Winding Question - Help Please

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silentflight   100 W

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Winding Question - Help Please

Post by silentflight » Sep 23 2018 6:47pm

I've been swapping older Bionx I2C 250 and 350 watt motors into 700C rims as I look for the best solution for a long distance touring ebike.

I have an I2C 250 watt Bionx motor that has a great high speed winding, but it doesn't have bolt holes to attach a disc brake rotor. The 350 watt motors don't like to give much support at or above 20mph, even when driven at 12S or 14S instead of the 10S they were designed for. The 250, OTOH, really likes to run at speed when fed higher voltages. It has a no load speed of 35 mph at 46.5V whereas the 350 watt motors have a no load of 27 mph at the same voltage.

Would like to buy a disc compatible I2C 250 watt Bionx if they made one, I just can't remember if they did- anyone else know?

Maybe another idea would be to rewind the motor myself, but have never opened a hub motor, and would need to locate a 3-jaw puller capable of handling an 8.5 inch diameter hub.

Please share any thoughts or ideas if you have them!

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MadRhino   100 GW

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Re: Winding Question - Help Please

Post by MadRhino » Sep 23 2018 6:52pm

Opening a motor is an easy task. Rewinding one is PITA. Unless you value your time 2$ an hour, you’d better buy another one that has the Kv and size that you want.
Make it fool-proof, and I will make a better fool.
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Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
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silentflight   100 W

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Re: Winding Question - Help Please

Post by silentflight » Sep 23 2018 8:48pm

Thanks, MadRhino.

I'm sure you're right, it can't be economically rational to rewind a motor by hand, but it might be rewarding to try once...

Would still like to open a 350 watt Bionx motor that isn't working just to play around and inspect it. I've only just started googling, but have yet to find a puller that will handle an 8.5 inch diameter "gear".

Harbor Freight has one rated for 8 inches, maybe that will do.

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MadRhino   100 GW

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Re: Winding Question - Help Please

Post by MadRhino » Sep 24 2018 12:29am

You don’t need a big puller, you don’t even need one when it is laced in a wheel and you are used to open them motors. A small puller is enough to grip a hold to the freewheel mount or the disc nount after you fixed a 3 inch washer to them.
Make it fool-proof, and I will make a better fool.
Current bikes
Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
Dirt: https://s20.postimg.org/lbqwr55ml/IMG_0157.jpg

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dogman dan   100 GW

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Re: Winding Question - Help Please

Post by dogman dan » Sep 24 2018 7:16am

The cheap HF puller will do. its not pulling that hard, so a poor angle on the jaws will still work fine on a hub motor, even ones larger than 9"

FWIW, you don't so much use it as a puller as you do as a pusher. hook the jaws on the flange of the motor near the spokes. Undo the screws on the opposite side. then the puller will push the core out the other side. So its pulling the whole wheel off the axle, not pulling the axle out of the wheel.

silentflight   100 W

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Location: Chicago

Re: Winding Question - Help Please

Post by silentflight » Sep 24 2018 6:17pm

Thanks, MadRhino and DogMan for sharing your wisdom on this one.

By the way, DogMan, I recall reading posts from you years ago that often mentioned the windings of the motors you were using and various ways you were getting the most out of each winding by using it for different applications. I guess I'm finally catching on...

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MadRhino   100 GW

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Re: Winding Question - Help Please

Post by MadRhino » Sep 24 2018 7:41pm

Here is the disassembly- reassemby of a DD hub that has much bigger, stronger magnets than a Bionix. When it is laced in a wheel it is very easy. You only need a piece of wood or a rubber mat on the floor.

Make it fool-proof, and I will make a better fool.
Current bikes
Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
Dirt: https://s20.postimg.org/lbqwr55ml/IMG_0157.jpg

silentflight   100 W

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Posts: 119
Joined: May 07 2007 5:42pm
Location: Chicago

Re: Winding Question - Help Please

Post by silentflight » Sep 26 2018 12:21am

Fantastic video.

Being brilliant and all, of course I've already unlaced the motor...

I also unlaced it before trying to remove the freewheel, you'd think I'd learn after a bit.

Anyway, this might answer your question as to whether I value my time!

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