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Water Proofing Electronics

I wanted to expand on our knowledge of brushless motor technique. I haven't seen any good write-ups on here for brushless motor waterproofing, but a lot of people talk about it. I recently picked up 2 Novak 18.5T BL sensored crawler motors and I thought I would add to the waterproofing knowledge base on our thread here.

First I took the motor apart. For this particular motor there are 3 short screws in the top that house the sensor board. There are also 3 screws down bottom that secure the bottom cover with bearing. The obvious area of interest is the sensor board. Here is the motor all torn down:
photo.jpg


Next, I took a close look at the sensor board. It consists of 2 circuit boards on either side of a ~1/8" thick piece. There are wires that run between the two boards that pass thru the piece. One for each of the six colors on the sensor wire. Here is top and bottom of the sensor board. Of note, there is also a gasket type piece. It is thin and lays on top of the board between the sensor and its housing (I presume to prevent shorting if these two were to contact one another).

photo2.jpg

photo1.jpg



My assumption is that if both sides of this board are sealed, the motor is safe. I do have concerns that the only part of the circuit board I can get to are the exposed sides. The sides that are fixed in the piece cannot be reached, as far as I can tell. I intend to liquid tape the exposed sides of the sensor board as this has been a dependable waterproofing method for me so far. I won't do this until I have some corrosion X.

This is all I have for now... I'll post back later when I have some corrosion X to apply to the windings/magnets/rotor. It'll likely be several months though. Please let me know if I am missing anything or you have any advice to keep me from cooking my motor.
 
This is all I have for now... I'll post back later when I have some corrosion X to apply to the windings/magnets/rotor. It'll likely be several months though. Please let me know if I am missing anything or you have any advice to keep me from cooking my motor.

hibbs - check out jthellfire911's thread in the 1.9 section. He's got some photos of his corrosion x process on a pro4. Start with posts 76 and 77.

"thumbsup"
 
Well, i plasti dipped my cheap ebay servo and it works wonderfully. used marine grease to seal the bearing. Well, i just aquired a hitec 7955tg and for some odd reason im worried it will mess up due to it being quite a bit more than my little 30$ ebay servo lol. What do you guys think?
 
There is a product out now called 'Wet Suit' and 'Invisible Man' in an aerosol can. You spray down your electrics and it dries into a rubberized film type of coating. A few coats is all that u need. Apply more as needed to make it the thickness u desire. Caution: if the coating gets scuffed or over flexed in a vital area it will leak. You can always just hit it again with a couple of coats and be back in business It would work great for the folds of a tied balloon. A big PLUS to this item is that it dries clear. It does leave bubbles however if u try to do it all in one coat. Bubbles are bad b/c they cause the product to fail prematurely as it goes through wear and tear. If ever you need to repair/ re-coat or have one of those OOPS moments that we all do it's easy enough to just peel away and start over.
Keep a can w/ you and spray it on your battery connection before a run and u can peel it off when u r done until the next time. It takes only a few minutes to dry well enough to handle. Good moisture barrier! temporary or permanent
A friend of mine found it to coat the circuit boards he builds for his led modules, servo testers, etc. They don't short when placed across tools on his bench w/ power to them.
good luck!
 
Thanks to everyone for their input on waterproofing. Been wanting to do this for awhile but I run a sensored brush less and wasn't sure if it was possible to waterproof that setup.
 
can i just put regular grease in my servo to water proof it other than that i bought a project box from radio shack and am going to put my ESC and receiver in it just havnt had the time
 
bit of advice needed ive plasti dipped most of my esc and was wondering do i do the bit in this pic aswell the bit with the writing on it. i know not todo the top part as that will be covered with a plastic peice then the the heatsink

191120125071.jpg
 
PLEASE READ THIS:

Waterproofing with liquid electrical tape or plasti-dip is NOT an appropriate waterproofing method. I can tell everyone on here that you should not use this method if you don't want to ruin your electronics. I recently had a liquid taped MMP die on me.

In reference to using plasti-dip:
Sorry, but this statement is false. My experience has proven this and it has been verified to me by engineers at Castle. The plasti-dip actually TRAPS moisture inside the electronics case..and if you remove the case and plasti-dip the board, there is a chance of pulling components off the board, since plasti-dip shrinks as it cures...

The best method IMHO is to remove the case and dip the board in EPOXY. This is how I've waterproofed my MMP and I have run it completely submerged underwater many times with ZERO issues...

and further, an expert opinion from John Holmes of Holmes Hobbies:

And use a potting epoxy if you want to be safe, it doesn't shrink like many off the shelf epoxies do. I've killed ESCs using regular epoxy before, it shrank enough to rip components off.


plastidip works well to keep water off, but you can't stop water from wicking down the wires towards the board. Wires actually allow a lot of water through. The only way we can really get totally waterproofed is to have copper standoffs for every wire that come out of the epoxy. But, a good potting epoxy does well enough to bond to the board so moisture doesn't move around once it gets in the wires.

It would seem that the only two reliable methods for waterproofing that are 100% (or realistically 99%) are conformal coating and potting or encapsulation epoxy. After reading about these two methods, the potting/encapsulation epoxy sounds like the best approach for our application. The problem I have currently run into is that it is difficult to know what to buy. 3M is a well known brand, but 1.7 oz of their potting epoxy is about $20, this is far too expensive. MG chemicals makes potting epoxy that is much more affordable. 12 oz is ~$32. There are tons of different formulations of these epoxies. We need a clear epoxy to be able to see the LEDs on the MMP.

Just google MG chemicals potting compound if this link is old and no longer works.

MGC-832B MG Chemicals 832B Epoxy Encapsulating and Potting Compound

I am going to purchase some potting epoxy and try it out and follow up here to let you all know the results and what epoxy I used. I will also be trying this out on sensored brushless motors as seen in my post above.

I feel that it is very important to further our knowledge in this area because many, many people believe that liquid tape and plasti-dip work well.
 
Blew my ESC on the weekend after going the liquid tape route. Next purchase, an epoxy waterproofed holmes esc...
 
i want to get some potting epoxy, but i cant seem to find any where that sells it, any help would be nice, i ve looked online, but every where seems to be in bulk, and id rather buy it in a store. thanks
 
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i want to get some potting epoxy, but i cant seem to find any where that sells it, any help would be nice, i ve looked online, but every where seems to be in bulk, and id rather buy it in a store. thanks

Hey Baker,
This is what I picked up. I can't not say for sure if it is a good choice or not. I think it will work well. I haven't got around to trying it out yet. It was $38 shipped and there is plenty enough (12oz) to do several devices. I see you are in Canada, so the shipping may be a bit more. It was $7 for me on $31 epoxy. You should try searching online for 'MG Chemicals potting epoxy' because they are a Canadian company

MGC-832B MG Chemicals 832B Epoxy Encapsulating and Potting Compound

i have a had great luck with corrosion x

When you say you have good luck, could you elaborate on what you have waterproofed, please? ESCs, servos, receivers? And how did you apply it? Did you dunk the item for a while then let dry and repeat?

I just got a bottle in and intend on using it for the internals of a couple brushless motors, hopefully it works good for that.
 
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