Duet 3 6 HC with NEMA34, current low
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Hello,
we are using the Duet 3 6HC with Nema34 motors.
We set the current to 6000mAh mit M906 X6000 I90, but it seems like the used current is much lower, so we are not getting enough torque. The measured input power draw is around 24 V, 0,8 A.
What could be the reason for this?
Thank you.
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@operator you can check that 6000 is actually being set. Send M906 by itself. What's being output?
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@operator
Does the controller know where the X-axis is connected to?
The driver needs a direction setting at least
and in most cases a drive mapping -
@operator said in Duet 3 6 HC with NEMA34, current low:
We set the current to 6000mAh mit M906 X6000 I90, but it seems like the used current is much lower, so we are not getting enough torque. The measured input power draw is around 24 V, 0,8 A.
What could be the reason for this?That's normal. The motor doesn't need 24V when stationary or moving at low speed, it needs 2.4V @ 6A. The driver converts 24V @ 0.6A to 2.4V @ 6A. The actual draw per driver will be a little over 0.6A per driver because the efficiency is a little less than 100%.
When the motor is accelerating or driving a load, the current draw from 24V will be a little higher. When it is decelerating, the current draw will be lower.
Also note that the standstill current is limited to in the firmware to 4.5A, so the holding torque when stationary will be reduced by about 30%.
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@dc42 seems to be right. But we get a maximum peak current of 2,6 A at the drivers output, instead of 6A. What could be the reason for this?
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@operator the current may be reduced by the standstill current factor (when the motor has been stationary for a fraction of a second) and the idle current reduction factor (when all motors have been idle for the timeout period, default 30 seconds).
The standstill current factor is set and reported by M917. The idle current reduction factor is set by M906.
