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Old 03-03-2016, 05:47 PM   #372 (permalink)
e*clipse
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Jiminy Xmas!!!! WoW Paul - you're awesome!!!!

How fast was the motor turning at 375V?

Why did it intermittantly depower when it got near the top speed? I thought it would just top out smoothly like a DC motor when the BEMF matched the input voltage. That's strange...

Just a couple mechanicy things, to answer some questions about orientation and mounting.

- Freebeard: I would recommend NOT spot-facing the backs of those mounting holes. That will most likely result in a stress-riser, leading to fatigue failure. Aluminum is nototious for fatigue falures; I personally wouldn't push my luck by removing material in a highly stressed place.

- Paul: those square thingeees are mounting flanges for halfshafts. For independant suspension drivetrains (front or back) the halfshafts need to be free to change angle without changing the output speed.

This may seem pretty strange, but a universal joint causes the output speed to vary throughout a revolution. This is why they're not used (anymore) on halfshafts, especially on FWD cars. Here's a description of the issue:
https://en.wikipedia.org/wiki/Universal_joint

Fortunately, there are a few good solutions, in constant velocity joints:
https://en.wikipedia.org/wiki/Constant-velocity_joint
Most common are rzeppa joints and tripod joints. Tripod joints don't allow a lot of articulation, but allow in-out movement for suspension articulation. They are frequently found inboard and FWD cars. For my setup, I'm going to use the Rzeppa joint. There are 3 variants made by the VW automotive group (this includes Porsche and Audi) They are very robust and commonly available (relatively inexpensive).

Regarding orientation - I would HIGHLY reccomend orienting the MGR like Toyota intended. The reason is the oil system, and Astro pretty much summed it up. The oil system flings oil into some "containers" that hold the oil and slowly let it dribble out to the gears, bearings, and motor. The oil is used to cool the motor. Any other orientation will pretty much defeat the lubrication/cooling system because the oil won't make it into those containers.

Anyway - AWESOME job getting the MGR running I am estatic!!

- E*clipse
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