Duet 3 6HC & Mini 5+ & 2x part fans only one starts reliably

[Phaedrux]

With small fans like that it could come down to luck of the draw.

[blt3dp]

@Phaedrux

I just did some testing on the Voron 0.1 and it acts the same way still. Definitely no magnets interfering. I wouldn't think these fans would be the spec'd fans there if they wouldn't work. The only real difference in my setup there is that instead of their recommended control board, it's the Duet.

I also went back to my Delta, and moved the fans from Out 7 to Out 4 and it seemed to work. Though, it may be because I had been messing with them for a while. I'm going to power it off for a the night and see how it acts in the morning.

Any ideas why that would work, if it weren't just lucky timing with me playing around with them?

Edit: Just tried to start them again and one wouldn't start, bumped the frequency up to 15000 and they wouldn't start. Dropped it down to 10000 and they started. I'll power it off and try in the morning to see.

Edit Again: Just tried again and one wont start.

[dc42]

@blt3dp if you are using the facility to provide a full power blip to start the fans, and the blip is long enough to start the fans, then the frequency is not relevant to whether they will start or not.

[blt3dp]

@dc42 I just woke up and powered it on and tried to start the fans with M106 S255 and nothing, you can see them move slightly but it's like it's not enough to overcome friction to get them started. I tried boosting the blip up to 5.0 and still no go.

[infiniteloop]

@blt3dp said in Duet 3 6HC & Mini 5+ & 2x part fans only one starts reliably:

tried to start the fans with M106 S255

Using a multimeter, what voltage do you get after calling M106 S255? The reading should be near 24V.

[blt3dp]

@infiniteloop it measures at 24.2V

[infiniteloop]

@blt3dp said in Duet 3 6HC & Mini 5+ & 2x part fans only one starts reliably:

it measures at 24.2V

That's fine. So, either you wired the two fans in series, or the one which doesn't start is defective. At a PWM of 255 (S parameter of M106), the pin is constantly powered.

EDIT: There's another possibility: do you control the fans thermostatically? How are they set up (maybe with a thermistor) in your config.g?

[blt3dp]

@infiniteloop they’re definitely wired in parallel. I measured the voltage on both “legs” of the splitter. 24v definitely getting to both fans.

I don’t do any thermostatic control of those fans, they’re gcode controlled part cooling fans.

They’re both good, it’s random which one will start while the other doesn’t. Sometimes it flips between.

And if I give the non starter an manual push it kicks up and moves just fine.

[infiniteloop]

@blt3dp

They’re both good, it’s random which one will start while the other doesn’t. Sometimes it flips between. And if I give the non starter an manual push it kicks up and moves just fine.

Every fan I know turns happily by itself if fed with its nominal voltage. You can test that when you attach both fans (wired in parallel) to the PSU directly. If one of them still needs a push or starts slowly, there’s something wrong with the fans - else, they don’t get enough current from the board. In the latter case, I would appreciate a photo of the board with connector so I can see which wires go to what pins.

[blt3dp]

Just coming back around to this, I've found it's the fans spec'd for the v0, which are gdstime 3010. They're known to die after being exposed to the heat from the chamber % hotend.

https://github.com/VoronDesign/Voron-0/issues/121

I've swapped them out the the Winsinn fans suggested and they seem to be fine now.

bmgoncu created this issue in VoronDesign/Voron-0

open 30mm blower fans sensitive to the hotend heat and stops working #121