My tailstock is out of alignment

[tmuir]

I noticed last night when drilling my tailstock was slightly out of alignment and checking it today is seams to be out of alignment but atleast 1mm.

I'm going to try and adjust the tailstock tonight but I have no idea how it has got out of alignment.
I have checked the ways and the underside of the tailstock and they are all ok and free of chips.

I'm confused as to what has happened as nothing seems loose anywhere to allow that much movement.

 

[rickharris]

Not wanting to hijack your post but I have a relevant question I have read some ways to check and align your TS - is the following a practical approach:

Fit a dead centre to tail stock and one to chuck. Align the points vertically and horizontally a small steel rule trapped between the points should give a good visual indication of how close to vertical and horizontal alignment you are. From there more accurate alignment can be done by comparing a dial indicator reading on both dead centres.

I ask because I am too scared to move my tail stock to try realigning it. I have checked by turning a bar and checking for taper so far ot looks OK in so far as a cheap Chinese lathe is OK.

 

[Kermit]

My tailstock is also off, only I don't notice it working at the chuck end since my lathe has about 28 inches of length!

I'll give your suggestion a try rickharris.



Kermit

 

[tmuir]

Fit a dead centre to tail stock and one to chuck. Align the points vertically and horizontally a small steel rule trapped between the points should give a good visual indication of how close to vertical and horizontal alignment you are. From there more accurate alignment can be done by comparing a dial indicator reading on both dead centres.

Thats exactly what I just did.
I took photos but left the camera in the workshop :
One thing I will say about the alignment screws on my Chinese tailstock is they are pretty much useless.
It looks more like they aligned it up pretty good and then just wacked the top home in the base so loosening one screw and trying to tighten up the other does nothing.

I've got it good enough for now but will need to revisit it. To adjust mine I had to take it off the lathe, loosen all the screws, prize the top up slightly with a screwdriver and whilst having the top half rest on a block of wood wack the lower half with a rubber mallet. Four or five times doing this with 3 or 4 blows each time and then rechecking on the lathe has shifted it a fraction of a mm.

I guess we can't expect too much from a cheap Chinese lathe.

 

[tmuir]

Not the clearest of pictures but the top image is what it was like when I started and the bottom image is where it is at at the moment.

I will need to revisit this again.

 

[Kermit]

Are those pictures side view or from the top looking down?
I think my lathe is out in both directions.

My vertical mis-alignment should be correctable by inserting the shims under the front end of the bed(under the chuck end) to bring it up and the tailstock down in relation/

Is that correct?

 

[tmuir]

That is the view looking down.
The chuck is pointing towards the front of the lathe.
As standard all Chinese made lathes have the tail stock a little high.
I'm not an expert in shimming but I think its the headstock rather than lathe bed that would need to be shimmed and thats not something I'm ready to try yet.
I can't even get the silly adjusting screws in my tailstock to work correctly so I'm staying away from the headstock. :big:

 

[Kermit]

My tailstock is not AS stuck as yours. Perhaps Robert@lathemaster unsticks them before we get them? But it was not a simple thing to make it move. Deburring and some good metallic copper anti-seize went on it as well. I think the repeated tightening of the tail stock over time re-welds it onto the moveable base. So I'm trying the anti-seize to see what if anything it can do about that.

Figured I'm in whole hog, so I just took the tailstock apart and worked it over and put it back at least as bad as before. Maybe better maybe worse, but its still just a small amount objectively speaking of course.

I have three DI on mag bases now, so I should be able to do this.

Got off work early to align my lathe? ???
Is there really some wrong with me?

 

[rake60]

Tailstock misalignment can be caused my many things.
A slight wreck, over tightening the center, temperature
changes, humidity variations or maybe even the phase
of the moon. scratch.gif

Even the highest precision CNC turning centers will display
tailstock alignment variations from day to day, and somtimes
hour to hour in widely swinging temperatures.
It is not uncommon by any means. You adjust it and go from
there. It's not a machine flaw, just a fact of life for operating
a lathe.

I remember complaining about having to adjust the tailstock on
a tired old lathe for the third day in a row when I was
just beginning to train in as a machinist. The cranky old buzzard
who was saddled with training me openly expressed his thoughts.
"Kid, a machinist is a mechanic who has the skills to actually
operate the machines he maintains."

That comment made an impression on me...

Rick