I think you would have to offer the header as an optional connection for diys. I feel people who would want to make sure nothing can happen would probably hardwire the 2 together. Commercially speaking though the headers and potting is clearly the faster and effective way to go. But how would you deal with repairing returns? Scrap em and give a new one? Seems expensive (in the long run) if so
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The cost of replacements will depend on the frequency of returns. Say I only have a failure rate of 3% or less. Then simply replacing those failed units with new ones isnāt that high of cost relativity speaking. Especially if Iām selling units at 3x COGS. Of course this all depends on failure rate of which I have no data forā¦yet. Thatās why I want to bullet proof this design and therefore why Iām spending a lot of time on this part.
I probably wouldnāt go through with potting my controllers until I had data to go off of. So say after a year of being on the market I can see if my failure rate would allow for potting.
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As @Flasher mentioned, itās difficult to get brushes in-between the boards and ensure with 100% accuracy that youāve gotten every little nook and cranny covered, because you canāt get to the inside after itās assembled. I donāt trust waterproofing done prior to assembly. I have failed Evolve ESCs that failed from this exact situation.
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Thatās not waterproof, thatās water-resistant. The best skates are both, not just one. Water is bound to get inside at some point because seals fail.
This isnāt serviceable.
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I think itās nitpicking to say that every part of the ESC needs to be that waterproof, thatās what the enclosure or casing is for. Make sure that is doing what it should in the first place. There are more parts in the enclosure that isnāt waterproof so donāt see why the ESC would need to be waterproof (more than coating). With coating it will have a good protection, if more is needed there are other build problems if you get that much water into the system.
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Because they fail, thatās why. I donāt like when they fail.
In a bendy, ultra-high vibration environment like a skateboard, almost every seal fails eventually.
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So true but any form of vehicle or equipment that is exposed to the kind of abuse we put them throught should be build to handle it and be serviced regularly. Anything else is false safety.
Iām specifically referring to ābuilding it to handle itā.
If water seeps in through a seal, the skate should still work. For a long time.
Thatās all.
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Iāll do my best to enable reliability. Thereās so much to balance between also designing for manufacturing, assembly. and cost. I know potting makes any electronic unserviceable, but it offers a lot of benefits during operation. What if I had a good warranty service for my fully-assembled product? If something is legit wrong then Iāll just swap your broke FOCer out for a good one with no penalty. Of course I wouldnāt do this unless I was super confident that the controller works well within the specified limits.
The alternative is the DIY kit where you set it up and whatever-proof it the way you want from the start.
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In a DIY kit, waterproofing will have to also be DIY.
On a commercially assembled one, you could have it conformal coated, but the solder connections would still need hand waterproofing.
Itās not standard on any ESC I know about to be waterproof. But being able to be waterproofed is a big bonus.
Not much would really prevent that, aside from two parallel PCBs.
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Conformal coating is ok but unless I spring for the expensive vapor deposited stuff then there wonāt be 100% coverage. Particularly sharp corners or edges donāt coat well with typical conformal coating. And yes more coating would have to added after the hand soldering of the motor/DC cables. Otherwise, filling up the whole enclosure with potting is just easier.
Yes DIY kit means DIY whatever-proofing as well. Have it your way. Thatās the point.
2 parallel PCBs is exactly what Iām working on unfortunately. Doing this helps a lot of other factors besides waterproofingā¦ Give and take. Engineering is all about which pros and cons you want to deal with. You can never get rid of the cons. You can only just trade them out for different cons.
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Do whatever you think is best @shaman
@b264 will waterproof whatever esc he gets himself anyways.
Not everyone rides trough torrental rain like he does. (Majority of your customers probably wonāt)
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There would be spacers for the the board-to-board screws. Iām just to lazy to model a simple cylinder 
So I legit didnāt know about the Evolve controllers when I thought this up and looks like this new take on my design has some similarities. This 2-board solution is easier to assemble by only needing headers and screws to connect the boards instead of weird soldering. This also standardizes the control board so it will be the same between the new generation of FOCers. The model is still crude and everything isnāt there, but let me know what you think.
Edit: Sure has come a long way from the original designā¦
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Great that itās modular, makes it easier to replace a broken board, change to a different one and better with a little height than added length/width.
Only thing I would like is for the small connector board to not be on a short side. Possible to have it on the longer side of the board and make it half the height so connectors are on a single row?
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Having the connector board where it is enables the type of enclosure Iām looking to do. I havenāt talked much about this, but Iām looking at doing a custom extruded aluminum enclosure that maximizes heatsinking. Having the connector board on the long side messes up this type of enclosure. Previously I thought that wouldnāt be able to go through with a custom extrusion design due to high MOQs but Iāve since have been shaking hands with people that can help with that
Also, youāre still stuck with the same overall height of the controller no matter what side you put the connector board on. The height of this controller as you see it is about 14mm. It will be a wee bit less with the Little FOCer. I could also switch to shorter/smaller headers that could shave off another mm or two. Either way, Iām trying to make the whole thing with enclosure and all, specifically for the Little FOCer (best for esk8), to have a height of 20mm or less.
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nice stack! whatās the dimensions of this?
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113mm x 65mm x 14mm. What you see in the render only.
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Iām resurrecting this subject since Iām working on the enclosure design. Letās assume the connectors/cables will come out the sides and not affect the overall height of the controller. This would mean that the overall height is simply the height of the enclosure. That being said, whatās the max height of the enclosure that would still accommodate your rig? The taller it can be, the better this enclosure will keep the controller cool. This question is for everyone.
25mm Max would be good so it would fit into a single stack enclosure.
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