Starting over

On a side note, so it does not continue to miss inform the public, G540 has NO micro stepping, it Has a delay (most probably a CD4017 CMOS), so it does nothing for 9 pulses. NOTHING. Wasted 2 days a while ago to figure that out.
They do mention that on the web, so it's all good, and they are perfect for hobby machines.

tommylight wrote: On a side note, so it does not continue to miss inform the public, G540 has NO micro stepping, it Has a delay (most probably a CD4017 CMOS), so it does nothing for 9 pulses. NOTHING. Wasted 2 days a while ago to figure that out.
They do mention that on the web, so it's all good, and they are perfect for hobby machines.

Joy - smoke and mirrors.

I've noticed mine gets too hot too fast. Since I've not put this into production it's set idle under a strong fan most of the time.while I am tweaking Linuxcnc. I can't imagine what it would do if it were running hard. I thermal pasted the driver's chips to the back of the case - helped some but when it gets a little warm one port acts up.

If Gecko can't fix it under warranty I may go with another brand.

Did you wire the resistors on the motor connectors? You should, as without them it will run on full power even at a stand still. They need a 1kOhm per 1Amp of current, and even if you need full power, do add some 3.3Kohm to it.
I had 2 of them, still working without any issue, and never got to hot to act up, with no cooler or fan.
At what voltage are you powering it? I never used more than 32V for them on everyday use machines.

tommylight wrote: Did you wire the resistors on the motor connectors? You should, as without them it will run on full power even at a stand still. They need a 1kOhm per 1Amp of current, and even if you need full power, do add some 3.3Kohm to it.
I had 2 of them, still working without any issue, and never got to hot to act up, with no cooler or fan.
At what voltage are you powering it? I never used more than 32V for them on everyday use machines.

I did - I bought a 4 motor kit with cables featuring 3.5k resistor between pins 1 and 5 on the Gecko end and a 48V 12.5A switching power supply running 420 oz-in motors. I tested the cables when I got them.

Patrick Obrien wrote: Please correct me! My logic is the rack (20 pitch 20 degree pressure angle) has 20 teeth on a one inch pinion.

No, that is correct. a 20-tooth 20DP gear is pi inches per rev.

Update: I have been fighting the G540 for a while and realized it was a large part of my problem. It might have been just my own G540 but even in light duty build/test-mode that device is designed to get hot and heat makes it flaky, even with a serious fan blasting the high heat area.

The steppers were baking at idle, etc. Gecko suggests you use a heat-sink but all the MOSFETs don't touch the case and would not benefit from a heat-sink.

I installed four ST-M5045 and it is a huge improvement. The idle steppers are cool to the touch (utilizing the optional 1/2 hold power) and the drivers don't seem to be above room temperature probably because someone had a clue and designed heat-sinks into the design.

The G540 is $300 and if you lose an integral axis replacing that one G540 module is $80 but for $80 I can buy two standalone ST-M5045's.

No regrets.