Thread: TOS SN500S Spindel aligenment

Hello

I bought a tos sn 500s lathe that had a few problems.

Ive leveled the lathe fairly good and it still turns a taper of 0.15mm over 120mm right infront of the spindel. that tells me that the spindel is out of aligenment right?

I put in a new 3 jaw chuck because the old one was junk.

so the question is anyone know where there is some adjustment for the spindel on the lathe? i got some manuals but nothing about it in thoes.

i will see if i can snap some pictures on the lathe today

Most lathes have this issue. Many times you can twist the bed out of level / alignment so the lathe cuts true. You need to look up "The 2 Collar" test and measure it with a micrometer as that is how you measure turned parts the way your testing it with an indicator. Once you twist the bed, you have to boreon the opposite side of the OD because your doubling the error if you bore on the ID. You will also have to file or emery cloth the misalignment of a long shaft between c has a great enters. Once you do the 2 collar test and if let us know and if that does not work if it is worn to much then you can consider shimming the head. In 50 years of doing lathe alignment I can count on 1 hand I shimmed a head. Twisting bed it what I have done. You can look on You Tube and Abomb 79 (Adam booth) has a super show on doing this. If you do shim the head be sure to clean the lathe. No need to reinvent the wheel doing this proven method.

On the Tos SN40 and 50 which has some simularity the headstock is adjustable It stands on a scraped flat and has 1 pivoting point and 2 bolts (in the side IIRC) to push the headstock sideways a bit (You have to loosen some hold down bolts inside the gearbox of the headstock) It is not standing on the V of the ways

This one seems to be standing on the front V of the bedway so you would think it is not adjustable
But sometimes the V of the headstock is wider and filled up with a filler like SKC
I would check that out Also look into the gap where that little sheetmetal below the chuck was bolted to the casting to see whats behind Sometimes you find adjustment screws there
If the bed is leveled properly the next thing to do is align the headstock to the leveled bedways Not twisting the bedways out of alignment IMHO The 2 collar test will be oke then but it will put the tailstock out of alignment at different distances
Wear of the bedways can be a gamebreaker though as you cannot level the lathe properly any more
Also 0.15mm over 120mm is so much that the headstock is suspect with a leveled bed
Just to make sure Your level is 0.02mm/mtr ??


Peter

Originally Posted by Richard King

Most lathes have this issue. Many times you can twist the bed out of level / alignment so the lathe cuts true. You need to look up "The 2 Collar" test and measure it with a micrometer as that is how you measure turned parts the way your testing it with an indicator. Once you twist the bed, you have to boreon the opposite side of the OD because your doubling the error if you bore on the ID. You will also have to file or emery cloth the misalignment of a long shaft between c has a great enters. Once you do the 2 collar test and if let us know and if that does not work if it is worn to much then you can consider shimming the head. In 50 years of doing lathe alignment I can count on 1 hand I shimmed a head. Twisting bed it what I have done. You can look on You Tube and Abomb 79 (Adam booth) has a super show on doing this. If you do shim the head be sure to clean the lathe. No need to reinvent the wheel doing this proven method.

i already did the two collar test with mic on the turned shaft you see in the pic. the indicator in picture was just to see if my ways was wacked or was parallel with the turned collars on the shaft.. and they where parallel.. that tells me that its the spindel thats out of wack.

i cant correct 0.15 millimeter over 100mm in the ways thats forsure.. the machine is to ridget for that.

Originally Posted by Peter from Holland

On the Tos SN40 and 50 which has some simularity the headstock is adjustable It stands on a scraped flat and has 1 pivoting point and 2 bolts (in the side IIRC) to push the headstock sideways a bit (You have to loosen some hold down bolts inside the gearbox of the headstock) It is not standing on the V of the ways

This one seems to be standing on the front V of the bedway so you would think it is not adjustable
But sometimes the V of the headstock is wider and filled up with a filler like SKC
I would check that out Also look into the gap where that little sheetmetal below the chuck was bolted to the casting to see whats behind Sometimes you find adjustment screws there
If the bed is leveled properly the next thing to do is align the headstock to the leveled bedways Not twisting the bedways out of alignment IMHO The 2 collar test will be oke then but it will put the tailstock out of alignment at different distances
Wear of the bedways can be a gamebreaker though as you cannot level the lathe properly any more
Also 0.15mm over 120mm is so much that the headstock is suspect with a leveled bed
Just to make sure Your level is 0.02mm/mtr ??


Peter

it is a 0.02/m and the ways are leveled all the way... yep 0.15 over 100 mm is alot.. that would not be a good idea to compensate in the ways.. i am sure its the spindel thats out of wack.. i just need to figure out how to move it..

Behind that sheetmetal was nithing i did check.. and i can see the the whole gearbox is standing in the V way

What does your handbook have to say about headstock alignment ? On most lathes on this side of the pond the headstock can be adjusted into true alignment. Although it may appear that the headstock casting is bedded to the vee ways usually there is a small amount of clearance that will enable you to correct alignment errors. A set of feeler gauges will soon tell you if the headstock casting is adjustable.

If it is adjustable there are pages and pages of advice as to how to go about adjusting the headstock.

Regards Tyrone.

I now remember having the same problem with a Weiler Commodor It had the same construction
It turned out 2 of the bolts that held the headstock in place were loose
See post 30 about it
Weiler Commador rumbling gearbox

Peter

Originally Posted by Tyrone Shoelaces

What does your handbook have to say about headstock alignment ? On most lathes on this side of the pond the headstock can be adjusted into true alignment. Although it may appear that the headstock casting is bedded to the vee ways usually there is a small amount of clearance that will enable you to correct alignment errors. A set of feeler gauges will soon tell you if the headstock casting is adjustable.

If it is adjustable there are pages and pages of advice as to how to go about adjusting the headstock.

Regards Tyrone.

Sadly i seem to be missing a manual about headstock adjustment.. i only got a little start/operating manual and a parts list manual.

Originally Posted by Peter from Holland

I now remember having the same problem with a Weiler Commodor It had the same construction
It turned out 2 of the bolts that held the headstock in place were loose
See post 30 about it
Weiler Commador rumbling gearbox

Peter

that might be the problem.. i dont think its easy to lift this spindel off.. and the bolts are not easy to access.

Can the problem be the way bridge under the spindel? there seem to be 0.05 lift there close under the chuck.

Maybe i should to removing it and see if there is some dirt under it.

Before you mess with anything else. Pull the gap out and clean remove burs. lightly stone mounting area etc....

Originally Posted by Nikolaiownz

i already did the two collar test with mic on the turned shaft you see in the pic. the indicator in picture was just to see if my ways was wacked or was parallel with the turned collars on the shaft.. and they where parallel.. that tells me that its the spindel thats out of wack.

i cant correct 0.15 millimeter over 100mm in the ways thats forsure.. the machine is to ridget for that.

As Forrest Addy say's everything is made of rubber. Nik, You are mistaken as I have twisted machine beds my entire 50+ years of rebuilding.

Originally Posted by Richard King

As Forrest Addy say's everything is made of rubber. Nik, You are mistaken as I have twisted machine beds my entire 50+ years of rebuilding.

Yes but then the tailstock is off by a couple of mm at the far end when correct at the chuck
The machine is level already acc. the OP

Peter

Tail stocks can be adjusted over to compensate. The machine is worn and you have to do a happy medium to make the machine better. If he was rebuilding the machine he could scrape the headstock and tail-stock. It appears he is asking us to repair it and not rebuild it. YouTube

YouTube Fast forward to 15 Min

It would be nice to know how the op leveled the machine, Ie which surfaces. If it was saddle flat to tailstock flat could double check riding the carriage and across the V tops (after checking them).
At a glance the ways look in great shape, turning .006" in 6" id expect them to be trashed. Looks like theres an area on the saddle V way thats not getting hit, could sweep those ridges for an idea of wear.


I dont like how the bar was clocked, be nice to have the indicator where the tool would be so you know what the tool sees.


IF:-
The ways are in good shape.
The bed is level.
The saddle isnt jacking off the gap or something else silly.
And the headstock turns out to be adjustable (which im thinking it likely is).

Its pretty obvious the headstock just needs a nudge over. Im sure no pro would torque the bed in that situation.

Tom chases his tail for a bit before bumping the HS.

Originally Posted by Peter from Holland

On the Tos SN40 and 50 which has some simularity the headstock is adjustable It stands on a scraped flat and has 1 pivoting point and 2 bolts (in the side IIRC) to push the headstock sideways a bit (You have to loosen some hold down bolts inside the gearbox of the headstock) It is not standing on the V of the ways

Could this be them?

Originally Posted by Demon73

Could this be them?

Possible Hard to say
But if he wants to go the route of adjusting the headstock he needs to remove the gearbox for threading anyhow
Then you can see more
It is just a matter of disassembling things for a hour or 2
Then you know something Now we are all guessing
If the OP is happy with twisting the bedways and adjusting the tailstock every couple of inches its moved I do not mind
But at least he knows the consequence of doing that now
That is not the way I should proceed
It is my firm believe the 2 collar test is for alligning the headstock once the bed is leveled
Not for aligning the bed Because there is no way to determin if the headstock is aligned to the bed
You have to be sure of the one to measure the other against
Not assume things

Peter

Originally Posted by Peter from Holland

Possible Hard to say
But if he wants to go the route of adjusting the headstock he needs to remove the gearbox for threading anyhow
Then you can see more
It is just a matter of disassembling things for a hour or 2
Then you know something Now we are all guessing
If the OP is happy with twisting the bedways and adjusting the tailstock every couple of inches its moved I do not mind
But at least he knows the consequence of doing that now
That is not the way I should proceed
It is my firm believe the 2 collar test is for alligning the headstock once the bed is leveled
Not for aligning the bed Because there is no way to determin if the headstock is aligned to the bed
You have to be sure of the one to measure the other against
Not assume things

Peter

i will not twist the ways for compensation forsure.. if thats the only way i will sell it.. i know its a used lathe but the ways looks good but they do have some rise at the bridge.. i will check that first when i get to the shop next time.

i dont need a tailstock that i need to adjust all the time..

Originally Posted by Demon73

It would be nice to know how the op leveled the machine, Ie which surfaces. If it was saddle flat to tailstock flat could double check riding the carriage and across the V tops (after checking them).
At a glance the ways look in great shape, turning .006" in 6" id expect them to be trashed. Looks like theres an area on the saddle V way thats not getting hit, could sweep those ridges for an idea of wear.


I dont like how the bar was clocked, be nice to have the indicator where the tool would be so you know what the tool sees.


IF:-
The ways are in good shape.
The bed is level.
The saddle isnt jacking off the gap or something else silly.
And the headstock turns out to be adjustable (which im thinking it likely is).

Its pretty obvious the headstock just needs a nudge over. Im sure no pro would torque the bed in that situation.

Tom chases his tail for a bit before bumping the HS.

i checked in the flat way with my precision level and ontop of the saddle all the way down the ways every 100mm aprox.. there where very little flex( not over 0.02/m).

i tryed to see if i had a lose saddle/cross slide or anything.. nothing i cound find.. i do have abit to much backlash i the cross slide but i doubt thats the problem.