Fisher 1.0 cooling

Hi there!

I thought about adding some cooling to the Fisher 1.0 electronics.

Firstly, I want to install a 4cm 12v fan to one of the holes meant for the RRP Logo.
For this, I want to convert the 19V operating Voltage of the printer to 12v using a simple step-down converter.
Unfortunately, I didn't find any design files of the RRP Duet on github.
On the Duet 0.8.5 +19v and GND are exposed via pins.
Is that also true for the RRP Duet and is it save to draw
additional power (~100mA max) directly from the Duet?


Secondly, would there be any benefit in adding heat sinks to the Duet?
I have some double sided heat conductive Tape I used for a project and some Aluminium heat sinks.
Does it make sense to add a heatsink to the low-power sam3x8e?
What other parts ( e.g. Stepper drivers) may benefit from
a heatsink?

Thanks a ton!
La_doc

Edited 3 time(s). Last edit at 10/25/2015 06:09AM by La_doc.

Probably wont hurt, but have not noticed any significant heat problems on the Fisher or Mendel, and I've done 24 hour prints on both machines

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RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

If you want to cool the Duet, don't use stick-on heatsinks. They may do more harm than good by obstructing the airflow to the PCB. The driver chips are designed to be cooled via the PCB, not the top of the chip.

I think it is wise to cool the Duet with a fan whenever it is mounted horizontally in a confined space, because that reduces the convective cooling. It's probably less important in the Fisher 1.0 if the extruder motor drive current has been reduced with the change to a geared extruder. Have the fan blow air over both sides of the PCB along the line of the driver chips. Here [www.thingiverse.com] is the Duet and cooling fan mount that I use in my large delta.

You can buy a 19V 40mm fan from RepRapPro, which would be simpler (but not necessarily cheaper) than adding a 12V regulator. Maybe a 24V fan would work well enough on 19V.

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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].

Thanks!
I just found a thread in the forum about adding a 5V fan to pin 1&2 of the Expansion header.
Apparently the onboard converter of the duet 0.6 can provide up to 2A on the 5V rail.
Since you can run a paneldue of the duet 0.6 and 0.8.5 a small fan certainly won't hurt.
I guess I'm going to go the same route, I have a better use for the step-down converter anyways.

I've just bought a 19V fan from RRP to do exactly this, not because I think it needs it, just because it doesn't seem like a bad idea for the long term life of the board.
I've had 3 Fishers running for 12 hours doing non-stop printing and didn't see them blink once.