G540 and slaving

[KTP]

Do you forsee any big problems with using the G540 to slave two x axis steppers together for a small gantry system? I have never actually tried to do that with steppers (or servos) so might be missing some aspect that makes it difficult.

I want to make a little compact gantry out of a bunch of thk KR series ballscrew actuators and the simplest bolt together solution would be to use two for the x axis, one on each side, both driven.

Since the G540 is 4 axis, this seems a simple elegant solution.

[CNCDevil]

No problem at all. You can slave one axis to another in the control software, e.g. if you use Mach3.

[crash5050]

Would you happen to have a Hoe-To for that in Mach3? I have tried everything I know to do to get my 540 to salve a to x.

[CNCDevil]

It is very simple. Just sellect "Slave Axis" from the config menu. In the left X-axis coloumn you just mark the A-axis as the slaved axis.

All signals sent to the X-driver are now also directed to the A-driver. Remember to restart the program.

[Pandinus]

^^^^^^^^^^^^^

AND be very careful when you first try to move your slaved axis...
if one motor moves north and the other south things might break, don't ask how I know.... and I thought I was being careful.

You can reverse the slaved axis in the Config>Homing/Limits... or reverse a phase of your stepper.

[crash5050]

I have done exactly what you said to do, set the A to be a slave of the x, no joy. I have restarted the program, three times.

[CNCDevil]

What are the motor pin-outs for all the axis´ set to?

[crash5050]

Well, I finally figured out what the problem is. The 4th Axix stepper driver in my Gecko is bad. I took the X and A axis boards and swapped them out, restarted mach3 and guess what happened? The A motor turned and the X did not. Just to be on the safe side, I tried a different motor on the X axis, no joy... So Gecko Folks, if you are watching, I need a new driver board!

Qualls

[blades]

I thought the G540 was nearly bulletproof.... good thing you tried this little exercise, else you could drive yourself crazy trying to figure out what's hooked up wrong (being a noob, i would assume it was something I did wrong). Sounds like it will be pretty easy to fix though.

[Mariss Freimanis]

Well, I guess that's the good thing about the way the G540 is built. It comes every bit as much of a surprise to me as it does to everyone else.

We had a customer that totally blew out the X axis drive. It smoked and caught on fire kind of blew out. The drive was totally toast. It stank big time and so did the G540. We removed the X axis drive and plugged the G540 in. Nothing was expected from it because the damage was so extensive.

It ran. It ran flawlessly (on 3 axis). It surprised me and our technicians.

We washed the boards (detergent and hot water), replaced the fuse (it had been subverted with a wire shunt) and placed it in an oven set to 100C to desiccate the parts. The G540 was replaced with a new X-axis drive. Washing was required because anytime there is a fire the residue is acidic and corrosive. It passed all new G540 tests on the test stand.

This was as nasty of a G540 failure as I have ever seen. It still ran without a problem once the dead X-axis drive was removed.

Mariss

[blades]

Holy crap! Gotta love that modular construction for serviceability.

[crash5050]

It suprised me also, Gecko can check it out when it gets there next week. I am sure that I did something, being the n00b that I am :P