James, I have been watching your channel since your tool post grinder series so it's been a while. I have to say you have had an amazing improvement in your filming, editing, and content delivery over the years. Your videos are so polished and your content is top notch.
Hi James as a former machine tool maintenance guy , nice work! as others have suggested perhaps a know good quaility 5c collet is the next step. A 3/4" hardinge collet from their online store is $75 lyndex is also high quality and about half that. at the end of the day you do get what you pay for. the ultimate test for a spindle (runout and alignment) is a solid test bar . there is obviously a limit to how good an old collet closer and a low cost hobby lathe can be There is such a thing as " close enough"
One suggestion, since you corrected a considerable amount of runout by re-clocking the backing plate I'd suggest putting some punch marks on the two pieces for future reference. You don't won't to put it back together wrong way round again in the future.
You could mount just the back portion of the chuck, and test the rear collet support area for concentricity. I would really look over that split in the chuck for anything out of the ordinary. Some 300 pound gorilla might have tightened the bolts enough to lift those areas. I have seen that on surface grinding jobs that have threaded holes.
That looks like a great candidate for a milled slot and a spanner wrench for install and removal! I’m inspired but your willingness to make all your tool’s perfect.
I barely took a breath the whole time but you appear to have taken approximately the same approach and I'm glad it worked! It's kinda crazy that you can do better in your shop than the result of factory plus years of wear. Pretty empowering even if terrifying
Dang, James. The more you improve this chuck the more I wish I'd bought it from Dale when I had the chance, and done a D1-3 to D1-4 conversion to match my small lathe.
Hardinge (Elmira, NY) guarantees their collets to .0002 TIR. They're a little pricy but it might be worth getting one and seeing if it would be worth investing in them instead of trying something else. Harding collets are one piece. Most imports are two. That may be the difference.
Only the Hardinge "Special Accuracy" are 0.0002" TIR (about $85 each!). Hardinge Standard 5C collets are 0.001" TIR! So if he is getting under 1 thou runout now, it is definitely the collet doing that being it is an import collet.
Guessing from the measurements he's getting over the pins I would say the collets are not at issue in this situation I'm assuming the collets must have come with this Chuck meaning they're old meaning they're high quality unlike the China trash we are being force-fed. Even quality brands have their junk made in China.
Nice fault finding and rectification James. Having speculated on the adapter mating faces being affected by torque previously, I am pleased to know I was wrong. Thanks for the journey.
I've never attempted anything like this. I've also never done a lick of machining in my life unless you count sanding a wood block in a drill. I'm just here because I find this entertaining.
21:47 boy, that was satisfying, that needle was nailed in place, soooo good to see it not moving. I saw somewhere that if you mach two machined surfaces to each other, like that collet is matched like a dream to that chuck, it will be a bag of cats in any another chuck.
If you were confident in your headstock alignment, I wonder if you could improve the result with an aluminium lap on a mandrel in the tool holder. The lap could be accurately made between centres, which could also be used once the mandrel is transferred to the tool holder to ensure accurate alignment. Once positioned and the cross slide locked down, move the saddle out of the way, install the collet chuck, apply some lapping compound, and you're off! The only complex task would be the transfer, but I think you could measure any misalignment with a test indicator or two to show deflection when you clamp it down.
Good work, it's nice to get things that are not right back to right. And indeed, it's lovely when the tooling throws the work in your face. Single point grinding eh, why not. I too would live with your result.
Had the same exact problem with the same chuck. Sold it, priced accordingly, to somone with the patience to bring it back to life. Ended up just going with a collet handwheel and spindle bore adapter. Great video!
youre regrind looks promising, I believe you are on the correct track as far as the next step, first i would suspect the collet, after that the back journal. you will find with the back journal you can lap it to deburr it, there is usually quite a bit of damage back there so the most important thing is to get the high spots down. dont forget, the .001 your seeing at 1/2" off the face would be 4x that on the back journal. But i would suspect the collet above all else
Great analysis and result here. One thing that I think could have been interesting would be to measure the runout using a few different sizes of gauge pins. In theory, the larger gauge pin (just one or two thou larger I would think) should run truer since it is forcing the collet to contact the taper further out near the end where you've got the grind perfect. Whereas a smaller gauge pin would probably show a much worse runout.
Awesome video on troubleshooting a problem and diminishing returns, this should be a required video for everyone, as the concepts can be applied to any field.
Good job. My first dovetail was not too long ago when I bought an older but higher end lathe than I had at the time and it was missing the compound and the cross slide lead screw. $200+ of cast iron and a lot of patients.. Thanks for the video.
spin up a solid bar between centers that otherwise is identical to a collet but without splits that wedge it in the chuck. then since it wont collapse and shrink into the chuck any error in the chuck mounting surfaces will be directly visible in solid collet once its pulled up/in and mounted. the solid collet will act like a gauge pin or other such things, but be instead of parallel or triangle shaped the end of it mounts as a 5c collet.
Great job with the pencil grinder. I have been using them in a V block for years, mostly to true the face of diamond and borazon wheels. A shop i worked for used a pencil grinder on a cnc grinder for a very high speed head. Collet on pencil grinder not running true was the biggest problem.
We had tons of issues with our R8 spindle and collets for our Grizzly cnc mill conversion. You have to keep going! We where never able to eliminate .001" run out. We did everything you did and more. And just never figured it out! Try lapping the collets. We tried that with no improvement. Buy a precision collet. We did that with no improvement. Try to re grind the collet. We tried that with no improvement. It was just impossible to find the error. in the end we had to try to cancel out the run out by hand for each tool. We also found the bearings in the head had some runout as well and replaced them with no improvement. So you have to keep going. Find a way to get down to .0001" run out for all of us and show us how you did it.
You're likely at the runout limit of an old 5C collet. Even a brand new Hardinge 5c collet in a master spindle will be .0002-.0003" runout. I'd call .0007" with an old collet pretty dang good for a reground spindle. Well done.
Several comments - nice effort. I would suggest getting a reference 5C collet. Hardinge makes special super accuracy collets, they have 4 slots and the best TIR they offer. Not cheap and often used on tool grinders (I have a set for a Cuttermaster). Then a straight and round pin is needed to check TIR at the nose and as far out as the pin length permits. I've found that drill rod and drill blanks are neither round or straight enough when in the tenths world. Dowel pins I've bought from McM are straight, round, and are relatively cheap. (it kinda makes sense - bent dowel pins don't work). A set of these then can be used to measure 5C and R8 collets. A set by 1/8" steps to 3/4" won't break the bank, I bought the longest offered. Subsequently, I threw out a lot of R8 collets and some 5C. An R8 MSC brand set won, but I don't have any of the best brand name R8's. Then with your surface grinder you can tune up v-blocks to match and have the V bottom parallel with a dowel pin. It's fun to do that.
I’m not sure if someone else mentioned this or not… When I installed a collet chuck like this for a shop I used to work at, the chuck was adjustable like a 4-jaw. Brand knew the runout was .005”. I adjusted it to .0002”. It took a bit of time. You have to loosen the bolts in front and adjust it in like a 4-jaw and tighten them.
It's worth noting here that gage pins are not always perfectly round. Some pin classes are intentionally tri-lobed. I would suggest that you get a dowel pin and test the runout to see if you get the same results. I do think you taught a very important lesson with this video. Always take notes when you are disassembling something so that you can put it back together in the exact same way. It's especially easy to do these days since everybody has a smart phone with a camera in their pocket.
The remaining error close to the chuck has to be the collet/material but farther out is the register inside. Try a long indicator probe to measure that runout deep inside before doing anything. Nice to see inside one of those. We have one but I don't particularly like it. I like the back of the headstock locking lever type. But the very best is the Royal air powered collet closer. I like those because I like to change parts on the fly without stopping the machine.
Others have mentioned the need for a known-good collet, now that you are down in the range of where the import collet errors may be dominant. If the taper measures concentrically, then there's nothing else to do with the chuck for now. Of particular concern is that the collets are only contacting the chuck at their split points. That tells me that the collets are slightly oval in a way that tightening is not taking up.
James, I would have liked to see you use your shop made tool post grinder, with a Norton 46 grit amumiun oxide wheel. have not had much luck using pencil grinders for prescion work, the bearings are too spongy. The job came out really good in the end, due to your skill set. 👍
@@ADBBuild I went back and viewed his build video. You are right, as he as no provision to use smaller mounted stones. It looks like he cold adapt an er-16 collet holder to the spindle. Maybe he will look into that project in the future. 👍
I came across this phenomena many years ago with the run out in a 3 jaw chuck on a dividing head and the guy trying to get a mandrel to run true by resorting to hitting the back end of the chuck jaw with a copper punch in the vain attempt to get it to move a couple of thou..........without asking permission I re-machined the backplate register to give it a .005" clear and the rest is simple to get the part to run true.......this trick will work for any 3 jaw chuck when you just must have the part it's holding to run true.
great job, get a new premium collet and test, check the back seating surface , have it built up with spray weld or use moglice epoxy or press a sleeve in and regrind as this chuck is no longer in a production environment im sure you you can get better as spindle bearings show very little runout
I think you have gone as far as a 5C will let you, given the straight diameter at the threaded end of the collet, and there being no way of correcting the adapter diameter to bring it concentric. Good job on the ID grinding, came out nice.
I made the mistake of buying a cheap import 5C collet holder, thinking how bad could it be. To cut a long story short, after making a bump-tru back plate and a whole of other fiddling, I drilled the chuck body to intersect with the inner alignment surface, inserted some hard bronze pieces and bored it true. For a while I got virtually zero at the collet face and at 150mm from it too, but as I say only for a while and only with one of my genuine collets, the import ones can be "variable".
I concur, to quote Adam Savage "You're just chasing Zero's", after a bit of this. The results invert with time to progress." {I probably mangled that in my memory, after a time chasing zeroes, you don't see much progress on a LOT {in cost too}, mostly it's time. I have confidence in you gettin' it all to nothingness. 😁
You could go the swiss way, and get a morse taper reduction sleeve with a set of w12 or W20 collets to fit directly into the spindle and toss the 5c collet chuck...
Vary nice job! I would call that good . I’ve been a machinist all my life and I build pool cues for a living. I have ground many chucks and you can only go so far before you start backpedaling. 😢
Nice job on the chuck. As others have said a high quality collet would make a big difference in what you are seeing for run out. Also why don't you drill a hole in the outer dia. of the adapter to fit a .500 dia. bar to tighten and loosen the chuck on the spindle instead of the strap clamp?
Since the adapter plate doesn't need to be in a certain position I would have put it back on in a different position. That way when you finally part ways with that chuck, for whatever reason, it will really confuse whoever gets it after you.
If you wanted to get better life out of this, doing what you did, and then having the item hard chromed, and then mounting between centers and hard grinding a thin coat of the hard chrome with something like diamond wheels would give you a true surface, and on a material substrate that is extremely hard compared to the actual tool body. This would wear much slower than the tool steel body. This would also let you repair something even if it's worn out otherwise, you just grind the new plated surfaces. I do this kind of work daily, but not on tools.. excellent overview of dressing grinding and going through the errors and the glazing that happen during rotary grinding
Cant tell you how many times ive had my knuckes smashed into the ways when knocking a chuck loose with rubber mallet. You always try to be ready but somehow we never are.
I use to use a cutter grinder spindle to grind in tapers never did i ever get runout less than .002 with a import 5c collet i purchased a set of hardinge high precision 5c collets i thinkyou got it better than you should have with import collets how many times are you going to need it any better but i understand why you do because but is it worth 2500 dollars for a set of hardened and ground precision collets i think you got a great collet chuck now i would bet the bearings in the spindle of the lathe will not hold 0008 for long unless you have already replaced them too you do great work always a pleasure to watch your videos from a 50 year retired machinist
I have tried to drop a part on a finger. It only fell 10-20mm, and the part was not long and only about 50mm in diameter, but on the underside of my finger was the sled on the lathe, which didn't didn't budge... could feel that for a week
Nice job. More work but for accurate common sizes possible to internally grind few collets in situ? Even more work.....but if lathe spindle bore big enough make a drawbar collet chuck? Could register in spindle bore and thread on outside to hold in place perhaps. Got drawbar collets mounted directly in spindle on 80+ year old leinen lathe and run perfect and zero overhang from spindle bearing so nice and rigid, much better than Crawford d1-6 collet chuck on other lather (but obv larger lathe so likely to be worse I guess)
Interesting. I’m curious what happened to your tool post grinder build and why you are not using it here? That tool post grinder looked like it turned out nice!
Now this is quality content! But, sir, please, oh please next time use tens indicstor, its helluva eyesore trying to look in to those 0-3 thou idscrepancies..
Imports... I bought a Morse taper #3 to #2 adapter from an importer were the inside was visibly off center producing ridiculous runout. I got it exchanged and the new one was even worse! Must have been a bad batch from the factory. The supplier gave me a refund without question. Anyway, I also suggest you borrow or buy a quality collet for your testing.
collets were riding on split points. Y might want to lighten those points on your cheap collets. So that the load point is divided more evenly through collet chuck. Your collets just going to grind and scrape your chuck again.
I would fabricate a solid piece of the collet and the other end to fit the tailstock. Center it. Lather it with grinding compound. Run the lathe on maximum speed and sliding the solid collet in. You will get it down to under a tenth 🎉 something like engine head valve grinding to set the engine valve in cars 👍🏼
The chuck needs an adapter backplate anyway, so how about a new backplate which is is slightly off center (by as much as the the back surface is on the current one), so the error there is canceled out. the taper in the front would have to be reground this way, but the collet would sit perfectly straight in the chuck. alternatively a new backplate, but the back surface is machined on the chuck (ie. the regrinding you mentioned, but as it would only be on a new back plate, it is on a disposable part and even on a failure a comparison with the current back plate should give better measurements how it should have been (to machine a third one with that off center error measured before). and if it goes well....
Even Hardinge's branded collets are TIR 0.001" ($51 each)... so those cheap import collets are never going to be better than 0.0005" at the best. If you are at or under 0.001" of runout that's most likely the collet at this point.
Like always great video. But in another hand I was wondering why you dont make hole in that adapter for removing it(as you can just put inside pin/screwdriver and rotate it), so you would not need to use strap clamp. Or that would mess balance of adapter too much?
Биения в районе 0.01 дюйма (0.23 мм) можно увидеть невооружённым взглядом. Для этого не нужен индикатор. Биения такого порядка означают, что у вас нет станка, а есть просто крутящаеся нечто.