Topics created by thomas.weiss

@thomas-weiss something else to check is there are no speed limit setting commands in the job file from your CAM processor.

You can send M203 from the command line in DWC to confirm the setting, then try moves from one end of your longest axis to the other with F4000 and F6000, sending them directly from the console. e.g.

G1 X0 ;start at 0 G1 X150 F4000 G1 X0 F4000 G1 X150 F6000 G1 X0 F6000

@thomas-weiss that's correct, the motors no longer default to stealthChop. The reason is that stealthChop doesn't work well unless you execute the proper tuning movement during homing.

@jay_s_uk I see - you are right. Echo to file was added in 3.4, an update should solve this. Thank you!

Sadly, we'll need our prototype for a presentation in the upcoming days and I don't want to risk that a firmware update changes or breaks any functionality that we already implemented.

Might have to go without this function for now.

@thomas-weiss said in M915 not triggering under any circumstances:

Alright. I just did some testing. Setting M569 to V20-V50 makes it trigger stalls, but the motors seem to be incredibly weak and loud even at 2200 mA current. They are basically just stalling themselves in an aircut without doing any actual milling.

I'm not really surprised. When the driver run in stealthChop mode, it switches to voltage-controlled mode, so that the current is reduced and the motors are quieter. The ability of the motor to respond to large increases in load is compromised. For example, when 3D printing if the nozzle hits a blob or overhang, missed steps are more likely if the driver is operating in steathChop mode.

In a milling machine the difference in load between homing (when the tuning cycle is done) and milling is much greater than the load change in a 3D printer. So I am not surprised that stealthChop mode doesn't work well for milling.

Additionally, stall detection doesn't work well at low motor speeds, because the back emf due to rotation isn't high enough to distinguish reliably from the other voltage drops in the motor.

Drivers that do stall detection in spreadCycle mode (such as the TMC2660 on the Duet 2, or the TMC5160 on Duet 3 MB6HC) may be more suitable for stall detection in a milling machine; however the low motor speed might still make it unreliable.

@thomas-weiss do you mean the Laser/VFD port? Yes you can connect it directly to that port; however it has a 100 ohm series resistor plus the internal resistance in the buffer, so you might not get quite enough voltage and current if the laser needs 20mA.