Ok, so I went out and spent $50 bucks at harbor freight for a bearing
puller. Nice enough set, use the big puller for these bearings and not
the small one.
First I practiced on an old motor shaft. Rear bearing is simple to
remove, tapping on the new one with a socket just a bit smaller than the
inside race got it on with no problems.
I could not remove the blade hub from the bottom: Putting bolts in the
hole all the way simply results in the bolts collapsing with the puller.
Heat didn't help, so I gave up for now. Maybe I need a tungsten rod or
something like that but the forces here are simply insane.
Next up was the real motor shaft. Back bearing came off pretty easily
but the front one was another matter. First the bearing exploded: It
broke apart and the outer race cracked. So much for that. Getting the
inner ring off took heat, pressure, and whacking away at the puller with
a hammer but finally it started to move and came off. I cleaned up the
shaft, used the old inner race as my spacer with some 3/4 washers and a
21mm socket to tap on the new bearing (once again only pressure was on
the inner race) and I think I drove it on a tiny bit too far. Will see
what that does to the motor alignment.
Next job was to fix the magnet. Before I started gluing I noticed that
it was impossible to really hold the magnet in place because it pushed
away from the other magnet in line with it, and it always wanted to
smack into the magnet on the other side. So after a moment of though I
got some 1/2 playwood, and started making jigs.
First I cut a strip a bit wider than the normal separation amount of the
magnets. Then I used the grinder to make a perfect snug fit so the wood
would just go down the side. Then I did the other side, now I have a set
of guides for the new magnet.
But even that is not enough as the magnet pushes away from its neighbor.
So I made a second spacer that went across the inside diameter of the
motor magnets. Just barely fits. Now I'm ready: I cured up some JB weld,
covered a good bit of the magnet face and the inside metal face, put in
my two side jigs, put in the magnet (I marked it, also it's easy to see
the side that butted the other magnet as it's pretty clean), then drove
in the center spacer, made sure everything was as aligned as I could,
and am leaving it for a couple of hours to cure.
Hopefully this works. If so I'll assemble it and give it a try on a
small 12 supply. Should spin right up.
Next I am going to need some sort of end seal, as I didn't see one on
this motor, and something's got to keep junk from getting in there. I am
using sealed bearings this time as opposed to the stock open ones with
metal shields, we'll see what happens.
Any other ideas on getting these hubs off, or should I just cut them
lengthwise with my cutting wheel?
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