cooling query

[ericrw]

I`m wanting to place my ESC on a bed of foam to ensure it is not subject to vibration. The question is which side of the ESC should lie on the foam bed, in respect of keeping it cool ? Eric.

[Peter Beeney]

This is not really a good idea, Eric. Doing things like this might soon cause the ESC to overheat. There won’t be enough vibration to affect it anyway, the trick is to get a nice air flow all around it if you can.

Solid state electrical devices are largely unaffected by movement, it’s only when they they contain something like a crystal that is in itself a vibrating device that might be upset by any extraneous motion.

Try and keep the whole drive train cool, motor, ESC and battery, if you can.

PB

[ericrw]

Thanks for that Peter, I will place it on a Velcro mat but I would still like to know if there is a correct side to place the Velcro on the ESC .

[ken anderson.]

hello Eric-I always mount my esc's with Velcro...keeps them from moving around etc......and was always told to leave the heat sink side out in the open....if fitted.

ken Anderson ne..1 Velcro dept.

[Peter Beeney]

If one side of the ESC is flat and one side is a bit bumpy put the Velcro on the bumpy side. But check it straight after a flight to see how hot / warm it is anyway. Most likely will be ok, but if the heat can’t escape quickly enough it starts to build up, this is the dreaded ‘thermal runaway‘ situation.

PB

[Ernie]

Hi, It's important to remember that you need to provide an outlet for the air. It should be larger than the intake area,'cos you'll remember from your science lessons that hot air expands, so there is more off it, needing to escape, and we don't want it circulating around our expensive electrickery

ernie

[Gary Manuel]

Just reading this thread and another question occurred to me. Hope nobody minds me jumping on this related band-wagon.

The flat side of the ESC is the heat-sink side and should be the side exposed to best air circulation to achieve the best cooling effect.

Does anybody bother to cut the heat shrink away from this area to improve the thermal efficiency (let heat out quicker)?

I have done it on a few ESCs and am pretty sure it helps. The problem is, the area you want to cut away, is the usual place for the manufacturers label, including ampere rating. Once its cut away, the info has gone forever - and possibly the warranty!

[john stones 1 - Moderator]

No Gary I don't, have seen and heard it suggested, but I always wonder...why did the manufacturer shrink wrap it if it needs to be uncovered ? I over esc mine and am careful with prop selection and my stuff don't seem to get any worse than slightly warm Pushy Cat has no cooling holes at all and that's the same.

John

[Pete B]

I normally cut away the heatshrink on the cheaper ESC's - why make it work harder than necessary? A felt-tip pen solves the ID problem

I also use a UBEC on any model with more that 4 servos, or 4 cells or more - and I cannot recall when I last lost a model to an ESC expiring.....

Every little helps, as Tesco would say.....

Pete

[Simon Chaddock]

If you are really worried about cooling you can always replace the flat heat sink with a much more efficient one with 'fingers' that stick out into the air stream.

With really efficient cooling fins the ESC can be completely buried.

In this case the heat shrink has been cut away and the original flat heat sink replaced but it does require heat conducting grease to be applied and the heat sink to be positively held down on the MOSFETs.

[Barrie Dav 2]

Pete, wasn't that something to with a bishop and an actress? Something to do with subscriptions to cathedral funds I've always understood.........