amps for steppers

hotrodford

I have and bondtech ddx extruder and it need 0.7 amps just want to make sure
I adjusted it right.
"Due to the fact that the DDX uses a 3:1 gearing ratio and includes a stepper motor that is rated to run at 0.7A, nearly half of the current stock "

M906 X800 Y800 Z800 E700 I30

Also when the print ends it backs the filament all the way out. how can I adjust that?

Thanks

jay_s_uk

if the maximum current is 700ma, you should be setting a value that is roughly 85% of that value. i.e. 595ma (which i think will get rounded up to 600ma)

Veti

@hotrodford said in amps for steppers:

Also when the print ends it backs the filament all the way out. how can I adjust that?

that would be configured in the slicer normally.

Phaedrux

@hotrodford said in amps for steppers:

Also when the print ends it backs the filament all the way out. how can I adjust that?

Change your slicer to use relative extruder moves instead of absolute extrusion.

fma

Sorry to hijack this thread, but it is correlated : what is max current given in motors datasheets? RMS or peak? And so, what does 85% represent?

jay_s_uk

@fma 85% of peak

fma

To be sure to understand: I have to set the RMS current of the driver to be 85% of peak current of the motor?
And the motors datasheets give peak current per phase?

Dougal1957

@fma that depends on the motor manufacturer for example OMC afaik use peak but LDO use RMS.

fma

Ok, thanks!