I have a Harrison T280 lathe I am retrofitting to LinuxCNC. This is a stepper driven machine, the original controls were previously retrofittect with MicroKinetics stuff and I'm re-retrofitting with LinuxCNC and Mesa 5i25 / 7i76 while keeping the MK stepper drives. I did a clean install of 2.6.3 from a USB drive image. I'm new to LinuxCNC and PnCConf and while I'm making progress getting things going I'm running into a few issues I haven't yet found answers to in the docs I've found so far. Many of the docs I've looked at are incomplete and haven't been updated in 2-3 years


Issues so far:

1. I can configure and test the X and Z axes in PnCConf and get the velocities and acceleration set to my initial liking. These don't seem to be carrying over properly to LinuxCNC as I'm getting jog and MDI speeds that seem to be well below what I set and tested in PnCConf.

2. In PnCConf, the pages for homing/backlash/comp on X and Z seem to be disabled so I'm not able to set anything there. The machine has + / - limits on each axis with no separate home switches. The docs I've found on homing setup are rather confusing (configuration confusing, not logic). I have figured it out for manual editing, but I still have some questions as what it seems to want to do isn't optimum.

3. After some fiddling I have the Hitachi VFD controlled spindle operating in the PnCConf open loop test. On issue I have found is that when running in reverse and stopping, LinuxCNC drops the direction line before the VFD has completed the decel ramp, causing the VFD to slam the lathe into forward for the duration of the decel, obviously not a desirable thing. I haven't been able to get the spindle to operate in LinuxCNC however, or figure out how to configure the encoder input properly.

4. The lathe has an 8 position unidirectional stepper driven tool turret with a home switch. I currently have the stepper drive wired to stepgen 2 (0=Z, 1=X). I've not found any docs so far that give me much of a starting point to figure out how to configure the tool turret. Perhaps someone has a similar turret and they can share example code / settings?

Thanks,

Pete C.