Motor Problem AGAIN

[Chasboy1]

HI Folks, a number of you helped me in my disassembly of my power head and motor on my 1954 SS. I replaced the bearings and spacer in the motor and all seemed great until 10 minutes ago. As I was starting a new pen, I stopped to see how my cuts were going. When I tried to restart I got a humming sound and no motion. I tried moving everything by hand, including changing the speed but to no avail.
I removed the motor cover from the end and freed up the motor belt.
After that I tried power again and all the motor did was hum, then start to run at about 50 rpm, with a background humming noise.
Does anyone have any input?

Am I going to waste more time, and/or should I get a new motor? The one from the factory is over $400, but I have concerns about another used one.
Thanks!

[dusty]

Don't give up easily. Take off the motor belt and attempt to run the motor.

Don't change the speed setting without the drive shaft turning (use a sanding disk).

You said you had to free up the belt. Please - more detail. If the belt was trapped in the sheave that is likely why the motor was humming and not turning.

[br549]

I feel your frustration. I have had mine suddenly do something similar a few times. It would be working fine, then suddenly not want to start and just hum. In my case, it usually turned out to be sawdust build-up in the motor interfering with the centrifugal switch. And once the button bearing on the control sheave failed and gave me similar slow rpms and strange noises.

Before damaging the motor by letting it hum, take a deep breath, and do some more investigating.

The experts here will help you get thru this, again.

[Chasboy1]

I removed the motor belt and thats when the motor moved slowly. I never change the speed unless the shafts are moving, or the belt is not in place.

[DLB]

Try spinning it by hand with the belt off and no power. It should spin pretty freely and quietly. Was there any visible smoke or strong smell at any point when it was powered and not turning?

- David

[JPG]

Start switch! May require taking the motor apart. Some sharp rapping(with a NON-metallic hammer) MAY knock whatever is preventing the contacts from making loose before disassembly.

[Chasboy1]

which part is the start switch? Yes the motor moves freely. Last time I tried it, it tripped a GF outlet and only hummed.

[br549]

Depending on the brand of your motor, it may look different, but here is what my 1 1/8 hp GE motor's looks like:

P5010335.JPG (184.37 KiB) Viewed 1553 times

P5051431resized.jpg (212.41 KiB) Viewed 1553 times

And here is a link to a thread about the subject (and at least one other link within it)
viewtopic.php?f=10&t=17624

[Chasboy1]

I should have mentioned its a Franklin 3/4 hp motor

[JPG]

Regardless of the brand, the start switch will consist of contact points and a centrifugally weighted mechanism that moves half of a contact pair.