Lathe Issues

[PestShooter]

When I turn bar stock on my lathe it is tapered even though I don't want it to be. If one end measures .050 then the other end will measure .040. Why does it do this?

 

[medicineman]

Your tailstock is out of line with the headstock. This is a common method of tapering barrels. Your tailstock is adjustable, there will be a set screw or some sort of screw adjustment on the base.

 

[PestShooter]

That is what you would think but I am not using the tail stock.

 

[BoydAllen]

Spindle CL out of line with ways?

 

[PestShooter]

Could be. How would I fix that?

 

[rayjay]

Deflection ?

 

[RMiller]

+1 on deflection if your really turning somthing only .05 in diameter.

 

[GerryM]

Your not specifing the set up.
Is it in a chuck? a collet ? Has it been set up with a dial or test indicator?
It could be Many things. Even worn ways .

 

[PestShooter]

I did not set the lathe up when I got it. It is a Logan 200. I am using a 4 jaw chuck and I dial indicate the work so that there is zero runout. I was turning steel bar stock. I took a few cuts only taking off .005 of material. The end farthest from the chuck was .651 in diamiter. The end of the cut closest to the chuck was .646.

 

[Brodie]

If you have a machinists level, check to see if the lathe has been levelled. This might be caused as others have said by the ways being distorted. If it is level already then you may have to unlevel it (as strange as that sounds) to get it making a cut without taper.

 

[GerryM]

You can also use a set up bar between centers

Run a dial indicator in the carriage {tool post] and check run out by travelling back and forth . If the ways are worn it will show up on the dial.

 

[PestShooter]

I leveled the lathe and I cuts just fine now. Thanx guys.

 

[Bert]

The rule of thumb for a lathe is the work piece shouldnt stick out of the chuck more than 5 times the dia. unsupported.

 

[GerryM]

Glad your squared away'
Logan is a good lathe.