toolboard part cooling fan wiring

nick9one1

I seem to have an issue with my part cooling fan. Its a 12v radial. It will only come on at 100%. At 99% it doesn't turn.

Its wired black to gnd and red to out2 (no tach), the same as this;

M950 F0 C"121.out2" Q500                        
M106 P0 S0 H-1                                   
M950 F1 C"121.out1" Q500                 
M106 P1 S1 H1 T45

dc42

@nick9one1 many 2- and 3-wire radial fans don't work well with PWM. Some do if you use a much lower PWM frequency. So try a much lower Q value in the M950 command, for example Q80.

Phaedrux

You might also want to try adding B1 to your M106 line which will blip the fan at 100% power at startup to overcome inertia. That may be enough.

nick9one1

@phaedrux @dc42

Thanks for the suggestions.

I've done both and still only works at 100%

M950 F0 C"121.out2" Q80                       
M106 P0 S0 H-1 B1

this works and sets the fan spinning at 100%

M106 P0 S255

and while the fan is spinning if I send

M106 P0 S254

it stops

dc42

@nick9one1 you could try a Q value even lower than 80, but basically you have a fan that doesn't work with PWM.

nick9one1

@dc42

thanks. I just read the same in the gcode wiki

Qnn PWM frequency in Hz. Valid range: 0-65535, default: 500. (optional)

A value between 0 and 8 kind of works, but the fan seems to pulse and not really push any air. Anything above 10 and the fan doesn't spin at all.

I have a bunch of other fans but they're all 24v

Looks like I need to order a new one!

dc42

@nick9one1 there is a way to use 24V fans with the tool board, but then both fans must be 24V.

nick9one1

@dc42

That would work. the other fan is 12v as well, but I can easily swap it to a 24v.

nick9one1

@dc42

Is this the correct way to do it?

dc42

@nick9one1 yes that's correct. The tool board is designed to tolerate that connection. Both OUT1 and OUT2 will get VIN voltage.