Layer Fan regulation in DC42 Duet Firmware

Hi all,

I´m quit new to the Duet and I´m installed a Layer Fan to my Kossel (first time due to only used ABS)

I can´t get it work. Is M106 not the right command at the dc42-fork?

M106 P1 S1 set the Fan to off.
M106 P1 S0 set it on.

but what about regulation? 50%, 75%?

And how to tell S3D to use specific commands for this?

Can anybody help me out?

thanx
Dirk

You can pass an S parameter to M106 either in the range 0 to 255, or in the range 0 to 1. So M106 S0.5 or M106 S128 in theory give you 50%. In practice, most DC fans do not work well with the whole supply being PWM'd, so you are more likely to need M106 P0.85 or M106 P200.

A 4-wire PWM-controllable fan gives much better speed control, but it needs a bit more electronics to make it work with the Duet (or other electronics). I hope the next revision of the Duet will have support for 4-wire fans built in.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanx David.

Fan is the same as I used with my E3DV6 and the smoothieboard. Working with PWM there.

What I dont understand is, that M106 P1 S1 set the Fan to off. While M106 P1 S0 to on. So its vice versa. S0 is 100% and S1 is off??
Hm, currently I have a print running (which is absolutly fantastic with the Duet and the IR-probe!!). But when it´s finished I will check if I can figure it out...

Thanx again

cheers

Quote
critical_limit
What I dont understand is, that M106 P1 S1 set the Fan to off. While M106 P1 S0 to on. So its vice versa. S0 is 100% and S1 is off??
Hm, currently I have a print running (which is absolutly fantastic with the Duet and the IR-probe!!). But when it´s finished I will check if I can figure it out...

I guess you are using a Duet 0.8.5 board. Send M106 P1 I1 to invert it. You can put this in config.g. In my next firmware release, I will invert it automatically when a Duet 0.8.5 is detected.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

aah!

That did the job! Perfect!

Thank you very much!

ok, now I can switch the fan on and off with M106 S0 or M106 S255.

But M106 S254 stops the fan.
On the smoothie the same fan is working and can be pwm controlled. Is it a question of the frequency? Can I change pwm frequency on the duet as i can on the smoothie?

The fan PWM frequency is set to 25kHz because that is the frequency needed when driving a 4-wire PWM fan made to the Intel specification. I don't know whether a lower PWM frequency would work better. Currently the PWM frequency is not configurable in RepRapFirmware, but I may change that in a future release. The core work on variable PWM frequency is already done in the release I am currently preparing.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

thanx David. I will check Github now every day... ;-)