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Old May 03, 2012, 03:14 AM
yergacheffe is offline
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United States, CA, Cupertino
Joined May 2012
7 Posts
Originally Posted by jackerbes View Post
The reason for all of those spacers is to get the assembly right when they are taking parts out of bins and hoppers in a mass production shop. It you fit the shaft yourself you can usually eliminate most of those unless they serve a purpose.
I figured it was something like that. I'm guessing the purpose of the washers is to minimize play in the event that bearing #1 slips out?

Those threads are pretty much all you need to know to get those apart. The shaft is a moderate force press fit into the magnet housing and held there by a grub screw bearing on a flat on the shaft. The shaft should slide out of the bearing races with light pulling forces. But the snap ring grooves will snag and then more force is needed. And it is hard to restrain the back half (stator and bearing tube) and get a pulling force on the magnet housing.

I use socket wrenches, small pieces of metal tubing, etc. (large enough to take the 4mm shaft), to press the shaft into and through the magnet housing. The tube has to be used to localize the pressing forces to right around the shaft or the magnet housing will be deformed. Aluminum, copper, or brass tubes or pipes are best as you don't have to fight the magnets to use them inside the housing.

I do a lot of my pressing in the horizontal plane with a bench vise. And I'll use punches, smaller shafts, and hammers to make things move when I have to. If the bearings are already shot, I don't worry about damaging them any worse.
Yeah I've been using a 1/2" diameter piece of pvc pipe that's longer than the shaft pressed against the front (propeller) side to help coax the shaft out. This way only a short length of shaft has to bear the strain of being squeezed in the vise. I had problems doing it the other way around, with the pvc pipe on the back end of the housing. My shaft was bending as I compressed the vise due to its full length providing a better torque arm to bend itself with. Of course, this shouldn't have happened to begin with if I hadn't been so eager to fly that I skipped over cutting the shafts down to a proper length.

So now that I've got the shaft flush against the housing, I need to find a tube that's <4mm to push the final bit of shaft out.

Friendly advice, go to the Advanced posting mode and use the Manage Attachments menu to upload your images to the servers here. That means they will display as thumbnails until click on and also be here forever to help others.
Noted, I've gone ahead and reuploaded my images in my previous post as well.
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