@dc42:

1. If the heatsinks drop off, they could short out the stepper motor pins. Any damage caused will not be covered by warranty.

Great advice, thanks

@dc42:

2. Heatsinks may reduce the airflow to drivers further away from the fan.

I'd place heatsinks onto the thermal vias of every driver.

Are the thermal vias covered by some sort of laminate or fully exposed like on 'SilentStepstick'?

@deckingman:

using additional heat sinks is unnecessary and possible detrimental.

How can heatsinks be detrimental here?

@GiulianoM:

I was looking at the PCB layout last night… There are thermal vias on these, too.

10x10mm heatsinks are about the right size to be placed on the underside.

Thanks for the reply man.

http://i.imgur.com/WDJyvQM.jpg You can see on the bottom of the image where the labels for the steppers and such are, I assume just above that are the thermal vias, those little pin hole looking spots/pattern. https://youtu.be/mYuZqx8xwTg?t=163 You can see the thermal vias here in this video clearly, shiny copper looking rectangle, the difference that I see is that whatever PCB laminate that is covering the TMC2660s thermal vias isn't covering the TMC2130s thermal vias. Think this is accurate? It's probably likely best to place heatsinks over the 2660s thermal vias, but I wonder why the thermal vias might be left covered.

@T3P3Tony:

What can help if you are pushing 2.4A is to blow a fan over the bottom of the board.

All around more cooling seems better to me than less, even if not entirely necessary, more surface area is good. I am not really sure what 2.4A really means (I know it's current), the datasheet says 2.8A RMS and I guess 4A maybe with proper cooling? I probably don't understand the datasheet very well.

@T3P3Tony:

Update: this older thermal testing post actually shows pictures of the heat spreading on the back of the board:

http://blog.think3dprint3d.com/2016/07/duetwifi-thermal-testing.html

Thanks. I am guessing that the current limit could be blown away by some decent heatsinks placed over those hotspots, assuming the thermal pathway is good.

Hello,

Stepper drivers using TMC2100 (SilentStepstick) have 'thermal vias' which allow for effective thermal pathways. Is there a heatsink placement option for the duet wifi or is the only recommendable heatsink placement is on top of the IC chip?

I'd share a link a video made by Thomas Sanladerer that might help illustrate this but I am unsure if I can share links here.

Thanks!