Splitting a Heinzmann Direct Drive BLDC Hub

[Joe.B]

Morning everybody.



This is my first post here so I guess a quick introduction is in order.

I’m in Newcastle, England, and just starting to get back into a little bit of ebike tinkering after a few years without much exposure to the field.

I have just electrified our Nazca Quetzal recumbent tandem using a Shengyi geared hub and Grin Tech controller/display. My next task is to get our Circe Helios cargo bike back on the road after the failure of Heinzmann Direct Drive system that has been fitted for about 12 years. (Motor & controller OK, BMS completely dead).

For this bike I intend to use the existing Heinzmann Direct Drive motor with a Grin Baserunner controller and new 36v battery from UPP. Before I start I want to replace the phase wires on the hub due to damage caused by friction with the rotating parts.

Question is: Can anyone offer any advice on splitting the Heinzmann DD motor?

Those familiar with the Heinzmann DD BLDC will know that it has no visible screws holding the two halves of the outer casing together and appears to be bonded. I am worried that the bond might be so strong that spoke flanges could snap off if I try to force it open using a puller. I’ll also need to de-lace the wheel which is a bit of a pain.

Any advice very welcome.

 

[fechter]

As far as I know, the halves of the motor are threaded and you unscrew them to take it apart.

 

[Joe.B]

As far as I know, the halves of the motor are threaded and you unscrew them to take it apart.

That's interesting, glad I asked the question now, defiantly wouldn't have ended well if I'd started trying to open it up using bruit force.

 

[fechter]

I haven't seen any of the newer ones apart, so it's hard to tell. It may be just press fitted together like an A2B motor.

If you look on page 2 of this topic, you can see the DIY tool I used to split the A2B motor.

A2B Metro restoration / modification - Fechter's first Ebike

In the factory, pressing them together would be a lot faster/cheaper than a threaded shell. The threaded ones would usually have some kind of feature on the shell to fit a special tool used for tightening, but it may be hard to tell.

 

[amberwolf]

Before you open it, mark the casings so that you can tell with certainty which way they are currently fit together, so you can put them back together identically. Alighnment may not matter, but if it does and you don't know how they were originally, it'll be tough to get right.

 

[peregrine0907]

If you motor type is PRA 180-30, then the motor cover is made by press fit. You need some specific tool and fixture to reassemble it. But I will suggest you just sording the cable wire if possible.

 

[Joe.B]

I decided against trying to split the motor after someone who has extensive experience with these reporting that he had split 4 but only successful reassembled 2.

Instead I removed the phase connector and outer insulation which then enabled me to be able to slide some heat shrink over the damaged area.

 

[fechter]

Good approach. Hopefully the hall sensor wires are still intact.
You'll have to devise a way to keep the wires away from the moving parts. There isn't much room.