MMM water proof coating?

[Snipin_Willy]

I took the case off of my MMM this weekend to inspect the dead fan. While I had the PCB out I used some electric motor cleaner that is safe for plastics to clean off some gunk. There seemed to be a clear coating that rubbed off the PCB, my guess was a water proof coating. Can I use some spray electrical insulator to replace what came off, or is this a send in issue?

Personally, I'd rather spray on an insulator because last time I sent in a MMM it took more than a month to get one back.

[suicideneil]

Its a conformal coating designed to offer the pcb some water resistance. Sure, you could happily use some non-conductive stuff to to coat it with again, just dont go crazy and put a 1/2" thick layer on, a light coating would be fine

i have been toying with the idea of filling the case with high temperatire RTV silcone of some sort. that way water and dirt cant accumulate in the bottom and short out. i realize id be on my own but i am after a HV brushless waterproof reversing ESC.

[othello]

If warranty is a non issue you could mould your MMM with resin (scroll to the bottom of this german website for pictures). This is what a forum member of Offroad-Cult did with his MMM ESC.

[nitrostarter]

I've done that with Airplane esc's that I've run in boats to make them water proof. I used 3M's DP270 and it worked great!

well i cant speak german but these are good pics. the next question i was going to ask was what kind of resin - thanks nitrostarter!

[fastbaja5b]

The MMM doesn't look even remotely waterproof to me, I was going to use one in my Slash but the VXL ESC seemed a lot more robust in terms of withstanding the elements. The MMM just looked comparatively fragile.

[suicideneil]

The VXL is is billed as being 'water proof' since it has a sealed case complete with O-ring seals. It aint watertight though, but it does have a conformal coating.

The MMM makes too much power and handles too many amps to be completely sealed- it needs air cooling so hence all the vents. It does have a conformal coating too though, so it offeres a degree of protection; if you wanna get your model wet, buy a boat is what I always say.

I do lie the German dude's idea- makes it look rather like an old Mtronics esc....

[BrianG]

Originally Posted by suicideneil

...I do lie the German dude's idea- makes it look rather like an old Mtronics esc....

Would definitely make repairs "difficult". I wonder if that voids the warranty?

[suicideneil]

That might be a slight possibilty...

[Joe Ford]

Originally Posted by BrianG

Would definitely make repairs "difficult". I wonder if that voids the warranty?

It does, and I already informed that gent that every controller he makes and sells like that will be sold without warranty. Hope he lets his customers know that...

[Snipin_Willy]

I'm not sure a confirmed answer has been posted yet: will recovering the bottom of the PCB with some type of water protective coating void the warranty?

Originally Posted by Snipin_Willy

I'm not sure a confirmed answer has been posted yet: will recovering the bottom of the PCB with some type of water protective coating void the warranty?

Dielectric grease? It comes off easy.

[J57ltr]

Originally Posted by alangsam

well i cant speak german but these are good pics. the next question i was going to ask was what kind of resin - thanks nitrostarter!

It's called potting compound. Usually you pour it in slowly then pull a vacuum on the item to remove any bubbles (you also do this just after mixing). Sylgaurd (it's clear and MIL spec) is one I have used before along with another that comes in a package that has a divider you press one side and it flows into the other then you mix it in the package and cut a corner and pour. It works great but you will never be able to work on anything again as it is nearly impossible to remove. I have used it to make LED parking lamps for the Monster Garage Bronco rock crawler after a guy I know bought it and I rewired the entire truck. I had 2 LED go bad and just ended up making a new one becasue it was too hard to mess with. It's privatly labeled for a company here in Houston but it comes in black, Blue, Orange, and I think Yellow. It's a 65A Durometer, is polyurethane and would suit your purpose. But like what was said before you have no warranty and I doubt they would even attempt to repair it.

Jeff