Stepper current ratings (1A max for the LDO) vs M907 current ratings; are they RMS or peak?
 
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Stepper current ratings (1A max for the LDO) vs M907 current ratings; are they RMS or peak?  

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Slablaadje
(@slablaadje)
Active Member
Stepper current ratings (1A max for the LDO) vs M907 current ratings; are they RMS or peak?

I am looking into new steppers and noticed that the default current for X is 300mA and Y is 370mA, based on the settings in the firmware you can determine this. (it is value 16 for X which corresponds to 300mA in the conversion table in the firmware)

As the LDO's are rated for 1A and a lot of steppers are even beyond 1A, and are even underperforming when going below 50% of recommended/rated current (trinamic states this in their QSH4218 datasheet; the torque delivered is too close to detent torque and hence smoothness is reduced). I would like to use the QSH4218 but if they are not getting enough current to perform well it's kind of a waste of money.

I can supply sources on all my findings but perhaps someone who kind of knows about the situation can just answer the question that keeps me busy:

Is M907 settings peak or RMS? Is the 300mA for the X axis peak or RMS current? And how is it that 1A steppers are only getting 300-370mA? You can raise it with M907 but only a bit until you are forced to go info stealth mode; otherwise you will cause crash detection to go off as the regular current is already considered a spike and the crash detection is set off immediately. (And I don't plan to recompile the firmware for it.)

Thanks!

Napsal : 09/10/2023 10:17 am
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