Newbie migrating a gantry from Mach3 to LinuxCNC

andypugh wrote:

See what happens if you run the machine without the motors / drives connected. LinuxCNC won't notice the lack.

I noticed that, and thought it was a little curious - being used to Mach3 locking itself in E-Stop mode whenever the G540 is powered off (or, obviously, when the hardware e-stop is punched). Then I realized Mach3 was set up, back in the foggy mists of antiquity, to read the G540's fault/estop signal on pin 15, and apparently LCNC's stock Gecko configs don't pay attention to that.

I think I've got a lead on how to get all the pieces communicating again (via a thread that's heroically been soldiering on since 2013), but it's going to have to wait until the vacuum cleaner (and/or elephants - not entirely sure which) running back and forth overhead & rattling my brains loose stops long enough to let me think it through & try it out.


-Bats

Great you have movement.

When you install your limit switches, just be aware that they must stay triggered from the home switch trigger point right through to the end of travel in one direction. I learnt this in a fairly brutal way!

So when homing if the home switches are enabled, LinuxCNC knows which way it must travel to disable them and then it approaches the home switch again to commence the homing sequence.

Rather than deal with all this on my router i connected both steppers to one terminal on my breakout board.

This has worked for years now, very reliably. I checked that the breakout board optos could handle the current of two drivers.

As far as homing goes, I have mechanical stops on the gantry rails. On the rare occasion that the gantry goes out of square, usually after a collision of some sort, I jog it into the stops and it squares up. The leading motor just skips steps until the lagging one catches up. Then they both skip and you stop jogging and then I manually home it on the Axis screen.

I also home the X axis this way. Hit the stop, hit the home button. It's very repeatable if you use the same jog speed.

Why am i here? I'm rebuilding a machine with a G540 and I can't easily do my little shared output trick. So I'm trying to do it the right way.

I'm taking my airgapped PC to the internet to run an update as my current version does not honor the Stepconf XYZ setup that routes the same signals to multiple pins.

Also to install NativeCAM, which makes LinuxCNC even better than it already is.