> One of the mistakes folks make it to attempt to make the box completely > sealed. You really can't seal a box effectively without going to extreme > measures.
Here's a really interesting video dealing with trying to seal bicycle hub motors. https://youtu.be/gwlbAJLzI_w?t=1242 It's a long video, that link should skip you to 20:42 into it. (I usually watch at 2x speed, takes a few seconds to get used to). The guy giving the talk is the guy who designed the CycleAnalyst, he more or less founded the E-bike scene in Canada 15 years ago. At this point he'd been running his factory/shop/service center for 7 years, and he's sharing his experience. In summary: 1 - When motors/controllers/etc get hot, the air inside expands. Some air finds a way out to equalize pressure. When it cools it contracts, air finds a way back in. It brings water and humidity in with it. 2 - You can seal around the wires really really well. That's nice, water still gets in. How? 3 - Inside the wire, in the "air gap" between the wire metal and the wire insulation, the suction is enough to suck water up it like a straw. Fine, so seal around that as well on both ends. That's nice, water still gets in. How? 4 - By wicking inside the stranded wire itself. Circular hexagonal packing/tessellation is only 90% dense. Water, umm, finds a way. 5 - Gradually in wet areas (Vancouver, rainy winters, similar to Seattle), this works like a pump. Ride bike, heat air, stop bike, suck in water. Eventually the whole motor fills with water and rusts solid. 6 - Give up, paint the motor internals with waterproof enamel, drill some holes in the motor case for the inevitable water to drain out, problem solved. Mirrors much of what Bill said. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
