Motor shaft extension

[Masterjuggler]

I picked up a cheap 3 phase 2hp motor, and it works perfectly, but the shaft has been sawed off at about 1 inch for some reason. I don't have an immediate need for the motor, but eventually I think I'll use it in a table saw build. Does anyone have any recommendations for the best way to extend the shaft if need be for a pulley?

I'm thinking I'll do something with drilling and tapping the end to thread in an extension with loctite. I figure this would work for a table saw where the motor only needs to turn in one direction, but I'm not sure what I'd do if I want to use the motor in a reversible application.

 

[Dave Smith]

1 inch should be long enough for most pulley mounting. if not then bore out a larger shaft to fit over the motor shaft and put a flat on motor shaft and use 2 set screws to hold it. turn the new shaft to pulley ID. if your motor is a 3450 speed then this would not be the best solution. you could drill and tap the motor shaft and then use a socket head bolt head as a nub to slightly extend shaft. I would rather just make my pulley to work on the short shaft. Dave

 

[Winegrower]

I did this same thing by making a sleeve to fit over the old shaft and new shaft, coupling them together. I cut a keyway in the sleeve and in the new shaft. Fortunately the old short shaft already had a keyway.

 

[benmychree]

I would make an oversize shaft with a pilot diameter to fit into a small bored hole in the motor shaft and make a J weld prep on the two halves, and weld it on, then machine to final diameter and cut a keyway.

 

[Masterjuggler]

Good suggestions guys, thanks. I'm not exactly sure how I'll use the motor yet so I've got time to mull it over. I'll probably just make do with the stubby shaft, especially if I make the pulley myself which is entirely likely. Short of that, I like the idea of making an oversize extension sleeve for it. I don't have a good way of cutting a square keyway slot so I'd probably drill between the shaft and the sleeve for a round key.

 

[matthewsx]

Make due with it like it is.

Chances of introducing wobble are fairly high and you should be able to buy or make a pulley that will fit.

John