I do not have the answer, but I am interested too…
I am building a step-motor controller and I did not find a proper arduino+shield (multiple motors)…
The controller board of the printer caught my attention because it has 4 motor drivers on board.
Great…
Any help?
Hi,
i hope this link will help you
store.open-electronics.org/3D/3D_electronics
reprap.org/wiki/3Drag_controller
Hi Topbox,
Did you find out the maximum FAN power capability? I want to install a second fan…
Thanks
Flo
Hi,
as far as I can see on the mainboard (and is identic to information you can find here) the fan output is switched with the same transistor-type as the heater outputs.
So some mA for a second fan shouldn’t be a problem …
Regards Bernd
[quote=“Topbox”][quote=“flo_s”]Hi Topbox,
Did you find out the maximum FAN power capability? I want to install a second fan…
Thanks
Flo[/quote]
The Fan, Extruder and Heated bed are all controlled by a 50Amp FET so there is no problem with fitting extra fans.[/quote]
Wondering if it could handle a 1.5 ohms printing bed on 13.8v without heatsink? Something like about 10amps… Ofcourse with an other power supply.
Thanks, should be more than enough for two fans 
I’ve fitted two 60mm fans over the week end and they work just fine.
The only problem is that they seem to over cool the heated bed causing the bed to remain powered on all the time in order to maintain 50C during a print.[/quote]
Because the bed is underpowered in this design. 
The BUK6215 has to burn 1.5W, it will for sure get hot.
What about this?
https://forum.vellemanprojects.eu/t/additional-power-supply-for-heatbed/7459/1