8A Pump on Heated Bed Port [SOLVED]
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I'm interested in connecting a 24V, 8A pump to the Duet2. I see that the Heated Bed can handle up to 18A, but I am not sure how to set the PWM out for the Heated Bed Port (H0) so that the amperage flowing through it is appropriate.
We were looking at using M453 to us CNC Mode, but what is the Pin for the heated bed?
What we would really like to do is just vary the PWM ourselves, and bypass the PID control. Is there a way to do this?
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The bed heater is Heater 0, so after sending M140 H-1 and M307 H0 A-1 C-1 D-1 you can address the bed heater output as logical pin 0 in the M42 command.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
This worked great. Thank you!
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@dc42, I am having trouble with the pump connected through the heater now. Please see https://forum.duet3d.com/topic/5860/pump-connected-to-heated-bed-sometimes-won-t-turn-on. Thank you!
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Did you connect a flyback diode in parallel with the pump? It almost certainly needs one.
Duet WiFi hardware designer and firmware engineer
Please do not ask me for Duet support via PM or email, use the forum
http://www.escher3d.com, https://miscsolutions.wordpress.com -
@dc42 We implemented a stepdown from our PSU to the Pump, which has a built in flyback diode.
We believe the issue is insufficient wattage coming out of our PSU. From our previous model to this we dropped the PSU W out by 30%. We will buy higher W PSU and try again. Thanks for responding.
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This was an issue with the pump pulling against dead head and not getting enough momentum to turn over properly. Opening the solenoid to allow flow on pump startup solved the issue. Not related to duet.
