1954 Greenie Motor Just humms

[ERLover]

Nephews SS 54 Greenie motor took a dump this summer. I picked him up a bargain Grayling HS.
Now I want to redo the motor on the Greenie for my self. Where do I start? Or take it into a motor shop? Or an Ebay one? I want to be cost effective.
I am mechanical inclined, but not real great on electrics with out guidance here.

[ERLover]

I just checked EBay, I see $225 for a 1 1/8 HP motor is the going price.
I can get a whole SS for that on CL around here in prudent time

[BuckeyeDennis]

Sounds like you probably have a start-circuit problem. Capacitor, or more likely start relay/contacts. Either way, 20 bucks would be my guess for ballpark parts cost.

I've had a '58 DeWalt RAS motor apart, but never needed to crack open a SS motor. JPG probably has the wiring diagram permanantly etched in his brain.

[ERLover]

Sounds like you probably have a start-circuit problem. Capacitor, or more likely start relay/contacts. Either way, 20 bucks would be my guess for ballpark parts cost.

I've had a '58 DeWalt RAS motor apart, but never needed to crack open a SS motor. JPG probably has the wiring diagram permanantly etched in his brain.

I will start buy getting a new capacitor unless advised other wise here, seems like the cheapest and easiest try. I will post more when I bring it here to moms next week and delve into it and my testers with guidance here.

[beeg]

I will start buy getting a new capacitor unless advised other wise here, ...

Out of 100's of "replace the capacitor". 2 or 3 three capacitors were the problem.

[JPG]

Belay getting a start capacitor until you have determined it is needed.

The most likely culprit is the start switch.

The start circuit is simply the start winding in series with the switch and capacitor. The order does not matter as long as all three are in series.

One end of the start winding is likely internally connected to the run windings. The other end of the start circuit connects to the other end of the run windings but is likely not internal to the windings.

If you can carefully open it up and check for continuity of the switch(closed/made) you may discover it is open. That coincides with the hum/no run symptom.

P.S. a disconnected wire in the series circuit will also cause the same symptom(which you got).

[ERLover]

Belay getting a start capacitor until you have determined it is needed.

The most likely culprit is the start switch.

The start circuit is simply the start winding in series with the switch and capacitor. The order does not matter as long as all three are in series.

One end of the start winding is likely internally connected to the run windings. The other end of the start circuit connects to the other end of the run windings but is likely not internal to the windings.

If you can carefully open it up and check for continuity of the switch(closed/made) you may discover it is open. That coincides with the hum/no run symptom.



P.S. a disconnected wire in the series circuit will also cause the same symptom(which you got).

Say What??? Greek to me!!!!
Start switch?? on the HS or in the motor??
JPG I am good with electricity, when talking 120/240 volts in a house/commercial, but with motors I am Bob, taking baby steps, with the fish in the bowl.
We will take up this when I get it home in a week/weak and we can walk through/threw it in hand, step by step. Thanks, but with this I will need baby steps with motor in hand. I should have waited to/two/too then to post this, I knew/new better, but emotions got me.

[BuckeyeDennis]

Belay getting a start capacitor until you have determined it is needed.

The most likely culprit is the start switch.

The start circuit is simply the start winding in series with the switch and capacitor. The order does not matter as long as all three are in series.

One end of the start winding is likely internally connected to the run windings. The other end of the start circuit connects to the other end of the run windings but is likely not internal to the windings.

If you can carefully open it up and check for continuity of the switch(closed/made) you may discover it is open. That coincides with the hum/no run symptom.



P.S. a disconnected wire in the series circuit will also cause the same symptom(which you got).

Say What??? Greek to me!!!!
Start switch?? on the HS or in the motor??
JPG I am good with electricity, when talking 120/240 volts in a house/commercial, but with motors I am Bob, taking baby steps, with the fish in the bowl.
We will take up this when I get it home in a week/weak and we can walk through/threw it in hand, step by step. Thanks, but with this I will need baby steps with motor in hand. I should have waited to/two/too then to post this, I knew/new better, but emotions got me.

Electric motors aren't terribly complicated, but there are a bunch of different types. The type in a conventional Shopsmith is a capacitor-start induction motor. If you want to do a bit of homework, this article has a good overview of different types of single-phase induction motors. It should answer your most questions about the where & why of the start-circuit components.

[everettdavis]

This will be an oversimplification electrically, but the concept is what you seem to need to grasp.

The Start switch (Start Relay if you will) generally refers to a rotating spring-loaded mechanism at the end of the motor inside or outside the bell housing that when not spinning has a set of normally closed contacts that provides a complete circuit to the start windings of the motor.

If it is outside, you can (WHEN UNPLUGGED) remove a cover and service that mechanism, without having to take off the end bell (flange as some call them) of the motor.

The start windings have the ability to get the motor spinning by overcoming the weight of the mechanism that is not spinning, however, it lacks the ability to get the motor up to full running speed.

Once the shaft starts rotation, the spinning force of the start mechanism quickly overcomes the spring pressure that kept the normally closed contacts together, disconnecting the start circuit, on one side and connecting a set of contacts on the other side to the run windings, which brings the motor up to full running speed.

The centrifugal force of the now running motor is sufficient to keep the start switch's contacts in contact with the contacts that connected the run windings, and the motor continues to run until you switch it off by the power switch etc.,

You will hear the motor slow down, then when spinning slows sufficiently you will hear a click (Those springs just overcame the centrifugal force and closed back to the normally closed contacts) but the power switch is off an nothing happens.

Additionally the start capacitor is connected in the normally closed position (motor not spinning) to give a boost to the startup of the motor to help boost that speed quickly, and reduce the start current.

As soon as the motor starts, the start windings and that start capacitor are switched out of the circuit.

Think of the start switch as a mechanical relay where the coil of the relay that would overcome the relay's spring is replaced by the mechanical rotation to overcome the spring.

There are other ways of doing start circuits on different motors, even with an external start relay. Shopsmith has used several brands of motors through the years, and you will find several methods those manufacturers used for their motors.

The contacts of the start switch mechanism can be cleaned with a point file that you can find at any auto store. Older cars and even lawn mowers used points (opposed to electronic ignition) which would pit and corrode and need to be filed to clean them so they would work.

For those more experienced with that, the points mounted to a plate that could move back and forth connected to a set of spring weights that would move the plate when the rotor shaft of the distributor was spinning, somewhat like the start switch (relay) in the electric motor.

It was called mechanical advance mechanism, and like in an electric motor was a key component in the starting of a gasoline engine that was not spinning. In this application they only used one set of contacts because the plate moved the advance.

In an electric motor it really is more an start relay because it uses a normally closed set of contacts to start, and moves to a normally open set of contacts when sufficient movement by centrifugal force has occurred.

All that to say this: Dirt, sawdust and other gunk can mechanically interfere with the movement of the start relay on your motor even with good contacts. You can clean out the gunk, free up the movement, and clean the contacts, and likely restore the start circuit function.

I would only replace the start capacitor if it is visibly leaking, before you do the other maintenance to the start relay mechanism, or replace the external start relay if it has one of those. Generally those are not very friendly to being opened and serviced; that said, I have seen some that were made to.

Everett

[everettdavis]

I have received two PM's and two emails already.

I did say oversimplification..... some motors have the run windings connected, and the start relay keeps the start windings in the circuit (with the start capacitor) to get the motor spinning, then drops out when up to speed, leaving the run windings alone to keep the motor running at speed.

That can account for the hum one hears as the motor, devoid of the start circuit being added, cannot overcome the mechanical force needed to start rotation, meaning there are only one set of contacts that need cleaning - those that are (or should be) normally closed when the motor is not spinning...

And yes to my ER buddy (not 10ER) Emergency Room buddy, you could say it was something like a defibrillator to get the heart pumping...

Just remember - CLEAR! Work on it with no power connected, or you may need my buddy on standby....