Positioning Heatsink and Fan on Odrive Pro

Support ODrive Pro Support
1

Hi,
I have an issue regarding the positioning of the heatsink and fan on Odrive pro, it seems one can only attach the heatsink and fan to the bottom of the Odrive . But my project demands that I use the motor connected behind the odrive, utilizing the absolute encoder present in the odrive .Any suggestions on where to position the heatsink and fan to get everything working properly??

2

Hi!

If you need to use the ODrive’s onboard encoder, then you can’t use the heatsink+fan, you’d be limited to the heatspreader plate. I think your best bet in that case would be to use a fan blowing on the Pro from the top, or to machine a custom heatspreader plate or motor mounting plate that can bring heat out the sides to a heatsink.

That being said, maybe this isn’t fully necessary – how much continuous and peak current do you need?

For the record, you could alternatively use an OA1 encoder, which uses the same magnetic angle sensor as the ODrive Pro uses – so this could be mounted to the motor, and the ODrive Pro could be elsewhere, with the full heatspreader+heatsink+fan stackup.

3

Thanks for your help.
I must add that 100A of continuous current is necessary for working of my application.
Is there anything else you’d like to suggest based on this information?

4

In that case, you definitely need as much cooling as you can get. I would at a minimum use the heatsink+fan+heatspreader, and use an OA1 instead as the encoder. That will get you at least 80A continuous current, should get you 100A.

A few notes:

  1. When operating at high current, you should make sure the capacitors on top of the ODrive board also has some airflow. I would maybe recommend adding a second fan on top, pointing down, to cool the capacitors
  2. You can increase the thermal performance (and thus maximum current) by replacing the stock heatspreader thermal pads (the green ones) with higher performance ones – these are about 1.5x the thermal conductivity, but will have to be cut to size. You can also replace the stock fan on the heatsink with something like this, which is about 2x the airflow, but will require longer bolts for mounting (and is much louder :slight_smile: ). However, I’d give the setup a shot just with the parts from our store (and maybe with a second fan for the capacitors, or just a desk fan blowing at it), and only put in the work (and the money) to make these modifications if you can’t reach your desired continuous current.