[Peter Neill]

I know, I know - I should have taken pictures.

I thought I'd take some time today to check the fit/grip of my 3/4" collets in the 1100, as on a couple of recent jobs I've had some pullout, so wanted to make sure I had full contact and minimum runout. So armed with an old pot of Stuarts Micrometer Blue and a couple very straight lengths of 3/4" ground Silver Steel I blued the collets up, then checked for contact (needed some stoning on the edges) whilst also checking runout in different positions. Using various combinations of both collets in either position (2 grooves for the locating pin) and different 90deg rotations of both the 3/4" bars, I was still consistently getting around 0.005" runout in pretty much exactly the same spindle position (marked with a paint pen).

I dropped the bar and the collets out, wiped out the bore with some IPA, then shone a torch up into the spindle nose for a look.
What I found were 2 L-shaped/corner-shaped indentations on the taper, exactly opposite each other. One had a surrounding burr a little larger than the other, and this was exactly opposite to the point where I was getting the high reading on the DTI.

It's pretty obvious at some point that a rectangular or square bar has been forced into or tapped into the spindle nose taper - after it had been ground - and the corners of the bar have indented the taper. Definitely has not happened at any point since I've uncrated the machine and been using it, so I can only assume it was a cock-up by some hamfisted hand at the factory.
Yes, I know I should have taken pictures, but at the time I was more concerned with removing the high spots surrounding the indentations, which were obviously forcing the collet to skew over.

Anyway, I very carefully stoned these down, and now at least they don't contact the collet face anymore, and runout and collet contact is measurably improved, but still a little worse than the Tormach specs. I'm going to drop them a short e-mail tomorrow just to let them know. I'm not really blaming them for it, nothing they can do about it, or could have done short of sending a replacement spindle, and then there would always be a question of who did it & when, but it was a little irritating, so I'll just give them a heads up and maybe they can check a few others every now and then.

[beanbag]

IF you have guts, you can use the Tormach as a vertical lathe and run a turning tool up the spindle.