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Old 03-08-2021, 10:58 AM   #41 (permalink)
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Quote:
The synchronous speed for an AC motor is determined by

the power supply frequency, and
the number of poles in the motor winding.

The synchronous speed can be calculated as:

n = f (2 / p) 60 (1)

where

n = shaft rotation speed (rev/min, rpm)

f = frequency of electrical power supply (Hz, cycles/sec, 1/s)

p = number of poles

Electric motors - Synchronous speed vs. frequency and no. poles
I'd hazard it would only be running at like 600 rpm due to the number of coils in it. At 40rpm/v, it would only have 15v of back EMF, and the rest of the 208v or whatever it peaks at would have to be dissipated across the coils. It would get hot in a hurry.

The reasonable thing to do is to check the frequency of the output when spinning it. I'll do that next time I'm mucking around with it.

Edit:
1200rpm.

It's giving me 67hz at 1350rpm, which works out nicely to 1200 at 60hz.


Last edited by Stubby79; 03-08-2021 at 11:34 AM..
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Old 03-09-2021, 01:11 PM   #42 (permalink)
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I love it when I say goofy things that make people do their own research
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Old 03-09-2021, 01:59 PM   #43 (permalink)
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ARRG! I want that 30 seconds of my life back, you crook!

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Old 05-04-2021, 10:53 AM   #44 (permalink)
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My job has been getting in the way of having any interest in working on anything. Well, not any more...

Finally got back to work on the electric bike/motorcycle yesterday. Swapped out the knobbly front tire for a street tire, cleaned up the severely rusty and ineffectual front brakes. That was as far as I got yesterday...

Just clapped a controller and battery in it for testing purposes, and took it for a very early test ride.

It worked much better than I thought it would! The motor appeared to have a wobble or imbalance when spinning freely(without a wheel/tire on it) on my bench. Was expecting it to be a deal breaker on the road...didn't feel it in the slightest. Bullet dodged; phew!

Thrilled. Sooo much more to do on it, though...this was the bare minimum to test it...smooth tires and operational brakes.

Fork angle is very laid back, like a chopper (and certainly resembles one with that 21" front wheel) and came across as alarming how much effort it took to get it to turn compared to what I'm use to, especially for a "bike". How close I was sitting to the handlebars didn't help, as did how low the seat was...very much like the height and position I'm sitting in on my office chair typing -- nothing like the leaning down on the handlebars, able to stand to make maneuvers position I'm use to riding in. Very stable none the less. I see why big old Harley riders look like they're just sitting back doing nothing. Not sure that's what I want, though I like the look.

Welp, time to tear it apart. Have a wider rim, tire and and proper-sized spokes to put on the rear that I didn't have when I first started putting it together. Then I need to decide on the rear suspension...was going to go a bit lower, don't think I want to any more though...'course, I can raise my butt by installing an actual bicycle seat, but that won't do anything for the fork angle. Decisions, decisions...

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Old 05-05-2021, 10:20 AM   #45 (permalink)
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Probably too much trail built into the fork. Harley riders like a big stable straight road ride because most of the roads are straight or high speed freeways and twitchy steering is disconcerting.

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