bed is twisted, or the floor is, or I am

Two-collar test on the 9A, ten inches between collars. Headstock end collar is 0.0015 bigger at the back than the front. Tailstock end is the opposite by about a thou. I shimmed one foot and made it worse. Wood floor. I know. I've read the level thread. I'm still lost in my own shims.

You have twist. The collars telling opposite stories is the picture. Shim the foot that reduces the difference, then cut the test again. Do not stack shims until the story changes sign and then add 'just one more.' One change, one cut.

And get off the wood if you ever can. You can level a lathe on a wood floor every season and the floor will move anyway. I have said this. I will say it until the floor apologizes.

Gus is right about the floor and wrong that saying it again fixes this Saturday. Delaney, one shim, the thin one, the low back foot if the headstock collar is fat at the rear. Cut. Write the numbers down. The ones in your head are how you made it worse.

Pulled the stack off. One thin shim under the back headstock foot. Collars now disagree by less than half a thou, same direction, which Piotr's note says is alignment and not twist. I'll take the half. The floor remains unapologetic.