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Tailstock height adjustment (Schaublin 102)

Luke Rickert

Hot Rolled
Joined
Oct 24, 2007
Location
OSLO
I am considering the options to repair the wear to the non-adjustable schaublin 102 tailstock. I can scrape it flat and true but that will lower the center line and I don't really want to mess with re-scraping the head stock as well given it is static. We are not talking about a huge amount of wear, maybe 0,02 mm (basically 1 thou for you inch guys) over the bottom of a small tail stock.

The options as I see it now,
-Not worry about it, it works fine for drilling and good enough with the center for most applications and this isn't the machine I am going to use for long parts given it only has 90mm's of travel with the carriage.
-I can mill out the bottom of the tail stock and install either Moglice or thin cast iron with glue or brass screws and scrape it in. This is basically a static part so I don't want anything too slick in there (Trucite) as it won't hold when I try to drill etc.
-Other have suggested making a new ram or re-boring the tail stock but that seems like a terrible idea to me. The ram is super-finished and crazy true, I could never make another without some very special equipment.

Thanks

Luke
 
It's pretty common to find someone has slipped a shim between the base of the tailstock and the upper body. There is a joint where the tailstock is adjusted side to side. My dad has a lathe with a brass shim under the flat way to prop it up just a bit.

Some CNC lathes have a shim built into the tailstock for setting the height. Since they tailstock ways are usually slanted or cantilevered of the base casting, they make things easier for themselves by using a shime that can be ground to fit.

Personally, I would not lose sleep over .001. But, it's your machine.
 
I am considering the options to repair the wear to the non-adjustable schaublin 102 tailstock. I can scrape it flat and true but that will lower the center line and I don't really want to mess with re-scraping the head stock as well given it is static. We are not talking about a huge amount of wear, maybe 0,02 mm (basically 1 thou for you inch guys) over the bottom of a small tail stock.

Luke

If I were you Luke I'd leave alone unless you are doing very precise work ... how accurate is the drill arbor in the tailstock?

Just my two pence / Krone worth of course.

John :typing::cheers:
 
I have re-bored one tailstock for a 70 and years ago for one 102. For the 70 I have described my procedure, in this forum some month ago. For the 70 I made sleeves as was lapped. Then I also lapped the original quill and re-used it. Very good result. For the 102, I re-bored the tailstock and a friend made an oversized quill for it. It was more of work and the result was good. The method I have described for the 70 is not hard to do if you can borrow an other tailstock or you have a steady rest.
 
The accuracy of the center height is more of a concern than drilling as that isn't all that accurate anyway although I do end up needing to make tiny (less than 0.5mm) holes on occasion. If I am turning between centers or just using a center for support a 0.02mm drop is enough to be a problem or at least annoying :)

What I should probably do is find another worn trail-stock and mill out the bottom, graft in new iron and scrape it in level and straight without messing up my current one any more than it is.

Luke
 
A google image search indicates that your tailstock is one piece with no split where the tailstock can be adjusted side to side. That definitely limits your options.
 
You might look into thermal metal spray for cast iron. I am not sure where the technology is as far as machinable cast iron build up, but I've heard of some applications being useful.

Much the same as getting the part plated. Hmm... electroless nickle is a DIY operation.

Then too, there are the "brush" plating methods.
 
Personally I think your being too picky; reason is a brand new 13" tool room lathe is sent out with tail stock .002" higher than the head stock? Didn't make a lot of sense to me, seemed like it would be breaking drills or something but I've drilled several times diameter/depth and has never been an issue.
It has never been a problem while turning either. I realize they are different class lathes so there may be a difference but still wonder what the specs are for a brand new 102?
Dan
 
I would first ask how did you discover it was .001" low?

Have you read how I teach to test the TS Vs. Headstock? It's simple and works good. Measure the quill and the
chuck up a spud or one off .125" or so bigger and sticking out of the chuck say 4", Then turn it down to the exact size of the quill, Then mount a mag base on the compound or cross-slide and sweep the top to get top dead center of the test spud and then crank the carriage to the right and measure the top of TS quill and see how its pointing. If it is truly low, then to speed up the work, temporarily shim up the front and if it takes .0005" or .001 or .002". The shim is temporary and is used to eliminate the math of length of TS to Length of quill area tested. Then remove the shims and step scrape the right side down to tip up the quill. There might be a burr in there too, have to be a detective and figure it out. :-)
Many times the TS is pointing down and you can scrape off the right end of the TS and tip it up. If it' is only .001" that should be simple to step scrape. If you look at the thread I did on the Keith Rucker GA class, I link to a You Tube where one of the guys explains step scraping. Be sure the middle 40% is relieved about 2 scrapes of the blue spots so the bottom of TS isn't rocking like a rocking chair too. Square cutting or checkerboard Scraping the bottom would also give it new oil pockets too. Rich
 
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Personally I think your being too picky; Dan

Not really :) The point of these machines is to be extremely accurate, they don't cut threads, they don't take heavy cuts or remove tonnes of material, they don't have power feed or even lead-screws for that matter, they do however make very very accurate cuts on small to medium size parts. The original paper work from 1973 for my particular machine said that the tail-stock was 0,001mm high over the 100 mm's of the ram and that it was within 0,002mm in the horizontal direction. The headstock was also 0,001 mm high. With careful scraping I can get it back close to that but as the center-line is fixed I can't scrape it all down so I need a way to get new material in there. Ideally I need to add a material I can scrape and one that will work as a clamping surface which really means cast iron I think.

It is worth noting that Schaublin didn't use fitters, all the parts such as the non-adjustable Schaublin 102 tail-stocks from a production run of over 80 years are interchangeable. They didn't mess around.
L
 
I am considering the options to repair the wear to the non-adjustable schaublin 102 tailstock...

I have the same problem as the O.P. and have not yet got around to resolving it. I want to move forward with this project now.

My Schaublin 102N came with a star wheel tailstock. I later found a used MT2 tailstock of correct vintage. My MT2 tailstock sits about .006" too low. Thats WAY too low.

BTW: The method I am using to check the alignment is the one recommended in the "Machine Shop Secrets" book: Chuck a test indicator in the spindle and sweep the bore of the tailstock ram.

Here's my original thread on the topic (2009):

http://www.practicalmachinist.com/v...recommend-u-s-scraping-shop-schaublin-184285/

In 2015, Dr. Samways of Anglo-Swiss tools in UK suggested a method he has used successfully. In brief, it involves milling pockets in the sole of the tailstock and milling down the side "cheeks". Then thin cast iron plates are installed. The plates for the sole of the tailstock are bonded in place and then ground.

The ones for the sides are mounted on dowel pins so that set screws can be used to adjust alignment. So the side pieces are essentially gibs.

Here's my second thread on the same topic years later (2015). The method above is described in post #12.

http://www.practicalmachinist.com/v...athes/schaublin-rebuilder-los-angeles-303222/

The time has come to get this done. It is a matter of sorting out all the details:

What kind of iron to use for the new plates, and where to source it?

How to hold the tailstock for milling the pockets? (easier on my tailstock because it's the flat-topped 102N style)

Where to get the iron plates ground down?

Where to get the tailstock fitted by final scraping to align it to the headstock?

I imagine that the best procedure would be to grind the tailstock with new iron plates until it sits slightly high (like .001" / .025 mm) and then make the final adjustment by scraping and by adjusting the set-screw side pieces.

I'm located in Burbank (North Los Angeles area). If anyone has any recommendations for a place to get the tailstock ground (and possibly get the bed ground perfectly flat while at it) and then have the tailstock scraped into alignment, I would greatly appreciate it.

Thanks in advance...
 
I have the same problem as the O.P. and have not yet got around to resolving it. I want to move forward with this project now.

My Schaublin 102N came with a star wheel tailstock. I later found a used MT2 tailstock of correct vintage. My MT2 tailstock sits about .006" too low. Thats WAY too low.

BTW: The method I am using to check the alignment is the one recommended in the "Machine Shop Secrets" book: Chuck a test indicator in the spindle and sweep the bore of the tailstock ram.

Here's my original thread on the topic (2009):

http://www.practicalmachinist.com/v...recommend-u-s-scraping-shop-schaublin-184285/

In 2015, Dr. Samways of Anglo-Swiss tools in UK suggested a method he has used successfully. In brief, it involves milling pockets in the sole of the tailstock and milling down the side "cheeks". Then thin cast iron plates are installed. The plates for the sole of the tailstock are bonded in place and then ground.

The ones for the sides are mounted on dowel pins so that set screws can be used to adjust alignment. So the side pieces are essentially gibs.

Here's my second thread on the same topic years later (2015). The method above is described in post #12.

http://www.practicalmachinist.com/v...athes/schaublin-rebuilder-los-angeles-303222/

The time has come to get this done. It is a matter of sorting out all the details:

What kind of iron to use for the new plates, and where to source it?

How to hold the tailstock for milling the pockets? (easier on my tailstock because it's the flat-topped 102N style)

Where to get the iron plates ground down?

Where to get the tailstock fitted by final scraping to align it to the headstock?

I imagine that the best procedure would be to grind the tailstock with new iron plates until it sits slightly high (like .001" / .025 mm) and then make the final adjustment by scraping and by adjusting the set-screw side pieces.

I'm located in Burbank (North Los Angeles area). If anyone has any recommendations for a place to get the tailstock ground (and possibly get the bed ground perfectly flat while at it) and then have the tailstock scraped into alignment, I would greatly appreciate it.

Thanks in advance...

I may sound like a broken record, but... when the "plate" needs to be THIN, I use BRONZE. CI should warp - as it tends to do when trying to make thin plates of it - you may or may not be able to straighten it w/o breaking it. Bronze, one can press back straight, and with near-as-dammit NO risk of breakage. It also wears well. "Well enough", anyway. Too MUCH wear? Easier to replace, too.

Production of "wear strips" of various bronzes for sliding fits is a major industry in its own right. Plenty of suitable material out there. Application techniques as well.

Uber-plastics - such as Rulon, Turcite, Moglice & Sputniks work too. Some even have bronze IN them. Just not what I want if I can do the do with solid metal. In thinner section. Without need of milling "minimum clearance" for a bonding adhesive.

YMMV, Do your Own Due Diligence, etc.

2CW.

Oh.. BTW... six thou? Trim a strip of foil or brown Kraft paper.

Slide it down in the taper as you seat the centre. "Sweep" that. Temporary magic.

That can get a job DONE whilst one spends two-plus years plotting and scheming a better solution.

"Company" lathe, one had no other options, y'see, so about a gadzillion machinists HAD TO learn those tricks on wore out War-One era Niles and such over the last hundred years or so.

"Insult" to a Schaublin, such up-holler hillbilly tricks?

Yeah, but... the little buggers were as "perfect" as some folk expect, their TS centre would never have moved off "zero" error in the first damned place, now would it have?

:D
 
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I have the same problem as the O.P. and have not yet got around to resolving it. I want to move forward with this project now.

My Schaublin 102N came with a star wheel tailstock. I later found a used MT2 tailstock of correct vintage. My MT2 tailstock sits about .006" too low. Thats WAY too low.

BTW: The method I am using to check the alignment is the one recommended in the "Machine Shop Secrets" book: Chuck a test indicator in the spindle and sweep the bore of the tailstock ram.

Here's my original thread on the topic (2009):

http://www.practicalmachinist.com/v...recommend-u-s-scraping-shop-schaublin-184285/

In 2015, Dr. Samways of Anglo-Swiss tools in UK suggested a method he has used successfully. In brief, it involves milling pockets in the sole of the tailstock and milling down the side "cheeks". Then thin cast iron plates are installed. The plates for the sole of the tailstock are bonded in place and then ground.

The ones for the sides are mounted on dowel pins so that set screws can be used to adjust alignment. So the side pieces are essentially gibs.

Here's my second thread on the same topic years later (2015). The method above is described in post #12.

http://www.practicalmachinist.com/v...athes/schaublin-rebuilder-los-angeles-303222/

The time has come to get this done. It is a matter of sorting out all the details:

What kind of iron to use for the new plates, and where to source it?

How to hold the tailstock for milling the pockets? (easier on my tailstock because it's the flat-topped 102N style)

Where to get the iron plates ground down?

Where to get the tailstock fitted by final scraping to align it to the headstock?

I imagine that the best procedure would be to grind the tailstock with new iron plates until it sits slightly high (like .001" / .025 mm) and then make the final adjustment by scraping and by adjusting the set-screw side pieces.

I'm located in Burbank (North Los Angeles area). If anyone has any recommendations for a place to get the tailstock ground (and possibly get the bed ground perfectly flat while at it) and then have the tailstock scraped into alignment, I would greatly appreciate it.

Thanks in advance...

I suggest you first grind the bed and then worry about the tailstock. Getting the headstock ( spindle ) parallel to the bed is a much harder proposal - you need to sort that one first. You have two option re. the t/stock : add something to lift it up or rebore and hone and make another quill. The 2nd option works wonderfully but it's not going to come as cheaply. There is a 3rd option which will draw the wrath of the board upon me :) : make an entirely new t/stock similar to a dividing head one. Fully adjustable. It's a small lathe...
 
There is a 3rd option which will draw the wrath of the board upon me :) : make an entirely new t/stock similar to a dividing head one. Fully adjustable. It's a small lathe...

Fourth option for "light lathes" - given that I drill from the carriage, not TS, anyway.. is to pull the 5/8" straight shank (four machine screws thru a flange) off one of the several surplused Hardinge turret cross-slides out there (I have three types arredy), replace with a MT tail.. and dial-in your center, straight OR set-over for taper turning. (One of) your (several) stub centers can be a ball-ended one if tapers are on the dance-card.

Needs torque management, plus a bit of "vector analysis" when correcting for both height and CL offset, but neither of those are rocket science.

Unlike the DH centre, one CAN drill with such a rig, but ..a "conventional" handwheel TS is borderline useless for REAL drilling, anyway. Can't clear chip fast enough.

Carriage-mounted drill can do. Adds powered advance and (usually) longer stroke as well.
 
A Thou does not sound like a lot, but it depends on part size. What diameter parts do you do between centers?

Do the math and see if the error is even an issue.

I did a quick calculation and came up with a diameter error of 0.00004" on a workpiece of 0.03", which is about .001mm on a 0.75mm diameter part.

Your actual error is slightly less, as 0.02mm is 0.8 of a thou.

I suppose if you just have to, you could scrape it flat and aligned, then give it a heavy plating, and you'd likely no be able to measure the resulting error. But Schaublin or not, it's hardly any error as it is.... Seems like it is way down in precision grinder territory, the surface finish from turning should be larger..
 
Oh.. BTW... six thou? Trim a strip of foil or brown Kraft paper.
:D

That's what I did, made from brass shim stock. PITA to work with though. Really sucks when you have to slide the TS back and forth on the bed. AND I had to use a stack .005 and a .001 shim. AND you have to shim on the sole and on the side angles.

BTW, what are the advantages of bronze over brass? Not arguing, I know bronze is preferred in certain applications and want to know more.

P.S. I work in a very precision application with shims all the time: Adjusting the back focus of cine lenses. I aim for a focus tolerance of .002 mm and tolerance is generally +/- .005 mm.

There are always variables with shims, especially multiple shims. They can wrinkle, they can be sensitive to pressure (the shims sit between flanges pulled together with screws the torque on the screws - usually M2 screws - affects focus).
 
BTW, what are the advantages of bronze over brass? Not arguing, I know bronze is preferred in certain applications and want to know more.

There are hundreds of formulations of each, but basically, "Brass" alloys Zinc with Copper. Sadly, Zinc is an electrochemical WHORE of first-order. All-too-willing to combine with ANYTHING gaseous, liquid, or solid. That makes it a good sacrificial Anode on boats or pipelines, but not so good for moving parts in machinery. It can be leached right out - even by Chlorinated tap water, let alone more aggressive-yet coolants - leaving a weak matrix of red copper.

Bronze historically relies on Tin as the major alloying element with the Copper. It is more durable in that "chemical" realm, plus has a number of OTHER nice attributes. Some bronzes don't even use much tin. Several are stronger than common steels.

Aluminium Bronze and Nickel-Aluminium Bronzes are what they sound like. Damned tough cookies, too, and not all that easy to machine.

Oilite 16 Bronze, an uber-performer for certain types of bearings, one has to go and look-up.

It is ~35 percent void for oil-fill or thru-flow, much as its more common Oilite "one" Daddy. Chrysler creations, originally, BTW. Early 1930's.

But..Oilite 16 is predominantly Copper and IRON - no significant Zinc OR Tin. Properly Engineered in, it can stand some seriously high loading for a longish time.

The "Bronze Age" didn't exactly end. New and clever things are still being added to its arsenal. Have a look at K.C. Jones "Miccrolloy" plating in serious thicknesses:

Miccrolloy™ Bronze Plating | KC Jones Plating: Zinc Nickel Plating, Zinc Plating, Electroless Nickel Plating

So....Bronze didn't "go away". It just gained competition from Iron and its alloys is all. Armaments for Rome's Legions one of the first major "design wins". Didn't prevent George Armstrong Custer and krew being done-in with weaponry that still included flint arrow and spear heads, though. Stone age hadn't run out of uses for stone, either. Got three surface plates here, a tiny DoAll lab / inspection AA grade, a B&S Grade B, and a Herman Grade A.

Three different Granites.

:)

And then.. we got into Nickel, Chromium, Cobalt, Tungsten, Molybdenum... and more...

"Interesting times", metallurgically, these last few thousand years...
 
I suggest you first grind the bed and then worry about the tailstock. Getting the headstock ( spindle ) parallel to the bed is a much harder proposal - you need to sort that one first. You have two option re. the t/stock : add something to lift it up or rebore and hone and make another quill. The 2nd option works wonderfully but it's not going to come as cheaply. There is a 3rd option which will draw the wrath of the board upon me :) : make an entirely new t/stock similar to a dividing head one. Fully adjustable. It's a small lathe...

Or, even more wrath: manufacture a new quill for the tailstock, bore the end of it off-center to bring the center up where it belongs.

The issue of getting the axis of the tailstock correct on a machine like this (fixed base TS) is pretty daunting.

It has to be correct height - ie the headstock spindle axis height.
It has to be parallel to the bed (or more accurately to the headstock spindle axis) in the horizontal plane
It has to be parallel to the spindle axis, the vertical plane

And if it 's a reverse dovetail bed, then the TS dovetail has to bear on the flat, and two angled sides, simultaneously as well.

This is one reason, I think, that schaublin 70s have TWO bearing surfaces, the top of the bed and only one side of the bed,
and those are at 90 degrees.

Pondering all this, I consider it amazing that nearly all the bench lathes of the early 1900s were made with just this crazy
setup, reverse dovetail ways and fixed, not split, tailstocks. They must have paid precision hand scrapers about ten
cents an hour.
 
Calling Diamant and having a chat about the various options is on my list of things to do. I think some sort of metal filled epoxy that isn't as slippery as moglice would be the best option provided it is scrapable (I think that would be a flavor of Plasticmetal). The idea of messing around to plates of bronze, adjustment screws etc on three difference surfaces just seems fussy. I would rather mill off the bottom 10mm and screw on a new section of cast iron and scrape that (bottom and sides) in correctly but before that at least trying epoxy of some sort seems like a good option :)

L
 








 
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