My Tailstock is worn out!!!

[retailer]

I had the exact same problem with an elderly (over 100 yrs) lathe and as Wizard said try hardchroming, I took the complete tailstock to a hardchrome and grinding company, result was a perfect fit, they do that sort of thing all the time.

 

[Wizard69]

I had the exact same problem with an elderly (over 100 yrs) lathe and as Wizard said try hardchroming, I took the complete tailstock to a hardchrome and grinding company, result was a perfect fit, they do that sort of thing all the time.

The hardest thing about hard chroming machine parts is finding a shop that does that sort of work.

Also almost 40 some odd years ago I worked a bit with a guy that knew machine tool building inside out including rebuilding of machine tools. If I wasn't so young back then, with the mind on other things, I could have learned a lot. In any event hard chrome was used often to recondition finely fitted parts. This guy did wonders with hydraulic pistons hand fitted to their cylinder bores as used on big OD grinders.

 

[purpleknif]

Had the same prob on my 7 x 10. Is the quill rotating at all? Mine got fixed with a new key.

 

[Brian Rupnow]

Had the same prob on my 7 x 10. Is the quill rotating at all? Mine got fixed with a new key.

No, the quill doesn't rotate. I'm really not sure exactly whats up with it. As far as hard chroming and grinding the quill, a new quill is only $45. I doubt very much that you would get it hard chromed and ground for that price. If the bore in the tailstock is worn out, that's where the big ouch is.--A new tailstock barrel is close to $200.

 

[MCRIPPPer]

thats why i made a tailstock gasket if you can call it that. look im my x2mill and mini lathe thread for images.

it does not fully seal the tailstock because the quill has a slot milled in it, but it wipes the shop dust (usually abrasive!) off. and keeps most of the oil from seeping out.

 

[user 284]

My feathers weren't ruffled. I am fully aware that there are books available from "experts" available on every subjects from sex to skydiving. I am capable of seeing what appears to be a problem. I'm not always sure just what to do about the problem, but a good start is to discuss it with other people who use the same equipment and see if they consider it a problem or not. Thank you all for your helpful contributions.---Brian

Well to be 100% honest you would need to do some very accurate measurements on your tailstock using a very good and I think 100% trustworthy 10ths reading dial test indicator. But I warn anyone who hasn't ever used an indicator of this type before in a horizontal setup that you really won't believe just how much a very light weight DTI can flex even a .250" diameter shaft just under gravity conditions. I used up more than a few hours due to this effect the very first time I checked a tailstock and trying to adjust a tailstocks height to a true zero to the headtocks C/L.

Due to the way a lathe cuts, the vertical C/L height on it's tail stock has much less effect than it's alignment for side to side. And most top quality lathes come right from the factory with the tail stocks ways purposely ground and set so the tailstocks bore is high, usually from a few thou to over .010 high. They do this so the tailstock slowly wears into alignment and not out of alignment. With a 2 piece tailstock I'm not all that sure I agree with that thinking as I'd rather have the tailstock correct to begin with and then shim to compensate for any wear over it's lifespan. As I said, the taper effect on parts turned between centers is very little. Drilling given how imprecise that normally is also has very little effect with a tailstock being out of alignment vertically. If your using your tailstock to do high precison reaming with either gunsmithing chambering reamers or the standard machine reamers, then I happen to think your lathes vertical alignment is critical if your wanting true on size and straight reamed holes. I had a Seig C-6 that had the tails stock's barrel pointing uphill .009 in just over 2". It was a really excellent lathe for instantly breaking the tips off of center drills.:wall: But if your going to go to the effort to tune the lathes tail stock so it's really aligned with the head stock? Then it also requires a very good quality drill chuck and arbour. Dead on tail stock alignment with a drill chuck that gives you .010 or worse for run out is a bit of a wasted effort.

But my whole point is you just can't blindly trust any machine tool to be 100% correct no matter who makes or made it. Mistakes and misalignment's can and does happen with the very best manufacters in the world, and on brand new totally unworn machines. Yes something like that would be more than rare, but it can and has happened. If you don't check a machine tools critical alignments then you really have no idea of exactly what you do have. Any good machine shop or parts manufacter will go to great lengths to properly align, test, re-align and re-test any new and very heavily built commercial machine tool they purchase to wring the absolute best accuracy out of it no matter how much they spent on it. Yet we hobbiest's somehow expect to just bolt a probably quite cheap (compared to industry) machine tool down to whatever uneven bench surface that's handy and turn out parts to at least .001 accuracy with an unchecked or even tuned machine tool? I've spent far more time learning the little I do know about this than I'd like to admit. I certainly don't think it was at all a wasted effort. But it's sure made me far more critical of the machine tools I'm buying, and I don't hesitate to run a full test and readjustment at any time. I've got an Emco Compact 5 lathe that I've adjusted to turn within .0002 taper in 12". Due to my stick built shop floor structure I'm damn lucky if the adjustments lasts 2 hours. But it proves it can be done. I've also learned a great deal about machine tools I've bought I really wish I didn't know to again be 100% honest.

And in no way do I mean this to sound arrogant or that I'm somehow a know it all, but again and unless you've read that Machine Tool Reconditioning book, if your a hobbiest? Then it's most likely impossible for anyone to fully understand just how critical it is to test any machine tool. It really is a very dry and very boreing book to read. But.........it will 100% change your ideas about what you think you know. It certainly did for me. Used ones sell on Ebay for a lot less than the $100 new price. To be honest, it should be required reading even though the majority of the book deals with grinding and scraping a machine tool back into alignment. At the bare minimum it should change your ideas even about machine tool lubrication and cleanliness. That alone has more than paid for mine.

Pete

 

[goldstar31]

I'm agreeing wholeheartedly with Pete! Sadly, I have to ruffle a few more feathers and remind you that you are - or should be replicating full size practice in making engines. You have a tailstock which is out. Looking at it- from across an ocean, is no more than a round bar, a hole in something-- and a sloppy fit.
If that worn hole was an engine cylinder- what would you do? You'd rebore or re-sleeve it.
If that was an old motor cycle or gas engine cylinder, you would find that an old book would contain a sketch of the cylinder being - in line bored. If you wanted to retain the piston -you would re-sleeve but if you didn't and could swop pistons, you would simply re-bore and hone.

I'm ruffling your feathers but- you are doing this. All that you are short of is a dummy tailstock and ad an inline boring bar. Maybe the dummy tailstock is just fixed steady and maybe the boring bar is a bit of round with a bit of hss tool ground up and stuck in it.

 

[Hopper]

You say the quill is soft mild steel. You could probably knurl it to increase the diameter then turn it back down to the required size. Rough, yes. But effective in a pinch.
But you would need another tail stock to turn the quill between centres on. I would buy the new quill and carry on.
Alternatively you could turn up an oversized quill out of some decent steel - bit of old truck axle etc could do it) and fit that. It's been done many a time before on older lathes.

 

[goldstar31]

(and you would need another tail stock to turn the quill between centres on.

Not so- you can effectively use a fixed steady and always remember that an in line boring bar between centres( or chuck and steady) will bore perfectly parallel. It may, if care is not taken, to check, bore the wrong diameter but parallel it will be.

Take your pick. Start with Archimedes, then George Thomas and Prof Chaddock-- but there are things like Buma boring bars.

I did up a rather nice 997cc old Mini Cooper engine to plus 60 thous.
The engine was £10 and looked as if it had run on creosote. Twelve inches to the foot Mini Cooper- not the toy one that grandson borrows from Grandpa:hDe:

 

[Swifty]

I'm a bit lost with this inline boring set up, I understand inline boring completely, but cannot see how the tailstock can be set up in such a way as to have the quill hole in perfect alignment with the slide way, and of course to have the finished height of the quill hole in the correct place. I believe that this would be too difficult to set up for the average machinist.

By necessity, the tailstock would have to be mounted on the saddle, and of course it would have to be lying over on one side, making it difficult, I'm not saying impossible, to get the correct quill hole height.

Paul.

 

[goldstar31]

This follows a classic set up using the centres or centre and fixed steady by inter positioning the tailstock mounted on the saddle. The boring bar goes through the tailstock.

This isn't quite out of the ability of the average machinist. You will recall that Dennis Chaddock did something very similar when the Quorn castings are bored 'precisely' 1.000" and 1.003" and exactly parallel to one another as bed bars. Then Chaddock puts the 1.250 pillar in a right angles in one casting and the pillar has a 1" thread to take another casting.

Done it twice.

You know most designs for home made dividing heads expect that you make your own- tailstock as well.

Perhaps some of us are having a bit of a blockage. I recall Sparey in the Amateurs Lathe showing one steady of wood. Cleeve described his steady out of solid steel and published designs for both the older Myford ML's and the ML7 series.

Me, I'm just a simple old soul- with NO mechanical training

 

[Swifty]

Perhaps this is the setup that is needed to bore the tailstock. Although the tailstock will have to be loose enough to be pushed by the saddle.

http://i288.photobucket.com/albums/ll168/TexasTurnado/PA100015.jpg

Paul.

 

[goldstar31]

The old fashioned way was to put a way in the boring the bar but mine are the ones which did the Quorns and have the tools set at- I think 40 degrees so that the tool bit can be advanced in controlled thous.

I apologise but I am too old and disabled for bothering with photos but those with access to old Model Engineers will find that Martin Cleeve made a small lathe from mild steel bar- and sintered bronze inserts. After all, there is not a lot of difference in information on making spindles- which are at the other end of the thing.

Regards

 

[martik777]

MTR ebook is free here:

http://www.scribd.com/doc/125118924/Edward-F-Connelly-Machine-Tool-Reconditioning-an-BookFi-org

You may have to upload something first

 

[user 284]

Unfortunately Norman and myself, and maybe it seems a few others might sound a bit arrogant since we've all read and have been semi machine tool educated by some of the classic I guess you could call them Model Engineer writers from the 1950's 60's and 70's.Or maybe the others from a profesional and well experienced education. I still say G.H.Thomas and Bill Benett? who edited Georges writings after his death produced the finest book avalilable for the home shop types with the Model Engineers Workshop Manual. If you've never read it? You really don't know what your missing.

Dragging or pushing the tailstock while your reboreing it to fit some type of bushing would at most make it incorrect for the lathes vertical C/L/ by what, a very few thou.? The lathes V way's would keep the tail stock dead true at least to the lathes bed while it was bored. Any rigid yet temporary method of setting up a dead center at the lathes correct vertical C/L to support that between centers boring bar will work. If you spend whatever time is required to get everything as perfect as possible, the tailstock can only be re bored a bit too low just from the slight clearances needed to allow it to slide while that reboreing is being done. You can then shim that to almost perfection. Certainly to far more precision than the lathes original brand new condition.

The very first metal cutting and / or threading lathe was built not by ordering parts from a OEM. And no it's not exactly an easy job to properly rebuild a tail stock so it's correct in all 3 dimenions, but I've sure got to agree with Norman. It's not impossible, or very much different from boring a cylinder either. That was an excellent anology.

Most of us just can't afford something like a fully rebuilt Hardinge HLV, we get to buy and use whatever we can barely afford most times. That does not mean you can't make large improvements in your equipment for both accuracy and ease of use. It's exactly the same idea as that 'sweat equity" everyone likes to use as the latest buzz word while restoreing or renovating a home. And while you certainly wouldn't have the built in rigidity as one of those very precise Hardinge lathes, it is within most peoples bugets if they want it bad enough to rebuild almost any lathe to far better accuracy levels than the original brand new lathe was capable of.

But only you can judge if it's worth it Brian, to go to the effort required, then the female Morse taper in your current tail stocks barrel really does need to be in like new condition to make that effort worth it. If it isn't? I'd order a new barrel, rebore and probably sleeve the old tail stocks bore with bronze bushings or a sleeve, and maybe add a few extra oil ports to slow the inevidable wear. Even going as far as getting a good engine rebuild shop to precision hone the bronze liner after it's pressed in shouldn't cost that much. $100-$200 tops for a fully rebuilt tailstock. A semi decent repaint on the lathe would probably cost that much.

George Thomas's book mentioned above has probably the very best between centers boring bar design I've seen so far.

Edit,
With a re read you mentioned $200 for a replacement tail stock barrel, a severe end user screwing if I'm any judge. You still need at least two bronze bushings, a short one at the front of your tail stock, and a long one that's a bit longer than the tail stocks travel at the rear. I've worked with hydraulic cylinders that were hard cromed and that's an excellent idea. The grinding after the hard cromeing could get quite expensive though.

Pete

 

[goldstar31]

Bill Bennett is- incidentally, Doctor William Bennett, a retired dental surgeon who graduated almost exactly 51 years ago-----------------------with my wife at Newcastle upon Tyne and was last of the Durhams. Amongst their tutors was a guy with a battered old Myford ML7 who made his own dental instruments - and played the organ---------------------at our wedding. It's not all fannying about - there is a real world out there.

Somewhere whilst Bill and the lovely Christine and 'Hoodie' were doing their cutting up dead bodies and watching a trolley bus run over a former air ace's leg, I was doing my thing -with a slide rule.

Oh, the leg needed a joiner as the guy lost the proper one in the war. He's still alive!

Apologies , but we were getting a bit serious!