Dismantling and repairing the motor :o

[bob2.0]

I will give you my story for today.

I am mildly surprised how easily you have taken this motor apart in the past without the snags I have had, or maybe you have had them and you are better engineers than me (I am sure of it!).

I pulled the second plate off its bearing, it came of quite easily after I modified a small puller I have by extending the arm lengths.

But with this 2.0 the cables come out of the axle, and I had difficulty pulling the shaft seal off the wires and the axle where it is quite thick together.

Ideally, you'd remove the shaft seal and it can then easily distort to remove and refit. But it had hardened, I could not remove it from the top. So I dragged the seal over the threads of the axle and caused harm to the seal. Ouch. Which is very annoying.

I then realised the shaft seal on the other side should have a spring retainer, which had broken off a long while ago, judging from the fact that I found it had fallen on the floor in a corroded state. This might explain the elevated corrosion around the bearing on that side.

I would be happy to replace the shaft seals, but what are they? One I measured as 54mm diameter, the other is 50mm. I could not pull them out with a screwdriver (not without damaging them) as they seem quite hard, I will have to knock them out. But I can't do that until I have replacements. ... I guess they are just standard shaft seals with gaiter springs?

FWIW, on this 2.0 the bearing on the cable-side is a 6007, and it is a 6205 on the other side. I might replace them for ones with better sealing (to compensate for the shaft seal damage), but TBH they look OK, do not feel worn, are not leaking and seem to have prevented any ingress of water, if there had been any.

Tip; (this is to remind me in the future because I will forget and need to read this again!) you can tape up the axle thread, and maybe even lube it, before pulling the shaft seal over it, that way it will slide off without damage.

EDIT .. I forgot that shaft seals are always marked on the outer part, but without my glasses I didn't spot it first time.

Answer; one is 35 55 7, the other is 25 50 7.

[bob2.0]

I had a few thoughts on how to treat these laminations and magnets. Obviously, the first step is to sand things down and remove dirt and rust.

But after that, I had an idea of using the old machinists' trick of using camphor tablets, which leaves a molecular layer of film of camphor oil on all the tools in your toolbox as it sublimates, and stops them rusting.

I was not keen to leave a lump of camphor in the motor, because it does oxidise over time.

So I asked chatGPT what would replace camphor, and it explained to me there is a class of corrosion inhibitors now called VCIs, which do exactly that. They can evaporate and leave a film over everything, and work best in enclosed volumes (of which a hub motor is a perfect case, it should be sealed).

So I am currently exploring VCIs to use on the laminations, and just put a light coating on the magnets.

Is this a subject that has come up elsewhere on this forum, in other makes/etc, this concept to use VCIs in hub motors?

chatGPT offered up this list, based on my request for a solid or semi-solid application and not too expensive.

and I further asked for a comparison and recommendation.

[bob2.0]

The damaged seal is a frustration. It only just occurred to me that the bearing has to be mounted before the wiring is fixed and the seal has to go on after that. So it will always be a tight fit getting the seal on and off.

The bearing is OK, just as well because to remove it, the cables have to be disconnected from the copper bundles, and then resealed after removal and refitting. That's a PITA job.

[bob2.0]

Would anyone have a view on what this is?

I think it is just some careless drips of sealant during manufacture.

But the other thought was that this is what the start of a short circuit looks like, and it is melted wire enamel?

Have you seen like this on yours?

[jeff-jordan]

For me, it doesn't look like molten wire enamel.
Probably some careless drops of sealing, or some remainders (molten fluxing agent and dropped tin solder ?) from the soldering job.

Can you wipe/scratch that (is it soft?) off, without the use of any chemicals, and have a closer look with a watchmaker's magnifying glass at the wire?

[bob2.0]

For me, it doesn't look like molten wire enamel.
Probably some careless drops of sealing, or some remainders (molten fluxing agent and dropped tin solder ?) from the soldering job.

Can you wipe/scratch that (is it soft?) off, without the use of any chemicals, and have a closer look with a watchmaker's magnifying glass at the wire?

Thanks for that opinion, which was my thought too.

It is very hard, won't wipe off easily, I'd not put more mechanical force on it.

I do have a 'pencil' gas torch, small hand held thing, low power, I was thinking just to heat it up very locally see if it melts and wipes off. Do you think it is worth a test, or just leave it?

[MEroller]

I would just leave it alone, it does not look charred or anything of that sort.

[jeff-jordan]

I would just leave it alone, it does not look charred or anything of that sort.

I agree, simply leave it as it is.
It doesn't look as a problem.

Even a simple, tiny gas torch might easily melt the enamel of the copper wires.

[Raulpahon]

Hello! Is it possible to convert a MAR motor with an encoder to Hall sensors? Do you have any references for Hall sensor parts?

[TwisterMax]

Hello! Is it possible to convert a MAR motor with an encoder to Hall sensors? Do you have any references for Hall sensor parts?

Why don't you like your encoder-? Remember If you change to hall-sensors, you have to change Controller too.