John in CR
100 TW
I'm redoing the ridiculously small phase wires of my 9c, and I'd like to maximize the copper with minimal aggravation. I don't fully trust shrink tubing anyway, and trying to stuff 3 shrink wrapped 10ga wires plus the 5 hall wires seems like it will test my patience. I have a 18 and 24ga magnet wire already, so shrink wrapping 3 separately terminated groups of magnet wire, the halls wires, and 2 extra wires (in case I want to add a temp sensor later) into one bundle to go through the axle seems easy enough.
As long as I don't scrape through both the shrink wrap and the wire coating going in, and don't subject it to abrasion or flexing during use I should be good to go. Are there any pitfalls? I was planning to just slightly twist the entire bundle as 1 to keep it more manageable and shrinkwrap nicely, unless there's some electrical reason the 3 phases should be separately twisted as 3 groups.
What's a good lubricant for sliding the harness through that won't damage the plastic shrink tube over time? I recall someone mentioning silicone (I'd go with the type without acetic acid), which sounds like a good idea because it would form a seal afterward and this should be a once in this motor's lifetime thing, but maybe I should thin it a bit to be a decent lubricant.
I've already balanced the sadly out of whack motor covers, and I picked up some SKF bearings to replace the stock bearings that were so crappy I could actually feel tick-tick-tick turning each of the bearings on a brand new motor. Why go to the trouble?...The motor will be used as a ventilated mid drive running at 133V nominal and 75A. Even with sag the motor will see above 140V most of the time. elSteak was running his ventilated 9C at 90A without the heat getting out of hand, so with about a 2:1 gear reduction the higher rpm should make for low stress operation despite a 10kw input. Stator saturation may still be an issue at 75A battery side, so I may need to go lower, but my goal is to increase both motor efficiency and power by using the higher voltage. The higher rpm (I expect over 1krpm) will also make the centrifugal fan effect of the ventilated covers much stronger.
John
As long as I don't scrape through both the shrink wrap and the wire coating going in, and don't subject it to abrasion or flexing during use I should be good to go. Are there any pitfalls? I was planning to just slightly twist the entire bundle as 1 to keep it more manageable and shrinkwrap nicely, unless there's some electrical reason the 3 phases should be separately twisted as 3 groups.
What's a good lubricant for sliding the harness through that won't damage the plastic shrink tube over time? I recall someone mentioning silicone (I'd go with the type without acetic acid), which sounds like a good idea because it would form a seal afterward and this should be a once in this motor's lifetime thing, but maybe I should thin it a bit to be a decent lubricant.
I've already balanced the sadly out of whack motor covers, and I picked up some SKF bearings to replace the stock bearings that were so crappy I could actually feel tick-tick-tick turning each of the bearings on a brand new motor. Why go to the trouble?...The motor will be used as a ventilated mid drive running at 133V nominal and 75A. Even with sag the motor will see above 140V most of the time. elSteak was running his ventilated 9C at 90A without the heat getting out of hand, so with about a 2:1 gear reduction the higher rpm should make for low stress operation despite a 10kw input. Stator saturation may still be an issue at 75A battery side, so I may need to go lower, but my goal is to increase both motor efficiency and power by using the higher voltage. The higher rpm (I expect over 1krpm) will also make the centrifugal fan effect of the ventilated covers much stronger.
John
