Fried X5305, can it be saved? Lessons?

[whitecat]

The continous torque a motor can handle is determined by the copper fill. So, a 5308 would have identical torque to a 5303, or 5304, because they all would have 24 pieces of wire in the slot (identical copper fill).

And, cooling characteristics are dependent on how much fill the motor has, as it correlates with total power output - something to have in mind when designing stators. I had to redesign a very badly designed line of motors in one instance where original designer pushed thermal design to it's limit, leaving only a few degrees C between running on full power in max. ambient temp, and burning the motor up. Needless to say, over 50% of them in regular use burned up within a months time, and that's when I got to do the redesign. You can't always be trying to cram max power output in minimal package size, there are sometimes other considerations such as longevity.

 

[sabb]

Years ago I ran a Motor rewinding shop and most magnet wire was at least class F(155c) to burn out this bad it went alot higher than that and now I would wonder if the magnets still have any strength left.

Anybody out there know how tolerant of heat the magnets that crystalyte uses are?

Stephen

 

[Kiwi]

Interesting you say that. I once tried to push a stator out of the hub, a good one, and I couldn't. But this time I could, although I had to basically stand on it to get it out, I thought, wow, I got it out, I never use to be able to do that. So I wonder if the magnets gave up a bit. Still grab a screw driver pretty good.

 

[velias]

Wait why is no one commenting on the fact you had 2 riders at 350 pounds total
on your bike?
Seems like you should lose some weight or lose a rider.
Heres your solution: use a separate bike for each person.

 

[auraslip]

Wait why is no one commenting on the fact you had 2 riders at 350 pounds total
on your bike?
Seems like you should lose some weight or lose a rider.
Heres your solution: use a separate bike for each person.

I'm more curious on how you fit two people on a bike.


Also I regularly pull my trailer with 200lbs worth of equipment on it. Not up many big hills, but the motor is a stock ebikekit 9c.
Am I in danger of burning it out?

 

[Kiwi]

2or 3 or sometimes 4.....

Note the front wheel drive it a NC 9x7 48v 40a, the rear is 5305 at 72v50a

 

[amberwolf]

Also I regularly pull my trailer with 200lbs worth of equipment on it. Not up many big hills, but the motor is a stock ebikekit 9c.
Am I in danger of burning it out?

I doubt it. Mine doesn't complain about a trailer full of stuff, dog food (or dog); that's usually over 200lbs. Plus the bike itself (DGA; 80lbs? maybe less), myself 150-160lbs. I don't go fast when pulling the trailer, maybe 15mph max, typically, less if I am trying to go farther. Also not accelerating hard, and it's flat here. (but the pavement heat is bad, and it's fairly dry except the last 2-3 weeks or so, making it harder to cool).

 

[John in CR]

Also I regularly pull my trailer with 200lbs worth of equipment on it. Not up many big hills, but the motor is a stock ebikekit 9c. Am I in danger of burning it out?

It depends on the controller current limit and/or how much it slows you down on the hills you do have. If up the hills the extra weight slows you to well below 10mph, then even a low current limit can still cook your motor because the motor gets pushed into it's very inefficient range of operation. Then much more of the electricity gets turned into heat inside your motor. If you have your current limits set fairly high so your motor runs pretty hot with just you on it, then you're much closer to the threshold. If you don't have a temp sensor, just stop and feel your motor after the hardest climbs and you'll quickly get a good idea of what is strenuous on your system.

John

 

[ryan]

Ouch. This looks just like mine. Did you rewind? Replace? Buy a different motor?


View attachment 2

 

[Kiwi]

I was having a look at my motor again today after reading your thread, thinking, is it really dead? Could it just be the halls. I would like to get hold of, or make a tester, I think its pretty easy to test the halls. But the insulation is fallen off the winds, you can rub it off with your fingers. Its fried.

My motor did turn but with a very bad sound, and only under no load.

I have purchased a second hand motor that someone wound the cables round the axle, so the coil is fine. Will swap the cables and axel if needed and build a new motor from the best bits.

THERMOMETER!!

It has taught me a lot, forced me to understand more why heat is generated, and how to avoid it, or at least be mindful of it.

I am interested though to find out what a rewind would cost, as I would like to have a 5306.

 

[karma]

rewinding is cheap but time consuming. i would still buy a new motor. it always good to have a spare.

you will see what i mean when you start removing the old copper and cleaning up the stater.

i say go for it. and please post results.

cheers