o00scorpion00o wrote:Hi Paul,
Is there any chance Paul you could install a temp sensor and some kind of display so we could know when to stop? That might save a lot of motors. But I've put 3500 watts into the phase wires and not got them hot, warm but not hot!
I shall be installing my own temp guage. Just a simple lcd display one- ebay for a few bucks. I'm drilling another hole in the axle from the other side- one phase, hall lines and temp sender line in one side and two phases in the other. Phase wires will be unneccessarily large at 10 awg. I'm only doing the temp thing out of curiosity- once I've got my amps in check it will be fine. Most people won't need to know as long as they are sensible and don't overvolt their motor. Not sure how many of those people exist on ES...
Well to be honest, my 320 rpm mac never got hot only on one hill for a few miles at full throttle 32 mph, I was astonished how fast it can climb hills, the mac is so powerful at 3.5kw makes the magic pie seem a lot slower for the same power!
I think more voltage is better than current in some applications, because 3500 watts on 60 volts is around 60 amps battery current and 3500 watts on 36 volts would be 97 amps, that's a hell of a lot of extra current, and at 36 volts the motor has a greater chance of bogging down, creating even more heat. So I think 60 volts is a sweat spot for the mac, by my experience, I have not burnt the windings at all they look as new!
I damaged the clutch and key way, but Paul has (or nearly has) a new axle with a much tighter key way fit, I'm not sure yet if he has the newer design clutch ?
I know Paul does not recommend the mac above 52 volts, but I think I would rather more volts than dump more current. With the mac you need a lot less current than with direct drive for the same torque, so I think people automatically assume they need the same power with the geared hub!
I did a range test one day with the mac, no pedalling at all at 20 mph and got 25 miles out of 8.5ah, that's impressive!
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