Tramming the Tormach PCNC1100

[@steveh8724]

Thanks very much for posting this!! You and your assistant did an excellent job of demonstrating the method of measuring alignment errors and the simplest approach to minimizing them. I'm about to uncrate and assemble a Tormach 1100M and will be starting adjustment with the checks you've shown. It was great that you also briefly reviewed the construction of the holder for the two dial indicators. I've watched several videos showing the use of similar devices (including both DIY and commercial products), but it was only in yours that it was made clear that the mounting bar itself doesn't need to meet any exacting specifications *since the indicators are adjusted to zero anyway.* If I had realized that, I might have gone the DIY route instead of purchasing a commercial product. Oh well, I would have had to purchase the dial indicators anyway. As to terminology, I think the other comment is correct. What is illustrated is not true tramming, it is just removing/adjusting "twist" in a manner that produced the desired geometry at this particular spindle height. The Tormach 1100 manual does describe other methods that more directly approximate tramming but these may not be necessary depending on the desired precision and the state of the particular mill. So there is no 'should' about further work, it's more 'could'. And since this mill design does not incorporate the adjustments that a Bridgeport manual mill does or more expensive CNC mills do, it is not even possible to fully tram a Tormach 1100 in the conventional sense. Finally, 'leveling' is clearly a somewhat misleading term when it comes to mills and lathes. What is described as 'leveling' has nothing specifically to do with being dead flat level relative to the earth. It has to do with removing twist. This is easiest to understand in the case of a lathe where one can evaluate (using a very sensitive level) the consistency of 'levelness' along the length of the ways in conjunction with looking at the degree of taper cut along a turned cylinder. Looking at changes in 'levelness' along the lathe bed helps in interpreting the degree of taper cut on a cylinder that ideally would have no taper at all. So there's no requirement that a properly adjusted lathe is also perfectly level in the conventional sense of the word. Lathes work on battleships for example. And they're floating on moving water.

[@williamclark77]

I did the DIY route because 1) I had the scrap on hand 2) I'm cheap and 3) I made the length to fit the bed without ending up between slots. And yes, leveling to earth doesn't work as expected. Mine is not level like that. I tried using a precision Starrett level but still had excessive "tram" run out. So yep, I'm basically twisting the bed square. The cut results after "tramming" like this were noticeable and less chatter since I was able to tighten the gibbs more without binding or adding lost motion anywhere along x or y. I need to redo it soon. The adjustment bolts I added to the table feet have loosened over the past year. I haven't had a chance to stop and do it. It's one of those things that may take five minutes to get right or take up half a day chasing your tail.

[@cssetzer]

I think you are just twisting your base, not actually tramming as you should.

[@shirothehero0609]

Agree, All these videos are doing the same thing - adjusting the base, not the tram of the head.