Electric Brompton stopped working.

[Robert M]

Hello Jerry,
I am not sure if you are still active on this forum.
I was wondering if you could help me with the "tool" for dismantling the planetary gearing on a tonxin motor. Could you send me a photo (with a ruler on it) so I can see how it looks. I assume thee trick is to pull the sun gear ring and the planetary gear rings off from the center shaft. I would like to replace the whole friction gear system with a proper toothed planetary gear system. This might be slightly noisier but it should be a bit more efficient. The other aspect I would like to change is the freewheel / uni directional clutch. I am using the motor on a Brompton and I would like to change the direction of rotation such that the cable enters the motor on the right side which makes folding easier. I had twice damage to the cable at the point where it enters into the hollow axle because of the folding action. Hope you are still around and can help. Thanks
Robert

 

[Deleted member 4366]

It would be a lot cheaper and easier to chuck that motor and treat yourself to a nice Q85 motor, which is the same size, but a lot more powerful and reliable.

 

[Robert M]

Thanks d8veh for your comment.
>>a nice Q85 motor, [/quote]

Possibly yes, but then the cable would still probably be on the same side.
I am unfamiliar with the Q85 motor. Why should it be better than the Tongxin of Bafang motor? Could you send me a link for more information and where to get this motor and how much is it.

Robert

PS: I am in the UK

 

[Deleted member 4366]

You get them from BMSBattery.

They're better than Tongxins because they don't break, you can get more torque out of them and they're cheaper.

 

[jerrysimon]

See here for how to take the Tongxin apart.

https://www.flickr.com/photos/45051578@N05/sets/72157623881672012/

Ignore the intial ones where I remove the roller brake bossing. The only tool I have is the one to take the case cover off.

I have never stripped down the internals more than whats shown in the intial pics where I removed the bossing and stripped down the clutch as shown.

The other pictures were sent to me by someone else who stripped one down to remove all the roller bearings and ring that was prone to cracking on the early units. There is a post on here somewhere that details it.

Beyhond that you will need this other tool which I dont have.

In my experience the larger Tongxin (not the Keyde motor) has proved very reliable in smaller wheel setups.

It is also virtually silent when running

Regards

Jerry

 

[jerrysimon]

There is also a good video here of a rear tongxin motor strip down, showing the typical cracking of the ring as discussed above.

Jerry

 

[Robert M]

Jerry,
Thanks for your excellent help.

Only once needed a tool to get to the inside of the motor when I just used a big enough rubber coated tool band used to remove the oil filter from my car.

The "other" tool is easy to make, I have access to a big lathe at work.
One question is, do I need to to tighten the screw with the allen head tightly so as to deform the outer ring of the gear assembly in order to pull everything off from the central axis or is it just necessary to apply a bit of judicious levering slowly over cross to lift the gear assembly off the central axis?

Thanks again
Robert