Shopsmith Forums

I have not seen the inside of a(my) A O Smith motor either, but offer the following after seeing the two pix above.

The start switch is in the end(as shown in Jsburger's pix) and has a rub 'plate' that is pushed against by the actuator that rotates on the shaft.

Pushing on that plate should cause the switch contacts to open.

The actuator rides on the shaft. I believe the black(bakelite?) part is what gets pushed out to press against the plate. The metal part with brass weights should push the black part out when the weights are flung outward by centrifugal force as the shaft gets up to speed.

There should also be a spring of some sort that causes the weights to be retracted when the motor is stopped. The actuator apparently is not exhibiting the pushing of the black part. The weights are either being restricted from being 'flung' or are not linked to the black part correctly.

So cast your eyes/camera into the interior of the weight 'housing'.

Thanks jpg.

There is a little springy part on that bakelight part. What was happening is the centrifical switch was getting stuck in that metal part due to slight movement in the shaft. I tightened the motor bolts down to eliminate the slop and got the centrifical switch aligned properly and it is running for the most part.

If I turn it on and off ten times, one of those times I have to give the shaft a little turn to get the starter coils to engage.

Now! On to that control cam

richardrouse wrote:You are right dusty! It kind of floats there.

It's real finicky about the placement.

I had it running for a while in forward. Then, when I went to reverse it, the motor started bucking on the table.

Now, it just buzzes. I;m guessing that the centerfugal switch isn't tripping the starter armature any more.

Did you let the motor come to a stop before you put it in reverse?

Just to be clear, when the motor is not running the start winding contact is closed placing the start winding in the circuit. At some predetermined speed the centrifugal mechanism actuates allowing the contact to open and removing the start winding from the circuit. If the motor buzzes on startup then the start winding contact is not closed or the capacitor is bad. Turn the motor on and spin the shaft by hand. If it takes off and runs then the motor is OK and you have one of the above problems.

JPG wrote:I have not seen the inside of a(my) A O Smith motor either, but offer the following after seeing the two pix above.

The start switch is in the end(as shown in Jsburger's pix) and has a rub 'plate' that is pushed against by the actuator that rotates on the shaft.

Pushing on that plate should cause the switch contacts to open.

The actuator rides on the shaft. I believe the black(bakelite?) part is what gets pushed out to press against the plate. The metal part with brass weights should push the black part out when the weights are flung outward by centrifugal force as the shaft gets up to speed.

There should also be a spring of some sort that causes the weights to be retracted when the motor is stopped. The actuator apparently is not exhibiting the pushing of the black part. The weights are either being restricted from being 'flung' or are not linked to the black part correctly.

So cast your eyes/camera into the interior of the weight 'housing'.

Actually (in the A O Smith 1/2HP motor) the actuator pushes on the rub plate to keep the contact closed so the start winding is in the circuit at startup. When the actuator retracts due to centrifugal force the contact opens due to the spring action of the hard copper/phosphor-bronze or whatever metal the contact mechanism is made from.

As I said before the 10ER is quiet enough that you can actually hear the centrifugal mechanism actuating on start up and shut down. You can also feel it if you put your hand on the motor.

jsburger wrote:

JPG wrote:I have not seen the inside of a(my) A O Smith motor either, but offer the following after seeing the two pix above.

The start switch is in the end(as shown in Jsburger's pix) and has a rub 'plate' that is pushed against by the actuator that rotates on the shaft.

Pushing on that plate should cause the switch contacts to open.

The actuator rides on the shaft. I believe the black(bakelite?) part is what gets pushed out to press against the plate. The metal part with brass weights should push the black part out when the weights are flung outward by centrifugal force as the shaft gets up to speed.

There should also be a spring of some sort that causes the weights to be retracted when the motor is stopped. The actuator apparently is not exhibiting the pushing of the black part. The weights are either being restricted from being 'flung' or are not linked to the black part correctly.

So cast your eyes/camera into the interior of the weight 'housing'.

Actually (in the A O Smith 1/2HP motor) the actuator pushes on the rub plate to keep the contact closed so the start winding is in the circuit at startup. When the actuator retracts due to centrifugal force the contact opens due to the spring action of the hard copper/phosphor-bronze or whatever metal the contact mechanism is made from.

As I said before the 10ER is quiet enough that you can actually hear the centrifugal mechanism actuating on start up and shut down. You can also feel it if you put your hand on the motor.

I should have realized that! The actuator does not wear against the switch rub plate when 'running', only during startup and stopping.

As for the 'reverse' while still coasting: if the start switch contacts are open, the motor will continue to run in the original direction. If the contacts have made, the armature will attempt to reverse. That could be a cause of 'bucking'.

P.S. The original M VII switch is a PITA intentionally. To reverse, you must first push stop, then push the other direction. That allows time for the motor to coast down. However those with quick fingers will quickly realize that it must actually stop in between(or at least close the start switch). The direction it runs is determined by the 'polarity' of the start windings at startup only.

I always let it stop before re-engaging the fwd or rev.

I can hear the clicking you are talking about when I turn the rotor by hand and when it coasts to a stop.

I'm going to replace the capacitor at any rate, already ordered from amazon.

Hopefully that will stop the occasional buzzing.

Attention to the start switch contacts etc. will likely be more successful.

JPG wrote:

jsburger wrote:

JPG wrote:I have not seen the inside of a(my) A O Smith motor either, but offer the following after seeing the two pix above.

The start switch is in the end(as shown in Jsburger's pix) and has a rub 'plate' that is pushed against by the actuator that rotates on the shaft.

Pushing on that plate should cause the switch contacts to open.

The actuator rides on the shaft. I believe the black(bakelite?) part is what gets pushed out to press against the plate. The metal part with brass weights should push the black part out when the weights are flung outward by centrifugal force as the shaft gets up to speed.

There should also be a spring of some sort that causes the weights to be retracted when the motor is stopped. The actuator apparently is not exhibiting the pushing of the black part. The weights are either being restricted from being 'flung' or are not linked to the black part correctly.

So cast your eyes/camera into the interior of the weight 'housing'.

Actually (in the A O Smith 1/2HP motor) the actuator pushes on the rub plate to keep the contact closed so the start winding is in the circuit at startup. When the actuator retracts due to centrifugal force the contact opens due to the spring action of the hard copper/phosphor-bronze or whatever metal the contact mechanism is made from.

As I said before the 10ER is quiet enough that you can actually hear the centrifugal mechanism actuating on start up and shut down. You can also feel it if you put your hand on the motor.

I should have realized that! The actuator does not wear against the switch rub plate when 'running', only during startup and stopping.

As for the 'reverse' while still coasting: if the start switch contacts are open, the motor will continue to run in the original direction. If the contacts have made, the armature will attempt to reverse. That could be a cause of 'bucking'.

P.S. The original M VII switch is a PITA intentionally. To reverse, you must first push stop, then push the other direction. That allows time for the motor to coast down. However those with quick fingers will quickly realize that it must actually stop in between(or at least close the start switch). The direction it runs is determined by the 'polarity' of the start windings at startup only.

Exactly!!!

Interestingly, look at the rub buttons on the rotor in my picture. They are worn at an angle as expected. However they look new. They are a kind of closed cell plastic foam (I think). They are NOT deteriorated at all after 60 years and feel like I think they should when new.

Could it be that the powers to be that think they know better than us banned some chemical that made this possible?

Sorry, make your own judgment.

I think so. That doesn't mean this is all bad.

richardrouse wrote:I always let it stop before re-engaging the fwd or rev.

I can hear the clicking you are talking about when I turn the rotor by hand and when it coasts to a stop.

I'm going to replace the capacitor at any rate, already ordered from amazon.

Hopefully that will stop the occasional buzzing.

You should not hear the clicking when you turn the rotor by hand. You can not turn the rotor fast enough by hand to actuate the centrifugal switch. That is unless something else is wrong. No springs or weights per JPG since you stated you took them off. If the weights are not there then the switch will not function as designed.

Thanks again for all the input guys! The clicking that I'm hearing is the armature of the start switch rising and falling against the black plate. Once the motor stars, the clicking stops. I assumed that the lack of click was when the centrifical switch had pulled away from the contacts of the starter switch.
Bear with me here guys I'm thinking through the problem in light of what I've read.

So, I can hear the clicking when I turn the rotor by hand and when it coasts to a stop .. Otherwise when its running I just get motor noise.
Unless I'm completely misunderstanding how the motor works,

While at rest the centrifical switch relaxes and allows the black rub plate to pass over the contacts of the starter. This closes the circuit on the starter windings for start . once the motor gets a run command, the rotor spins and at some speed the weights in the centrifical switch pulls the rub plate away from the starter and remove it from the circuit.

So, because when I turn the rotor by hand, I can hear the armature moving up and down.. That means that the starter is taken out of the circuit every fraction of a turn. ( that would be why I have to turn it by hand occasionally... To line the rub plate back up with the contacts of the starter).

Am I on the right path? If not slap me and reel me back in.

I'll have to snap a picture of it tomorrow to show you all what is there.
I'll get some video as well.

Question:
1) I should not hear any clicking when the motor is at rest because the rub plate should be in constant contact with the starter while the motor is at rest?

2) as far as checking the starter itself, I have placed my meter's probes across the solder joint and the lead that goes to the run switch.. I have continuity across those leads when the armature of the starter is closed.. Is there a way to check the windings? I've checked for ground faults on all of the leads and didn't have any.
Is there a better way to check the switch?