Glue for a 12v electric motor.

[Quandary]

I am persevering (foolishly, I know, but this years budget is going to Flexofold and Planar) in my attempt to repair the windlass, gears and bearings seem okay despite the crud around them , though I am not so sure about the electrically operated freefall lever which moves to disconnect the drive shaft, I am hoping to be able to dispense with this.
The motor has not fared so well, The brushes look okay though the commutator is discoloured but there are 4 separate heavy magnet segments around the windings, three of which are sitting tight to the motor case, the fourth is cuddling up to its neighbour despite the magnetic force holding it to the casing and each time I position it it just slides around to close the gap with the next segment.
I presume the three that do not move are glued to the casing and that the glue should be conductive?
A google search reveals specialist conductive glues for electric motors including some by Loctite but these are not marketed to the DIY trade, any suggestions about what might be more readily available to do the job?
Or could I bodge it by putting a couple of small self tappers through the housing and in to the loose magnet?

 

[neil_s]

I don't think you need conductive glue - as in electrically conductive. The casing of the motor needs to conduct the lines of magnetic force between the magnets. To help this, the gap between magnet and case needs to be as small as possible. So, I think you need a thin runny glue, like Loctite, perhaps?

 

[lw395]

I agree the glue need not be conductive.
The gap should be small, but as there is a significant gap between the magnet and the armature, trying to make the glue line really thin will not have much effect.
I would probably try epoxy.

 

[Heckler]

I am persevering (foolishly, I know, but this years budget is going to Flexofold and Planar) in my attempt to repair the windlass, gears and bearings seem okay despite the crud around them , though I am not so sure about the electrically operated freefall lever which moves to disconnect the drive shaft, I am hoping to be able to dispense with this.
The motor has not fared so well, The brushes look okay though the commutator is discoloured but there are 4 separate heavy magnet segments around the windings, three of which are sitting tight to the motor case, the fourth is cuddling up to its neighbour despite the magnetic force holding it to the casing and each time I position it it just slides around to close the gap with the next segment.
I presume the three that do not move are glued to the casing and that the glue should be conductive?
A google search reveals specialist conductive glues for electric motors including some by Loctite but these are not marketed to the DIY trade, any suggestions about what might be more readily available to do the job?
Or could I bodge it by putting a couple of small self tappers through the housing and in to the loose magnet?

In the olden days mr lucas used to use counter sunk screws to hold the bits in place. I would scrupulously clean everything up and glue the thing in place with araldite. Use clamps to overcome the magnetism. Then drill and tap and fit a la mr lucas

 

[RichardS]

I don't think you need conductive glue - as in electrically conductive. The casing of the motor needs to conduct the lines of magnetic force between the magnets. To help this, the gap between magnet and case needs to be as small as possible. So, I think you need a thin runny glue, like Loctite, perhaps?

I agree. I've never come across conductive glue in any electrical motor or device that I have ever stripped down.

You would probably be best to use an epoxy like JB Weld or Araldite or similar, although the high-temp stability of the JB versions would probably be helpful.

Richard

 

[Poignard]

I would try CT1.

 

[Quandary]

I have both JB marineweld and CT1, I think I might try the former this time. To position it I was going to use a couple of temporary spacers in the gaps and then depend on the magnetism to hold it tight to the case while it set.
Thinking further, if I was to make the spacers from bits of plastic chopping board (I keep these when they are discarded by cook as they can be worked like wood and are water resistant and insulating) I could just leave them in place to resist movement when the motor rotates, or is that silly?
The Marineweld is also being used to build up the corroded bits of the alloy casing.
I suspect this windlass may never go back but I am learning a lot from the rebuild.
Again, my thanks for the advice.

 

[Lon nan Gruagach]

Just agreeing with most of the above but...
Regards air gap in a magnetic circuit. its the total length of air gap that is the problem, so it dosent matter if its in front of or behind the magnet, what is important though is the clearance for the spinny bit in the middle.
Also assume that it is going to get hot, not just a bit warm,so high temperature stability is essential.