Huxley Duo - Cooling fan - NOT hothead fan

Hi All,

I have a Huxley Duo (Xmas Pressy).

I have managed to get it all working except the cooling fan.

Is there an easy way to test these fans (battery?) as I have checked the wiring (all appears OK).

I have also used the web interface to try to turn this fan on and off (M106 S255 - on M106 S0 - off).
A led lights on the Duet PCB and 19V appears on the connector. This also appears at the connector at the other end of the harness, I cannot easily check on the FAN as the pins are VERY close together.

Other than this issue I cannot fault this Huxley, it prints fine (as long as I dont need the fan)

Any advice please.

JMK

You can try to supply from a laptop adapter. However, you'll need 2 wires and pay attention to prevent a short. Also, you may need 4 hands

Did you try reversing the connector?

Hi,

yes I have tried to reverse the pins, Will these fans work on pure DC or do they need PCM?

JMK

Well All,

I have checked out the fan on 19V dc and there is no life in it at all - looks like i need to order a new one.

Thanks for the advice.

JMK

Hi,
I also got a Huxley Duo as an xmas pressy and have exactly the same issue. The fan is OK - swapped connections with the extruder fan. Would like to get it going as the last print I did was a bit soft and seemed as though it could benefit from more cooling to "harden" it up a bit quicker.

As you say other than the fan issue it seems superb for the money. Its accuracy is good at 0.2mm layers - the lego brick I printed actually "clicked" into a real brick.

Roger

Hi,
Sussed the problem. The black wire had a bad crimp - well the copper cores were broken through - the back of the crimp was just holding on the insulation. When I remade it (soldered the wire) I found the copper cores break VERY easily. I think when I tested it on the extruder fan supply I disturbed the connection to make it work. I would check continuity from the pin to the small PCB solder connection on the fan itself on both leads as I suspect this is a weak spot.

Hope this helps.

By the way the M106 command only seems to make the fan move with numbers greater than 235.

Roger

Sorry you're having problems with your fans. If you contact support on support@reprappro.com we'll replace any failed fans.

The quickest way to test the fan is to remove it from the printer, so the two ends of the wires to the fan are free, turn power on to the Duet, and touch the red wire to the positive 19V screw terminal (power in) on the Duet board, and the black wire to the other terminal (ground). If there's 19V going into the board, the fan should spin. If it doesn't spin, there's probably a broken connection in the fan. You can test the continuity with a multimeter between the crimp and the soldered connection on the back of the fan (in case it's just poorly crimped). If it does spin with 19V, check the continuity in the wiring loom - again, it may be a loose connection or poor quality crimp in the loom.

Regarding crimping; the fan wires are rather thin. We've found that you need a good pair of wire strippers, or it can damage the copper cores. And we have had a few problems with crimping; hopefully, all this is now sorted out from a production point of view.

For the cooling fan, it is not 'on' by default. To test it, you need to turn it on, and there's a specific Gcode to do this - M106 - [reprap.org]
Send M106 S255 to turn it on M106 S0 to turn it off.

I tested the fan speed control with a couple of fans; on the Huxley I have on my desk, both fans turn on at M106 S190. The fans do need a minimum voltage to turn, so this isn't entirely surprising. If it's much higher than this, it could be your fan is just a bit 'sticky'.

Control of the cooling fan is set in Slic3r, in Filament Settings > Cooling. It's generally worth just turning the cooling fan on 100%, once the first layer or two is done (when the fan should be off); there is little reason to run it at less than 100% for the rest of the print. If you have problems with warping, it may be worth turning it of if, for example, the layer takes longer than 1 minute to print, rather than forcing the cooling. It really depends on what you are printing...

Ian
RepRapPro tech support