Conversion Kit, motor electric lead shorted

[1kenthomas]

Hi all, first time poster, please redirect if appropriate.

I have a Currie conversion kit motor that seemed to stop working yesterday (blown fuse). After isolating access to the circuit powering the motor, it seems to have a short-- protected current blows a fuse, direct current without fuse protection sparks with no turn of motor.

Motor will spin in at least the opposition direction with gearing (still attached to wheel). However, there is clear internal noise and resistance that was not their previously. Replacement brushless system already ordered.

However, assume I was 60 miles away from home with my full mobile mechanical kit. Any tips on what might be wrong and how I would repair it? Thanks in advance.

 

[Ann M.]

@1kenthomas , I've worked with Currie products for 14 years, which system do you have and type of battery, please? Can help you better, then.

 

[1kenthomas]

@1kenthomas ...which system do you have and type of battery, please? Can help you better, then.

Hi Ann M., thanks very much.

This is an IZIP-KIT1 with 24V lead-acid. Note that I've shorted the fuse on the SLA for testing, since it kept blowing, and am applying current directly to the engine leads for testing. The motor does turn in both directions but there seems to be an unusual amount of resistance and a grinding noise.

 

[1kenthomas]

UPDATE: motor cap removed. The first spring at the top of the picture was intact, the second had been ground into the motor; small pieces were around the casing. But the real problem was the physical short which occurred...

 

[1kenthomas]

UPDATE: the motor is working again. I soldered the broken top housing (and brush) in relative place and (after some efforts to keep the brushes in place) replaced the cap.
Not sure I would ride with it in the current condition (certainly not without a fuse!), but the motor is functional (likely at reduced power).

 

[J.R.]

You have a 4 brushed motor with the brush at the 12 o'clock position completely broken lose. That design is fairly straight forward, almost identical to a motorcycle starter motor in design and size. It can be strong and serviceable, but requires a lot more maintenance than a brushless motor. You should be able to get the parts needed to repair your motor at a reasonable cost, but you won't be able to use it as is.

Some really good information for your motor in these links:

https://www.electricbike.com/2014-ezip-trailz-lithium/


https://endless-sphere.com/forums/viewtopic.php?f=2&t=62869

For reference, what it should look like new:

 

[Ann M.]

Nice pic, J.R.! Yes, these little 450 watt brushed motors were not really designed for easy rebuilds and we've seen one of these motors short, pull too many amps and then fry the controller. So yes, get the fuse replaced.

 

[1kenthomas]

Thanks again all.
Does anyone know an easy/ish way to remove the PCB board that the brushes are attached to? (I'm feeling stubborn and will probably pull it apart again now, desolder, add some kind of spring, and try to effect a more permanent solution).

Also, the first article linked by J.R. mentions 48V(!?!). How far is it reasonably safe to operate these? Can I chain in an additional 12V (from a Li pack) and operate without serious damage to the motor?

And as for my "stuck on the road" scenario, in case anyone comes along: this required a soldering iron, good lighting, various pliers and equipment, etc. If you have some subset of these, it could be done on the road, but I doubt it would be useful unless you had no other choice. (I might add a DC soldering iron to my gear... )​

 

[J.R.]

Thanks again all.
Does anyone know an easy/ish way to remove the PCB board that the brushes are attached to? (I'm feeling stubborn and will probably pull it apart again now, desolder, add some kind of spring, and try to effect a more permanent solution).

Also, the first article linked by J.R. mentions 48V(!?!). How far is it reasonably safe to operate these? Can I chain in an additional 12V (from a Li pack) and operate without serious damage to the motor?

And as for my "stuck on the road" scenario, in case anyone comes along: this required a soldering iron, good lighting, various pliers and equipment, etc. If you have some subset of these, it could be done on the road, but I doubt it would be useful unless you had no other choice. (I might add a DC soldering iron to my gear... )​

I know a guy that rides an eZip Trailz with the same system as yours, he's ridden it for 3 years all around town. It's been a solid performer for him. I've also seen the eZip Trails ebike advertised on local Craigslist, always seems to be priced at a bargain, $300 +/-. EBR's eZip Trailz review here. New, leftover stock appears to still be available as well for $323.42

http://www.saleawayscabana.com/inde...i43q1xBiicFLL5x7nkBDXti0F8qK0fqkeVBoCmHnw_wcB

There's also plenty of parts still available, including lithium ion and SLA batteries. Additionally the motors are also available for $130.00 and $145.00.

https://electricscooterparts.com/eziptrailzmenselectricbicycleparts.html

http://www.monsterscooterparts.com/...ss-electric-motor-9-tooth-chain-sprocket.html

This is a 24 volt system, with two 12 volt SLA batteries wired in series to yield 24 volts (max ~26 at full charge). Considering the motor, controller and wiring are all designed for 24 volts, I think it would be unwise to over-volt this system. If you look at the first link in my post above, it shows what can happen over-volting this motor.

Good luck with it!