06-08-2012, 07:43 PM
(06-03-2012, 09:41 PM)Tony Wells Wrote: The second shop I worked in did all the machine work for a nearby electric motor shop, so we got a lot of metalizing and shaft repair /replacement. If you wanted, for any reason, to maintain the original shaft, they are pressed in and can be removed and replaced with a newly made shaft of whatever size you want. Otherwise, a 4 jaw with pads, and a good bearing center is sufficient to turn it down. Watch that you don't reduce the seal area if the motor has a live seal on the shaft, and be sure to leave a 1/32" minimum corner radius where you shoulder out. And you may have to recut the keyway, or at least need to make a non-standard key.
If possible, boring the sheave/pulley would be preferable.
I have made pretzels out of perfectly good 1-1/2 diameter shafting by trying to press out the shaft from rotors. The shaft is pressed into a series of thin metal plates with an aluminium cages cast on the end, when you try to press out the steel shaft, the aluminium deflects and the thin plates wedge slightly side ways, then it gets really hard to press. A Bue gets built up on the shaft and wedges tight.
Turning down the shaft by gripping in chuck and supporting with ball bearing centre should work out just fine. Follow that with recutting a new key slot.
Walter
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