A few weeks ago, I was reading about machineing and I read that the longitudal axis of the tail stock of a lathe is .006" above center line of the head stock. The way the writer talked, this was common to all lathes.

Does anyone who has experience with a lathe know anything about this? I don't remember where I read it.

Seems like this could mess up a chambering job.

You could sweep the tail stock I.D. with a coaxial indicator from the chuck and see if it is out of concentricity with the chuck. I would indicate in the flutes of the reamer in if its an adjustable reamer holder, or let the reamer find its own centerline if it�s a non adjustable floating reamer holder with the I.D. of the barrel.

Mike

Never heard of a tail stock being 0.006" above the bore of the headstock, more like 0.001". That is to account for wear of the lathe bed as well as the weight a center or chuck deflecting the tailstock.

You know, if your chambering method is solid, the tailstock has no bearing. To eliminate tailstock misalignment, I only use it to push the reamer. I do not use a floating reamer holder.
Butch

I wrote messing up a chambering job, but I meant anything that needed to be held between centers, or drilling with the drill held in the tail stock.

If the tailstock was .006" high, wouldn't everything you turned be tapered, or everything you drilled be slightly off center?

Will the pilot on a reamer start it straight and keep it straight, if you do not use a floating reamer holder?

When chambering, reaming or drilling, the axis of the tail stock has to be aligned with the axis of the headstock spindle. The further off axis the alignment, the worse the results. Period. A good floating reamer holder will help close the distance, within reason. As for floating reamer holders, the PT&G "Bald Eagle" is probably the best one out there.

It does little good to spend all day dialing in the bore in the headstock if the tailstock spindle isn't aligned with the headstock. Think about it.

I probably spent nearly a half day just adjusting/aligning the tailstock to be as close to perfect as I could measure, the day after it was delivered..

I check it often to ensure nothing's moved..