Which bearings to check - Intermittent rough sound

[epodietz]

Bill thx for the tips. Yes it's an Emerson.

[JPG]

Not sure why I didn't find snap ring pliers on my first google search. Turns out I already have some 90 degree needle nose pliers that might do the trick. I like Anderson's bored board, gonna give that a go.

Yes, I s/b saying 'fan sheave' not 'motor sheave'.

I doubt the needle nose plier tips will be small enough.

That's ok, the fan sheave is half of the motor pulley.

[DLB]

Important Note: Don't let it go more than a couple of seconds with power applied if it's not starting up. These motors draw very high current when RPM is low, and it is enough current to burn out the windings quickly.

I don't see any sign of anything wrong at the sheave end.

Can you inspect the mechanical part of the start switch through the vent holes at the 'rear' (non-shaft end) of the motor? Only way I can see it relating to all symptoms is the mechanical portion coming apart and jamming or hitting things. You should see coil springs, one on each side, maybe 1/4 inch or so in diameter and 1-1/4 long. The springs should be firmly in place and look the same on both sides. If it has mechanically failed you'll probably see something out of place. Slowly rotate the shaft while looking.

- David

[JPG]

A couple of 'comments'.

The 'sleeve' is the newer thick one. The 'original' that tended to bury itself into the fan sheave was much thinner.

There is much dust inside the motor. Handling the motor has likely caused some of that dust to get into the start switch contacts preventing them from 'making'.

Also there is an access hole(other than the louvre vent) for getting to that set screw.

That set screw MUST be torqued firmly so as to prevent it coming loose.

Try banging with a nylon tip hammer to hopefully dislodge the speck of dust in the contacts.

Congratulations, you have gone from noisey to won't start!

Fear not we shall overcome all!!!

[epodietz]

Thanks again for the tips. The springs are in place. Nothing looking out of place/broken.

If the centrifugal switch is funky, as Bill suggested, I wonder if my blowing out the motor w/forced air might have caused contacts on that switch (or elsewhere) to get funky. There was a "fair" amount of dust in the motor although it wasn't horrible.

This morning, just on a whim, I turned the motor over, shook it a bit (nothing sounded loose), and blew some more air through it and got a little more dust out. I switched it on & voila, runs beautifully! Repeated on/off cycle several times. I feel better!

The shaft rotates cleanly, no in/out motion.

My question now, before I start thinking about reassembly, is about the spacer. I tried to get it off the shaft w/some hook tools, but it doesn't want to come. I would just as soon leave it in place as long as it isn't worn down. It looks good to me, but it's the only one I've ever seen.

I am beginning to wonder if the squeaking I heard when I first had the motor out and by itself was entirely due to dust...

[epodietz]

I just saw the latest post about the contacts and dust. Sounds like dust was the problem w/the switch. And that's good to hear regarding the sleeve - that it is the new type.

[JPG]

Do not sweat the spacer, it looks fine(and does not provide a handle for getting it off).

When reassembling, make sure the key is inserted all the way in so the set screw will retain it.

Knocking off any rough edges would be good.(shaft groove/key).

Before putting the floating sheave etc. on, oil shaft and sheave bore liberally.

[wa2crk]

Yeah!!! Use the oil like someone else is paying for it!!!
Bill V

[epodietz]

Well I got everything back together. Did some work on the bandsaw, then started to rough out a Cherry Bowl on the lathe. And then I heard some strange sounds. And now the headstock binds, then rotates freely for a while then binds. Time to open her up again...

I did test the motor by itself before putting it back into the headstock, and it seemed to run well, so i suspect the problem is somewhere else, which did not reveal itself when I had it open the first time. To be continued..

[epodietz]

Well I opened it up again and the motor is squeaking once more. Time for a bearing replacement it seems. The motor is an Emerson. I do have a set of bearings from J Anderson. I would very much appreciate any tips! Thx, eric