current settings for maestro

mystix

Question about the Duet maestro,

I have a M3D Crane Quadfusion. It uses a Duet Maestro. In various groups we are working on dialing in our printers and figuring out the ins and outs, but the documentation varies. So I thought I would come here to the source for an answer that has been plaguing us for a while, with different answers appearing in different places.

In dialing in the motors with m906 you specify the current in ma. Question is what is a valid amount.

https://duet3d.dozuki.com/Wiki/Gcode#Section_M906_Set_motor_currents
Indicates steps of 100 ma which are rounded down. (but maestro not specified)

https://forum.duet3d.com/topic/10196/ender-3-pro-configuration/26
comment here by dc42 indicates:
" Stepper motor current is adjustable in steps of 100mA on the Duet WiFi/Ethernet, and 50mA on the Duet Maestro. "

This would seemingly be the end of the question here. BUT for a few things.

It would be great to see this somewhere in Maestro documentation.
Someone else has been told by M3d support that 40ma is the minimum increment they should use.
Firmware for the M3d Crane Quadfusion comes with a default of 480 on the extruders. (smaller motors than the others) Note that 480 is not divisible by 100, 50, or 40. So that could either indicate a smaller increment, or that it is just placed there for some readon to get rounded. (Why would you set it up that way?)

What say you?

dc42

The increment on the Maestro is 50mA. 480mA will get rounded down to 450mA, it's only values that are very close to 500mA that will get rounded up to 500.

mystix

@dc42 said in current settings for maestro:

The increment on the Maestro is 50mA. 480mA will get rounded down to 450mA, it's only values that are very close to 500mA that will get rounded up to 500.

Thenk you very much for the information. We've been trying to nail down some more solid documentation for our new printers so its good to have it here nice and concise.

ObiJohn

@dc42 I was wondering is it possible to get finer adjustments in current. Part of the issue with a 4 into 1 nozzle is the 4 motors need to be balanced. If the balance is not correct you get unpredictable extrusion. The better the control over the current the more accurate the extrusion balance