Before I embarked on calibration of the axis, I needed to get the column square and trammed. I couldn't just tram the column to get it square to the table. The rotating head queered that. Instead I mounted a 1-2-3 block on the table. I mounted a .0001 resolution dial indicator to the head so that it bore on the block. I then ran the head up and down whilst tapping the column into alignment. I managed to get it down to .00015 in 2.5", or .0006 over 6". I have no way to check the accuracy of the block, it is probably good enough for anything I would make. I then mounted my tramming device in the head and adjusted the rotation so that the spindle is square to the table.
I had intended to invite Ray over and have some fun calibrating the steppers, but I discovered that I really didn't know how to do the calibration. The original hacked up machine was run with Mach3. Once that machine had passed the smoke test and hadn't fallen apart after a few hours of running, I needed to make a decision on legal software to run it. Mach3 is nice, but I still don't think the few times I will probably make things with it justify the cost. The version 1 machine finished life running with linuxCNC. The ancient PC that I am running the machine with also likes Ubuntu better than the recent versions of windows. So, the ini file to run linuxCNC was converted from the original Mach3 one. That method didn't work now that I had different screws moving the axis. After some experimenting I found the ini parameters that needed to be changed. Only when I was about done with the calibration did I figure out how to use the built in calibration routines. The axis are now accurate to about .0003. I still need to check backlash, but I am putting that of until I solve the next ugly problem.
While messing about looking for documentation for the HAL parameters, I discovered that my version of linuxCNC is 2.5 and no longer supported. The current version is 2.7.7, but you can't upgrade to it unless you do an upgrade to 2.6 first. I don't have networking on the controller PC. Upgrading once is a pain, but upgading twice to get to the current version is not going to happen. I saved all of my custom HAL settings. I downloaded the latest version of linuxCNC and burned it to DVD. Tomorrow I will receive a wifi dongle that is supposed to work with ubuntu. tomorrow afternoon I will lock myself in the shop and reinstall linuxCNC. Worst that could happen is that I have to retreat to 2.5. If I'm really lucky and hold my tongue to the roof of my mouth, while tapping my left foot and singling Dixie, I may end up with version 2.77 and wifi access.