What's new
What's new

Tailstock realignment questions

CountryBoy19

Stainless
Joined
Aug 14, 2012
Location
Bedford, IN
Going for a "90% rebuild" on my LeBlond and the tail-stock is in need of some truing up. The base droops about .009" from one end to the other. Putting an indicator on the quill gives me .018" droop (when adjusted for the length of the tailstock base).

I have no plans/interest (due to cost) of sending the quill out for chrome & grind along with reboring/honing the bore. If anything I would prefer to bore & sleeve the tailstock. But in all reality, I think the bore is acceptable to just leave it go. It's a bit on the loose side but not unworkable. Suggestions on more budget friendly fixes to the quill/bore?

The base definitely needs trued up. If I do all of the realignment of the quill by scraping the base then I have a lot of material to remove and it will actually cause the joint between the halves to be tipped back a bit. This isn't entirely bad because as the front wears down it will tip back down. But it won't be right. To get it "right" I will have to do something with the quill & bore.

My plan was to scrape true and glue a phenolic shim between the halves but I'm now wondering if that's an acceptable plan.

This rescrape/rebuild job will likely last this lathe the rest of it's lifetime, I'm not looking for overkill, just looking for functional fixes that aren't a major sin or travesty when it comes to rebuilding.
 
Although having the joint not parallel with the base might seem "goofy" I can't think of a reason why it would matter in ordinary use. If you're offsetting the tailstock a side-to-side droop would in theory drop the quill but barely enough to measure in any reasonable offset. From a practical standpoint (not a restoration for a finicky customer) get the base back in line with the quill, then either shim between the upper and lower or mill some more off the bottom and splice on some new cast iron.
 
Set the TS top on your surface plate with parallels under it and see if that is straight. You say your indicating the plates by sliding it under an indicator mounted on the cross slide? The droop in in the front or head-stock end? I would fix that if that's the issue because you will break off small center drills and if you drill long holes the will be egg shaped. If that's what we are talking about, set the TS bottom upside down and setting it on an original surface and mill the bottom parallel to it, then match fit it to the bed leaving the HS end thicker .001" so as it wears it will wear to the better. Then you need to do the spud test to figure out how low it is. Im getting tired of typing. Maybe one of the students can help out here and tell CountryBoy who is part of the family with 1 day of training..lol Rich
 
Set the TS top on your surface plate with parallels under it and see if that is straight. You say your indicating the plates by sliding it under an indicator mounted on the cross slide? The droop in in the front or head-stock end? I would fix that if that's the issue because you will break off small center drills and if you drill long holes the will be egg shaped. If that's what we are talking about, set the TS bottom upside down and setting it on an original surface and mill the bottom parallel to it, then match fit it to the bed leaving the HS end thicker .001" so as it wears it will wear to the better. Then you need to do the spud test to figure out how low it is. Im getting tired of typing. Maybe one of the students can help out here and tell CountryBoy who is part of the family with 1 day of training..lol Rich

I realize now that my terminology was confusing.

Putting the bottom half of the tailstock on the ways, at the tail end of the bed where it's relatively unworn, and using an indicator on the cross slide it leans to the back slightly, and leans toward the head-stock .009"

Putting the tailstock together, with the quill fully extended, and using an indicator set on the cross-slide the quill leans towards the headstock .006" per 4", or .018" per foot, and .001" per foot to the rear. The tailstock base is just under a foot long. So to completely true the quill up without reboring/reworking the quill itself, I need to take .018" off the right end of the tailstock base, but that will leave it leaning away from the head-stock .009" if I measure the original reference surface.

So is it better to have the quill running true and leave the base of the tailstock leaning away from the headstock a bit, or keep the top of the base parallel with the ways, and deal with the quill later?

Thanks for your help Rich, it's always appreciated!

BTW, I won't be able to do the spud test to determine how high I have to shim it until I get the headstock back together. I'm still waiting on another PM member to get that replacement gear made up.
 
remember you use unworn originals to bring the machine back to normal. The only reason I would bore and bush the TS bore or bore and chrome plate the quill is if the quill now is worn or loose in the TS bore. I would never re-bore the hole to fix a FK up on the ways. Use the unworn surfaces as a guide as 99.9% of the time the original machine was good. You should have the TS bottom plate parallel to the cross slide travel in and out or front of machine to back of the machine a max of .001" in 6". Other wise as TC I think was trying to tell you the center-line could change when you offset the TS to cut a tapered shaft.

The TS should be .001" high on HS side. but I would not try to estimate this until you have the mounted.

Now if you wanted to do it right but a lot harder, you would finish the TS first and lower the HS to the TS.

If I remember right your plan for the lathe was to turn farm machinery shafts? with a tolerance of a couple of thousands. If that was the case the TS should be OK as is.

I sure love your home and what a lovely family. :-) Rich
 
I would never re-bore the hole to fix a FK up on the ways.
I guess what I'm asking is sort of the opposite of this. Is it acceptable to FK up the ways to avoid reboring the hole? Generally I don't like the sound/thought of doing this but there are 2 things that keep driving me to this. The FK up in the ways would actually be tipping the head-stock end of the tailstock higher, so that as it wears it will start to droop back down to straight/flat. If wear/droop ever becomes a problem in the future, I would likely do the rebore and chrome/grind the quill then, and the tailstock bottom should just need a small bit of touch-up. The other driving factor is that I'm not sure my expected use justifies a better fix.

How else do I fix the droop in the quill? It does have some wear; it's not loose per-se, but it's definitely worn and sagging a bit.


If I remember right your plan for the lathe was to turn farm machinery shafts? with a tolerance of a couple of thousands. If that was the case the TS should be OK as is.
Multi-purpose... No super-precise work, but at the same time, I don't want to leave "easily achieved" precision on the table if that makes sense. My long-term plan is to get a good little side-business going but I'm not sure it would ever become more than that. One of my hobbies is guns and I've already done quite a bit of smithing; I plan to get my FFL and do some side-business gunsmithing. I do quite a bit of machine work for my dad too, he has machines but not the size/capability of mine so he normally brings me work that he isn't comfortable doing on his machines.

I sure love your home and what a lovely family. :-) Rich
Thank you!
 
That's why a few pictures would be nice. Have you locked the TS quill and tightened the TS to the bed before testing this? I have only seen 1 lathe in my many years with the TS after wear pointing up, and that must have been a FK up from the factory. Did you stone everything? Being a rookie...I suspect your indicating something wrong....call me later in the week...something doesn't make sense and maybe we can do a better job trouble shooting it on the phone.
 
Going for a "90% rebuild" on my LeBlond and the tail-stock is in need of some truing up. The base droops about .009" from one end to the other. Putting an indicator on the quill gives me .018" droop (when adjusted for the length of the tailstock base).

I have no plans/interest (due to cost) of sending the quill out for chrome & grind along with reboring/honing the bore. If anything I would prefer to bore & sleeve the tailstock. But in all reality, I think the bore is acceptable to just leave it go. It's a bit on the loose side but not unworkable. Suggestions on more budget friendly fixes to the quill/bore?

The base definitely needs trued up. If I do all of the realignment of the quill by scraping the base then I have a lot of material to remove and it will actually cause the joint between the halves to be tipped back a bit. This isn't entirely bad because as the front wears down it will tip back down. But it won't be right. To get it "right" I will have to do something with the quill & bore.

My plan was to scrape true and glue a phenolic shim between the halves but I'm now wondering if that's an acceptable plan.

This rescrape/rebuild job will likely last this lathe the rest of it's lifetime, I'm not looking for overkill, just looking for functional fixes that aren't a major sin or travesty when it comes to rebuilding.

There aren't any real short cuts to getting your tailstock back into line. You need to scrape the ways on the bottom half parallel to the bed ways. Four zeros on all four corners. If you're really clever you can scrape the tail stock bottom so the end nearest the headstock is up by 0.0005".
You can then machine or scrape the top face of the bottom half so the upper half of the tailstock sits nicely on the bottom half. Normally what happens is the tailstock wears downwards so you usually need to machine the bottom enough to allow you to screw and dowel plates onto the bottom half to raise the upper half back onto centre height.
Glueing a loose shim in place doesn't really do it for me. A 3/16" or 1/4" plate is much better.

I'm a bit confused as to how you are arriving at your readings ? This is were a test bar is invaluable. Failing than you can run a DTI along the top and side of your tailstock barrel. In an ideal world the barrel needs to to point towards you at the free end 0.0005" to 0.001" and point up at the free end by a similar amount.

Regards Tyrone.
 
Ugh, lost this all the first time... sometimes I hate PM's forum software...

Now with pictures. Note: I just slapped the parts together for a photo-op. Original measurements were taken with quill in fully extended position (but not over-extended as shown), with tailstock properly bolted down, and I printed the base on the ways to make sure there were no warpages that would skew measurements.

First 3 pictures are self-explanatory.
20171025_1800142.jpg20171025_180122.jpg20171025_180105.jpg

I know how to fix the quill that is pointing backwards. I know how to do the spud test and get the quill up to the proper height after everything is straight. What I don't know how to do is get the quill aligned without reboring/honing the bore and sending it out for a chrome & grind job.

What I'm asking is, would it be acceptable (although not "proper") to remove material from the base (bottom, the part that rides on the ways) as this picture shows.
20171025_180014.jpg
This would make the right end of the base lower than the left (headstock) end by ~.010"; it would tilt the entire tailstock to the right a small amount, fixing the droop in the quill. Then the whole thing would need shimmed; I plan to glue phenolic shims in place as suggested by Rich in another tail-stock realignment thread.
 
Ugh, lost this all the first time... sometimes I hate PM's forum software...

Now with pictures. Note: I just slapped the parts together for a photo-op. Original measurements were taken with quill in fully extended position (but not over-extended as shown), with tailstock properly bolted down, and I printed the base on the ways to make sure there were no warpages that would skew measurements.

First 3 pictures are self-explanatory.
View attachment 211294View attachment 211295View attachment 211296

I know how to fix the quill that is pointing backwards. I know how to do the spud test and get the quill up to the proper height after everything is straight. What I don't know how to do is get the quill aligned without reboring/honing the bore and sending it out for a chrome & grind job.

What I'm asking is, would it be acceptable (although not "proper") to remove material from the base (bottom, the part that rides on the ways) as this picture shows.
View attachment 211293
This would make the right end of the base lower than the left (headstock) end by ~.010"; it would tilt the entire tailstock to the right a small amount, fixing the droop in the quill. Then the whole thing would need shimmed; I plan to glue phenolic shims in place as suggested by Rich in another tail-stock realignment thread.

Overthinking this, perhaps?

The most-common legitimate use of a handwheel TS ever BEING extended near-as-dammit full out is following a drill. Now "following" their own generated hole being what drills DO, it should lift that barrel to essentially centered .. providing.. the barrel is close enough to centered when the hole is started.

Same again as to fore and aft side pointing as up and down.

So.. the question is.. just how far off a "perfect" line is it when between half-inch and first inch extended rather than full-out?

Page Two:

Taking as a "given" that drilling is better done from the carriage ANYWAY when all one has at the TS is a one-speed handwheel. The real purpose of a basic handwheel TS is 'tween centers turning .

just how often do you even DO that, and if "not often", is it again "good enough" when not hung way-to-hell OUT? Or is even a simple shim at some o'clock point 'tween dead or live centre shank and bore taper good enough?

JMNSHO, but ... I'd not dick around with "point it up" (only).

EITHER ....go whole-hog, do it "by the book", and strive to make it perfect as can be, line-bore in-situ and all. if you make a NEW oversized barrel, no hard-chrome and grinding required.

ELSE .. leave it as-had, compensate now and then, and put your time, money, and search for improvement into something else that pays better and more frequent dividends.

A ram-lever/capstan one-holer, or a hex bed turret I can see chasing the gain.

An ignorant one-hole, one-speed handwheel TS? Not all that useful to begin with.

Personally, I can't be bothered. It just isn't that hard to compensate for imperfections, nor as often needed.

2CW
 
The most-common legitimate use of a handwheel TS ever BEING extended near-as-dammit full out is following a drill.
Never used a tailstock to support a workpiece on a lathe using a QCTP and a tool mounted on the left side of the TP? Gonna need a bit more clearance for the saddle to move further right; gotta extend that quill a little bit...

I do get your point though. I'm simply asking the advice of others. I appreciate the advice to just do nothing, but I will likely do something at minimum.
 
Never used a tailstock to support a workpiece on a lathe using a QCTP and a tool mounted on the left side of the TP? Gonna need a bit more clearance for the saddle to move further right; gotta extend that quill a little bit...
4-way, rather, but surely. OTOH, I was usually turning a bearing fit. Compensating and sneaking up had to be done, regardless. Talking War-One Niles heavies, here, and not allowed to "fix" FUBARED TS. Union Shop, "company" lathe, not in my "classification". Whether I knew HOW to repair the TS or not, it wasn't permitted.

I do get your point though. I'm simply asking the advice of others. I appreciate the advice to just do nothing, but I will likely do something at minimum.

Not quite. What's to "get" is that "something at a minimum" is to be avoided. Effort invested is a loss. It can make a PROPER restoration harder later than if left alone.

Either "do it right" - go all the way- or "not at all" - continue to compensate.

The in between path is the time-waster where the patch attempts to correct one error by introducing another, countervailing error.

Works well for Government Accounting. Not so well for machine tools.
 
It can make a PROPER restoration harder later than if left alone.

Is this the only downside other than the "loss of time" of which you speak? My proposed solution arrives at the same end (functionally straight quill), by a different means.

I will likely never have to do the proper repair; getting a functional solution will likely last the rest of the life for this lathe.

I would beg to differ that it makes the proper repair harder. It will start the left end of the tailstock base higher than usual, and as it wear it will come down a bit, bringing it back closer to level/true. If it were to be repaired in the future it would likely require a rescrape in addition to the quill work; I would just be rescraping the left end down (and leaving it a bit high) instead of the right end...

Or I can just put it back how it was; .030" of steel shims in the left side and .020" in the right, check true of the quill and it will likely be good for the rest of it's life in my shop. It likely needs closer to .050 in the left & .025 in the right but I have to do a proper spud test to know for sure.
 
I plan to glue phenolic shims in place as suggested by Rich in another tail-stock realignment thread.

I'm curious how well this will work and would appreciate if you'd report back. I don't think it's going to work but would like to be proven wrong.
 
I'm curious how well this will work and would appreciate if you'd report back. I don't think it's going to work but would like to be proven wrong.

I'm open to suggestions, it was suggested by Rich in another thread I read... I would think a good steel shim glued in place would be better but the reality is that I will likely never slide the tailstock for turning between centers so whatever shim material I choose shouldn't be an issue staying in place. It will be used primarily for drilling and live-center support but will also be used to for chamber reamers (chambering barrels) and other odds and ends.
 
I'm open to suggestions, it was suggested by Rich in another thread I read... I would think a good steel shim glued in place would be better but the reality is that I will likely never slide the tailstock for turning between centers so whatever shim material I choose shouldn't be an issue staying in place. It will be used primarily for drilling and live-center support but will also be used to for chamber reamers (chambering barrels) and other odds and ends.

I've no idea and I'm quite curious what results you are going to get. There is a lot of force on the t/s sometimes and they do tend to wear convex which aggravates things. I'd also think that steel or CI plates, or brass, might be better. I think I read somewhere that brass can be glued properly to CI.
 
I was taught to use Phenolic* shimming from my father 50 years ago and have been doing it and have never had a customer complain. I would never use a thin steel, brass, plastic shim stock glued on unless it was a super emergency break-down. All situation are different. 3 or so years ago I glued Phenolic if I recall was .062" under Drake CNC Thread Grinders to bring worn sliding head and tail stock back to the original center-line. (ill add some pictures in a bit) It worked for my Dad 50 years ago on similar projects. I can imagine he learned the technique from his German Journeymen who he learned from in the 1940's. It works as does other methods. I don't have to guess if it will work as I know it will work in static and sliding components.

Also the technique of turning a plug in the machine the same size as the TS quill is something I learned from him. So much faster to calculate the off-sets and height then using a test bar. Country boy is getting ahead of himself here when he doesn't have the head stock assembled. But he is a graduate Engineer who is curious and getting some idea's. More power to him! I am not suggesting gluing on a .005" Phenolic shim I would machine off clearance and use a minimum of 1/16".

So many things are misconstrued or twisted on here, he said this and he said that and (whine) because who read it did not understand what someone meant. That is why the hands on classes are so much better.


** Only use "GRADE" or type Linen Phenolic. I worked in the early 70's with a project engineer who converted Cinc. Hydrotels to NC who had huge problems at Bendex when they used paper phenolic instead of linin.
I have used canvas phenolic in a pinch, but the weave is much coarser. Grade Linen Phenolic is the best method.
 
I just went back in my rebuilding pictures and I rebuilt the first Drake in May of 2012. I will attach a few pictures. After looking at the pictures I didn't glue the Phenolic to the ways. These machines were built by Drake Mfg and they used old Jones & Lampson Thread Grinders. You will see how they bolted steel plates to the bottom of the Head-Stock and Tail-Stock to align the HS & TS to the Wheel Head Centerline. I put the Phenolic under those plates to bring the worn table I had to scrape and the worn HS & TS back to the wheel head centerline.

I didn't take enough photo's as I never intended to put them on here. Also note how I used the King-Way on the slant table to test the Stocks and check the parallelism of the table with the single bubble using the indicator clamp to test the parallelism of the table top. I had to scrape it and the guiding edge of the table to be aligned zero zero to the wheel.
In the lathe tail-stock as this grinder tail-stock I instruct gluing the Phenolic in between the bottom and top half's where it is a static fit.

Lowering the top of the test bar change the height of the center line top and side of the test bar. It was a real nightmare to get both top and side of both head-stocks aligned to .00005" or less. I scraped them to as close to perfect as I could. Not something I would recommend a hobbyist or young apprentice do.

2012-05-18_08-41-15_283.jpg2012-05-18_08-41-46_909.jpg2012-05-18_08-40-57_631.jpg2012-05-18_08-41-06_622.jpg2012-05-16_19-02-55_322.jpg
 

Attachments

  • 2012-05-16_19-02-55_322.jpg
    2012-05-16_19-02-55_322.jpg
    90.9 KB · Views: 188
Last edited:
For those who are new to the Forum like Alex. I am not guessing or asking the readers how to do things as I am a Professional Machine Tool Rebuilder with my lifetime of learning experience. I come here to offer free advice to pass on my lifetime of experience.

As a professor who called me a few days ago and asking me "how to scrape the ways of a surface grinder". He said I was all over the internet with good advise. I have also taught in Istanbul Turkey at a new machine builder called Spinner, Worked in Taiwan for the Taiwanese Industrial Machinery Industry to teach how to BUILD new machines. I started to teach there in 1980's and over the last 30 + years returning there several times and was awarded for my teaching there. I have worked and taught at with 8 divisions of GMC, Rolls Royce, Hardinge and several USA based new machine builders such as Drake when I taught scraping classes there in the 1990. I taught classes for the USA Navy at 4 Naval shipyards. Ask Forrest Addy as I taught at his shipyard in the 80' and 90's. They hired me to TEACH Scraping and Rebuilding!! In recent years I have taught in Scandinavia and Germany. I will be leaving to teach in 3 Machine tool Rebuilders shops in Germany in a couple of weeks.

Pic's L to R. The Machine Rebuilder I taught at in Germany last trip, Pic 2 and 4 My award I received in Taiwan, the classroom we used in Taiwan to teach several hundred students, All my students will recognize the set-up as it's the same style I have used for years. What was nice at PMC the research institute I worked at they made the scissor tables to adjust to the right height for different students. You can see more info of my classes and the classes my assistant teachers now teach after I trained them at PMC web-site and face book page.

I just looked at the PMC Facebook page and stated clicking on Chinese characters and up came the DVD introduction we played to all the new students in the classroom. Everytime I watched it I would tear up and felt humbled. Even though the captions are in Chinese bare with it. They talk about the masters and their "art" Lost arts of old and new. About 1 minute in they start to show scraping and talk about our art and show me teaching it. They also show pages out of the Moore book "The Foundations of Mechanical Accuracy. Show the BIAX Scrapers, etc. The music is in English. There reference to the Christian faith is they explain how lasting it is and the church or congregation of the followers of the religion is like the followers of scraping. Enjoy.

鏟花及鏟配技術發展社群 - 基礎鏟花班開幕影片


鏟花及鏟配技術發展社群 - Home | Facebook If you scroll down to the bottom of the pictures you will see me.
http://scraping.pmc.org.tw/share.php?display_type=detail&share_id=2
or check out: scraping.pmc.org.tw
 

Attachments

  • DSC03005.jpg
    DSC03005.jpg
    39.8 KB · Views: 78
  • TAMI Gift.jpg
    TAMI Gift.jpg
    39.6 KB · Views: 78
  • IMG_20140816_195822~2 (2).jpg
    IMG_20140816_195822~2 (2).jpg
    100.8 KB · Views: 84
  • Tami award.jpg
    Tami award.jpg
    43.8 KB · Views: 77
  • my class.jpg
    my class.jpg
    93.7 KB · Views: 140
Last edited:








 
Back
Top