Dismantling and repairing the motor :o

[dominik]

viewtopic.php?p=316448#p316448 Here you can see a few pictures of a disassembled motor and of course pictures of the problems during reasambling.
Sorry there are no pictures from taking of the side cover, as it was very easy, with a few pieces of wood and a hammer.

I added a temperature sensor and thicker phase wires.
Biggest problem was getting the bearing over the thicker phase wires.

[jeff-jordan]

My intention was to connect the kty84/130 between GND (cathode) of the main set of hall sensors and connect the anode to the GND line of the spare set of hall sensors. So I don't need to feed additional wires through the axle/shaft.

But as you've guessed, I can only access the wiring of one set of the hall sensors, while the other is covered by the stator lid.

[dominik]

To get the additional wires through the axle/shaft was the easiest thing.

[bob2.0]

That's the problem.
There is nothing to pull or press against at the stator side of the motor. At the right side I had the brake disc to pull against with the puller...

You use a puller.

You are likely to destroy the seal getting the plate over the cabling. That is fine, they are cheap.

I used a small puller and was able to extend it by 'remaking' it. I am sure there is a photo of me doing this in the thread I described the repair. If not, let me know.

Why do you want to access the halls?

[bob2.0]

Now that tire change is due (after approx. 30 tsd. km with the conti road attack 3), I dismantled the motor and it looks much better inside than I thought (no rust inside).

But some questions related to the semi-dismantled motor: how do I get access to the other side of the stator without damaging anything, where the second set of hall sensors is wired?
I'm just asking because I want to add a KTY84/130 (using the wires of the spare hall connector)...

And what kind of sealing did you use to reassemble the motor? Simply transparent bathroom silicone?

I think I am seeing there two 'triangles of death'.

I think two of your magnets have begun to lift, probably due to rust behind the magnets. They are then touching the stator and all of that black dust is those two grinding away and depositing around the wheel.

If you put a small thin screwdriver at the gaps of those, with the rim, and just tap very gently, if they move then they are rusted and the glue is shot. If you are super lucky you can sand the rust off and glue them back, making sure for the glue to seal up the magnet.

If you don't do that, they will swell further, eventually overheat from friction with the stator, demagnetise, and you will get a 'hall sensor' motor fault. Or, if you are seeing that already, that is what has happened.

If you have a gauss meter, check the magnetic fields around those magnets.

[bob2.0]

That's the problem.
There is nothing to pull or press against at the stator side of the motor. At the right side I had the brake disc to pull against with the puller...

I do not appear to have taken a photo of that state. I used a 3 arm puller, I think it was only an 8" but I had to take the arms apart and extend them. I was going to show you that 'tip' but it was just to get enough reach from a puller that is not super-sized.

So the answer is, just a regular puller, but modded to get enough length. It just pulls off. Then just drag it off the axle, I tried to be nice about it to reuse the seal but it got caught on the threads anyway, and it was too fiddly not to. When I refitted it, I did the seal as the last step and you can compress it oval a bit to get it over the cables and threads.

Sealant was just regular RTV. You barely need any at all. I made a little tool to spread a little 1mm wide blob. The first time I fitted it I put so much on it became the biggest part of the job to take it all off again.

[jeff-jordan]

...
I think I am seeing there two 'triangles of death'.

I think two of your magnets have begun to lift, probably due to rust behind the magnets. ...

These "triangles of death" that you seem to have spotted are not rust related (I checked every single magnet, no rust underneath).

I'm fairly certain to know what caused these "kisses" from magnets and stator, as I remember it well and it worried me somehow.
In fact that's where the idea came from to add a temperature sensor to the motor.

In late summer 2023 I drove more than 25km with pumped up current (155A line current) and hot weather.
The motor really got hot and at the end of the trip I heard a "zing zing" at every turn of the wheel.

After the engine had cooled down and avoiding such long high current stints since, I never heard the "zing-zing" again .

When I get my wheel back (today it's in the workshop for the tire change), I'm going to measure the magnetic flux with my gaussmeter, just to evaluate if the magnets in question are affected.

[bob2.0]

I only had obvious rust on two of the magnets (as you can find in the earlier thread).

Most of the rest were also terribly rusted, but outside looked as clean as yours.

There's no other reason for them to lift.

I used a simple 5mm wide tipped flat bladed screwdriver and tapped it very gently into the gap. This should have no effect on properly glued magnets, but will work its way in if they are rusted. Just strike the screwdriver end lightly with a small pin hammer, you will tell from the sound if it is a 'clunk' solid, or a softer noise.

Of course I cannot say for sure it is this. But it is curious how yours are two magnets spaced apart by one, this was exactly how the worst two in my own motor presented. I guess it is something about how condensate forms in the motor.

The worst that could happen is you break them off, and then you can glue on replacement thinner magnets (2mm). The middling result is that they come off and you find no rust underneath, ok, great, sand them down a bit on the backside and glue them back in, you can then get them properly flat again.