What's new
What's new

Shim up head stock?

Ronniet

Aluminum
Joined
Feb 21, 2011
Location
Amarillo Texas
After clean up and repainting & rewicking of my 11" I was truing up the tailstock to the headstock and I see that my headstock is LOWER than the TS.
I would have not thought this, I figure the ways and tailstock would have been worn and would be HIGHER.
Since the Headstock only has the one bolt at the rear and the 2 under the spindle, I can place shims
under these feet or would I have to place shim material down both sides front to rear to bring it to the hight of the tailstock?
Ron
Yes the ways were taped off when painted, later when assembled, any burrs were removed and the vee and flats were cleaned with the rubberized sanding blocks to remove any discoloration or films.
same was done to the head stock and tail stock machined areas, all were free of burrs , debires, rust , nothing but nice metal
showing.
Sorry for typing it wrong the first time, as that was the way one would have thought it would have been.
 
Last edited:
After clean up and repainting & rewicking of my 11" I was truing up the tailstock to the headstock and I see that my headstock is higher than the TS.
I would have not thought this, I figure the ways and tailstock would have been worn and would be lower.
Since the Headstock only has the one bolt at the rear and the 2 under the spindle,I can place shims
under these feet or would I have to place shim material down both sides front to rear?
Ron

Yes , that's how you would expect to find it ; Headstock higher than tailstock .
Tailstock slides back and forth , so it wears on the bottom .
You can shim between the shoe and the tailstock casting to raise it to center , but if you measure carefully you will find that the tailstock spindle is pointing down and toward the front .
How are you measuring this ?
 
Also make sure that some paint overspray or a run didn't find its way under the headstock or on the ways.
 
correction of first post!

Thanks to all who replied, please see my post after editing , I completely typed it backwards,from what it really is.
I believe Bill caught my mistake in wording correctly as he read it.
The way I have checked it is, with a Last word indicator in the Aloris Tool post, a precision ground 1.250 X 14" test bar but only using one small marked part of the bar to be absolutely correct.
and it is being swung between two newly ground dead centers in the head and tail stock.
The tail stock it .015 taller than the head.
Switched at birth?
Ron
My first check is to level with a machinist level.
When setting the lathe I leveled with the best level I had at the time which was not a machinist level.
It is on a concrete floor but the floor was uneven, so I made blocks of 2 X 6 Treated lumber to surround the housing and the front legs, then by making my own planed shims of treated dry lumber until I got it level in all directions and then bolting to the lumber.
So before shimming headstock I will have to secure a level and think about making metal pads for the feet, I just cant see 1000 pound + machine setting on 4 nuts screws to 5/8 thread.
There should be a better way?
 
Well I am completely confused as to what the problem is but let me add this. DO NOT shim the head stock. Make sure its mating surfaces are clean and bolt it down. Everything else on the lathe is shimmed, cut, or ground to match the head stock. It is the zero point on the lathe. If you mess with it you will be chasing the proverbial tail around the late.

Also using a level to set the lathe is a good first step, BUT the proof is in making a test cut using SBL' s procedure. It is two step process, level first then cut a test bar and fine adjust. See SBL literature for leveling a lathe and don't ship the last paragraph.

Ed S
 
Ron , if you are indicating from your tool post to a ground bar held between centers , a lot or most of what you are measuring can be attributed to bed wear . ( carriage going down toward headstock would make headstock end read high ) .
Try this : Bring tailstock center to headstock center , and compare , and most likely you'll find that tailstock is indeed lower . Use a 6" scale pinched between centers to start .
 
Ed S, the headstock is Lower than the tails stock by .015.
I said it wrong in my forst post as opposed to the tailstock always being lower,but have corrected everything I have typed wrongly.
Yes the Headstock is lower that the TS.
I have used this same ground test bar in the past on other lathes and as the case always was , and have always had to shim the TS.
But I never ran into this, and it has me thinking that the TS may have been lost at one time or swapped wrongly?
Could that be the case?
If So, I really dont want to mill the TS, would rather shim the head if that is possibe?
Ron
 
It is possible that the tail stock is not original. Your first bet would be to split the upper tail stock casting from its base. Check deburr and clean the two mating surfaces. If there is paint remove it. Put the tail stock back together. Clamp it to the bed using the pressure of the bedclamp to make sure both halves are mated tight. Recheck your hight. If you are still off DO NOT shim the headstock. This was fitted from the factory. You adding shims will just introduce another variable in any misalignment. Also you have the v way to contend with. A shim however thin will be a PIA to conform over this and may lead to problems down the road.
 
Halligan has it right - the tailstock is the variable in this equation. If it is low, it can be shimmed, if it is high, it can be machined. The headstock was fitted at the manufacturer and since it doesn't move, it is where it was designed to be. You need have the tailstock's centerline height correct, and also the tailstock has extend in line with the headstock's centerline. If the headstock is in its original factory position, and if the bed is level and not twisted, that leaves the tailstock as the one part that has to be adjusted.
 
My money's on the non-original tailstock. I recently swapped tailstocks between two apparently identical lathes, and ended up with one tailstock higher than the headstock. I swapped it straight back!

George
 
Somebody's already shimmed the tailstock, and they didn't have
the right size shims.

Take it apart, remove all the shims, and then check it.
 
Like I said, I had the entire lathe apart, every nut bolt, taper pin, gear etc... and re-wicked it and repainted it, there are no burrs or shims as yet, all machined surfaces were taped off and before re-assembly were cleaned and deburred.
But when truing to the TS the head was lower.
I am betting that its a swapped tailstock.
First I will try at re-leveling the entire lathe , and then if that does not do it , I will find a 6" bar to use closer to the head. if it still reads @ .015 low I will mill the top of the TS base by that much.??????
Ron.
 
the easiest and least confusing way to check is to turn a short piece of scrap to the exact diameter of your tailstock barrell - then you can indicate it directly by bringing the tailstock up next to your turned piece.

ps- it`s almost gauranteed to exibit the condition thermite mentioned - it is a South Bend after all..:)
 
Shimming the HS is not so uncommon. Even on quality lathes.
It doesn't make sense to start somewhere in the process of measuring a lathe. You have to start at the beginning and work your way up. And the beginning is the bed. Level, not twisted, straight. If you know nothing about that, you can measure the rest as you want. The result will only be crap!

To measure TS::HS-alignment, you can put a feeler indicator onto the chuck, adjust it that it reaches into the MT of the TS and rotate the chuck to see runout. Not the best method, but the simplest one requiring no further metrological tools. This does NOT measure where the TS points to. It should point upwards and towards front.

Nick
 








 
Back
Top