confuse the readings. Thanks for the comment.
Cheers,
Tom
So regardless how trued up the tail stock is, even if it is absolute perfect, you don't know for sure that it isn't throwing a variable into the works.
That makes sense. Also demonstrates your long term experience with lathes and these issues.
In watching these videos it's absolutely unreal how many tricks, tweaks and little nuances experts like you know. Reminds me of when I was learning motor winding and my buddy, a winder of 40 years experience, told me, "It takes about 5 years until you are smart enough just to not ask stupid questions."
hi I like your videos and been very helpful.
I had a query, when I am turning a shaft, both end of Shafts are quiet OK, but the middle portion of shaft gets tapered.
can u pls guide me.
Hi Tom, Wow, not boring at all, highly informative, I would have had no idea what would be involved in that process, I can easily see how tedious and frustrating this could be. I think I would be afraid to do such a test on any of my lathes for fear of having to slog thru such a procedure, and in my case, excavating would be involved as well.
Excellent informative video .... Mike
Hey Michael,
You might save some work tunneling in from the outside. Come up right under the lathe to adjust the levelers. If it aint broke don't fix it is a good maxim here.
Cheers,
Tom
Just thinking here about a method of confirming if the load on a pair of feet is equal and I've been thinking about this since I heard the ring when tapping on one of the feet. Long sentence but I wonder if the change in the ring is relative to frequency, load on foot, and if that change in frequency can be measured with an app. There's more to this but there must a long term stability benefit in carefully balancing the load. Thanks for the interesting video.
Would a much longer bar have made it easier to set up the machine. ?
Hi Colin,
Not really. What we need in the test bar is the ability to discriminate the difference in diameters to about the limit of our measuring ability. A longer bar gives us better resolution but at the expense of a much larger size as it needs to be unsupported by the tailstock.
Cheers,
Tom
Ok I understand the accuracy you're trying to achieve but for a backyard turning operation dose it really matter I mean what's the accuracy of the mating face?
Tom
I have a 4900 Clausing lathe. It "appears" that the headstock is pinned with a dowel to the ways. Have you seen this?
Again great info.
Jerry
+Jerry Halcomb Hi Jerry,
Not all lathes have adjustable headstocks. Be sure you understand your geometry problems before you suspect headstock misalignment. Be sure the machine is level and straight first. Thanks for the comment,
Cheers,
Tom
Yea your not twisting it much if any!
Years ago I battled with a fairly large hollow spindle lathe, 9 1/4 bore, that cut a taper and we were constantly messing with the tailstock to try and compensate
Finally figured out the headstock was off and it turned out all the bolts were loose
and the adjustment screws that moved the thing on the gear end that are supposed to lock against each other and then had jam nuts weren't even tight against the block........ Yea it takes a while but once I got it sorted it was a whole different
machine and a joy to use!!!
Hi Gent,
Even as long as this lathe is I only got a couple tenths. I can feel you on the big lathe. Compensating for a jacked machine is a royal pain in the neck that you rarely have the time to fix.
Cheers,
Tom
Hi Tom. Another great vid!
Was wondering.....Have you assumed your bedways are not worn in the vacinity of the chuck. I was thinking potentially the nearest way could be worn say .001 , in a saddle shape, which would set you off chasing your tail from the beginning as it would show maybe .0015 or more on the test diameter.
Hi Nick,
This test gets you as close as you can be with the machine you have. It does not cover the entire length of the machine. When we look at the overall length the tailstock comes into play and that is a can of worms all by itself. Thanks for the comment.
Cheers,
Tom
Great information Tom. Newbie question most likely, how sensitive is this process to the chuck installed - I imagine your lathe is now 'calibrated' if you will to the 6 jaw. I imagine if you have a 6 jaw you are only likely to switch it out with a 4 jaw where you are going to have to dial in over the length anyway, but if you say had a collet chuck how close do you think your taper results would be?
Hi Steve,
The workholding is not part of the test. We are measuring about the axis of rotation. Imagine if the test bar was running out .010. Once we cut it to a full cleanup that cylindrical surface is coaxial with the spindle rotation. I would not expect any difference in taper switching work holding gear.
Cheers,
Tom
Great video,you have inspired me to set my lathe properly.
Hi Paul,
Thanks for the comment. Let me know how you make out.
Cheers,
Tom
Hello Tom
Great video. These problems can be a real pain to rectify. The spindle bearings can have a lot of influence on tapers as well. They can lift to different heights depending on RPM. Even belt tension and cleanliness on units without headstock gearboxes (CNC mostly) will affect taper in my experience. A question, my main concern was when moving the headstock so much did it affect the flatness when facing? It doesnt take much to make a big change there.
Cheers
Darren Wright Hi Darren,
Yes it did. It improved it as you might expect. Facing flatness is actually difficult to check on the machine. Thanks for the comment.
Cheers,
Tom
Hi Tom, Are you going to do another test bar between centres to align the tailstock?
cheers
Roy.
Hi Roy,
I will probably just sweep it with an indicator. I don't think I will do any test bars for the tailstock.
Cheers,
Tom
could you have used a large face plate or the outer edges of the face of the chuck to indicate the adjustment?
Hey Rick,
You would not be comparing the carriage travel to the spindle axis with the faceplate method. We are trying to eliminate errors in parallelism between the spindle and carriage travel (ways). Thanks for the comment and suggestion.
Cheers,
Tom
wouldn't perpendicular face plate to ways make spidle axis parallel to ways when adjusting head stock?
Like traming vert mill, with 2 dial indicaters.
Rick Brandt Hi Rick,
How do you assure the faceplate is flat? You can't use the machine to inspect it. If you face it then measure it could be some conic shape. The beauty of turning a test shaft is it exposes misalignment or twist directly and in an easily measurable way.
Best,
Tom
Awesome job!!! Thanks for sharing that with us.
Actually, you should loosen the jacking screws after you tighten the headstock bolts. You want the headstock to move if you ever have a crash. If things can move, they are less likely to break.
Hi Wes,
If you loosen the jacking screws the headstock would shift. Its kind of a push pull arrangement. Its not designed as a safety measure for crashes. Thanks for the comment.
Cheers,
Tom
Yes, the push/pull screws are the ones I'm talking about. The headstock should have a center spud or hub that allows it to rotate in what would be the Y axis. There will be a pair of push/pull screws that let you adjust the rotation. Mazak and Mori call them "knock bolts". Other lathes have no spud and use 2 pairs of knock screws. I recommend that you leave them loose. The headstock bolts will hold the headstock in alignment. Like I said before, you want the headstock to move in the event of a crash. Every manual I have seen recommends leaving them loose after the alignment is achieved.
Some lathes have jam screws that you can used to raise each corner to align the spindle in the vertical plane. Obviously you can't leave those loose. That's not a great design though since the bearing area of the jam screws is so small.
Hey Wes,
This machine does not have the center pivot like some CNC lathes do. Not quite the same system.
Best,
Tom
It doesn't matter. Some CNC lathes have no spud and use two sets of jacking bolts.
I guess you're committed. It's your machine...
You also need to realign the tailstock after moving the headstock.
Hi Wes,
Its not that I don't believe what your saying is correct for some machines. The YAM manual clearly says "After obtaining the proper alignment, tighten the fixing bolts, then tighten the six hold down bolts" After screwing around with it for a few hours I'm not touching any of them. I'l risk any potential consequences from a crash. Thanks for the comment.
Cheers,
Tom
I have levelled my lathe , following the video and it cuts great. Now, the coolant flows the wrong end of the bed, away from the drain/pickup area, towards the headstock.Any ideas?
Hi Sky,
Well is sounds like the position you found is not particularly level. I would suggest that you can find another position that the machine cuts well were your coolant will drain properly. The goal is to be as close to level as possible with the machine cutting properly and bearing on all the support points. Thanks for the comment.
Cheers,
Tom
Silly question as I didn't see anyone ask or mention it in the first 30 or so comments, could some of the taper you were chasing be caused by worn bed ways? We have several old(er) machines where I work that will cut taper up by the chuck where most of the work has been done, and cut straight further down the ways... This with exception of the lathe that has pretty much only turned shafting, which has fairly consistent wear for the length of the bed.
Hi Ice,
This lathe has hardened bedways which appear to be in good shape. You would have to do a much longer sample to expose and diagnose that kind of a problem. This was pretty clear case that the headstock was out of alignment.
Cheers,
Tom
Thanks Tom for the Great Videos. I have a random question? Living in earthquake country do you ever have to go back and test and level after a shake?
Only the big ones......
Cheers,
Tom
really interesting tom, wouldnt it be better to measure for error over a greater distance like 1m?
Hi Jon,
You are right it would be better. The bar has to be self supporting without a center in the free end. So to do a 1m bar it would need to be 200 or 300 mm in diameter.
Cheers,
Tom
ok i see didnt mean to sound like i know better
jon white Hi Jon,
I didn't take it that way at all. The longer the bar the better the resolution.
All the best,
Tom
"Tools are good". (Mr Wizard - 2014). True dat!
Always like Ernie's cameos.
Best. Chuck.
Thank you. This video really helped me out. I used a tube instead of round bar was the only difference. The headstock was out on mine about .006 was able to get it to .0005. Not perfect but a lot closer. Thanks again
Hey Chris,
Glad the video helped you out. Thanks for the comment.
Cheers,
Tom
As you may know Im back in my machine shop after watching you and fenner' I bought a new 8 in starrett level to check my enco 13 = 40 lathe that i never leveled and it was out so i got it pretty plumb and level and then did the two ring cut test and i was happy to see it was at most two tenths of a thou out in ten inches.
Hi Jim,
Good deal. Ten inches out. What size bar did you use? Thanks for sharing.
Cheers,
Tom
My bar is one and three quarters bye twelve long.
hey tom , am doing my under graduation in mechanical engineering
and i kind of like machine shop very much because you can show your way of creativity and art, the engineer's way....And I kind of learn a lot from your videos ,those little tricks help me a lot in my college shop ..... so am much obliged for that.....
(thank you) x (n) - for the upcoming videos and the past videos
and I saw in one of your videos , you have a marking up the viewer in the world map kind of stuff ....so I would like to see If any one is from INDIA if not I would like to be the first one ....
Hi Msshyam,
Thanks for the nice comment. We do have another viewer in India I think in Bombay. He has a shop there I believe. Best of luck with your engineering career and be sure to learn as much about how things actually get built in the shop. It will pay you back a thousand times. I put you on the list for a pin when I get back to that.
Cheers,
Tom
I am writing from Oz. I am familiar with the breed, and have had close relationships with some. I was unaware that they had made inroads into CA. It is good to see.
Richard.
Tom, I enjoyed the video. I may do this same test on my South Bend 10" heavy. The headstock is not adjustable but the bed has some leveling feet/screw gizmo on the far right end.
Eric
Hey Eric,
Let us know how it works out.
Cheers,
Tom