Yikes! Craftsman 100 Drill Press Help

[Modagger]

Greetings learned members of the fount of wisdom!

I come seeking guidance on where I messed up.

I picked up a Craftsman 100 drill press to restore for my brother. It was in good usable condition but I wanted to pretty it up. My first task was to disassemble the motor, (which ran smoothly with no noise or vibration). I wanted to degrease it, paint it and while I had it apart figured I would put new bearings in it.

As this is my first electric motor rebuild, I was very careful to mark every wire and where it came from.

New paint, new bearings, disassembled the governor, cleaned it and reassembled it. Got it all put back together and now it is making a noise that is coming from the terminal end.

When the terminal end is facing down, the noise is less pronounced.

My suspicion is that I messed up the governor, but after reassembling, it operated without restriction by hand.

Before I blindly go where no man, well actually I’m hoping at least one man has had this problem and is willing to fess up and share.

Be well
Jeff

 

[RTM]

Suggest you add CMan Drill Press to the title to get the attention of the right people.

¢¢

 

[nadogail]

Very possibly you may need to adjust the thrust clearance on the motor.

 

[FrankLee]

It sounds like the governor is hitting something, possibly a wire that is not tucked in enough.

You might be able to see something through the vent openings, but you're going to have to crack open the motor again. You don't need to remove the switch end frame from the stator at this point.

Because you dismantled the governor, please post a couple photos of the governor, in addition to a couple photos of the switch down through the stator.

 

[Modagger]

Here’s before and after of the governor. I’ll get a switch photo a bit later.

 

[Davefr]

It sounds like the rotor is not properly centered in the core of the stator and that throws off the alignment of the centrifical switch. Were there wavy or regular washers in the end bell(s) between outer rotor bearing surface and the end bell recess. They need to be there and in their original location(s) . Are you sure the new bearings are identical in size to the old ones?

Double check your centrifical switch seating, make sure wires are properly routed and make sure the end bells are fully seated with the case of the motor. End bells should be tightened gradually and equally in an opposing sequence. (like installing a wheel rim). The shaft should turn easily by hand and there should be no binding. (tiny alignment issues will cause problems.)

 

[Modagger]

It sounds like the rotor is not properly centered in the core of the stator and that throws off the alignment of the centrifical switch. Were there wavy or regular washers in the end bell(s) between outer rotor bearing surface and the end bell recess. They need to be there and in their original location(s) . Are you sure the new bearings are identical in size to the old ones?

Double check your centrifical switch seating, make sure wires are properly routed and make sure the end bells are fully seated with the case of the motor. End bells should be tightened gradually and equally in an opposing sequence. (like installing a wheel rim). The shaft should turn easily by hand and there should be no binding. (tiny alignment issues will cause problems.)

Davefr

The rotor spins freely by hand with no discernible binding. There was a spring washer on one end only, which I believe is correct. The bearings are correct replacements. On the terminal end, both old and new bearing sit low with nothing between the bearing and the end cap to account for the space. Also, both bearings go in and out of the race without binding.


I did use the opposing sequence when tightening.

Jeff

 

[Modagger]

I did notice during disassembly, the there were no spacers or insulating pieces between the switch and the end frame as in Jeff’s Shop motor rebuild video. The switch screwed directly into the end frame.

Also, I couldn’t see any places where it would seem that contact was being made. No paint missing, no wires chafed.

 

[FrankLee]

Here's a 115.19780 I had a while back. The date code was 3 58.

I see two differences between yours and mine.

1. Mine did have a fiber shield on the outboard side of the switch.
2. One wire from the thermal switch is routed differently.

These don't mean that yours is wrong. The owners manual does not show a fiber shield.

Your spring washer looks to be installed correctly.

The bearing number looks correct, but are they pressed on? Or loose?
I have bought those HCH bearings many times. I received some yesterday and expect some today. It is possible that one of yours is bad, but not likely.

There are two things I never do (ok, very rarely do) when dismantling a motor.
1) I do not dismantle the governor assembly and don't recommend it.
2) I do not remove wiring to the terminal bar unless to repair or replace.
Is the governor sleeve the same on both sides? I.e., is it upside down?

One other thing to check is that the end frames are fully seated onto the stator during assembly. A cocked end frame can do goofy things.

Many times when I have had issues with something, all it took was to dismantle and reassemble to resolve problems with no explanation as to why.

 

[Modagger]

Here's a 115.19780 I had a while back. The date code was 3 58.

I see two differences between yours and mine.

1. Mine did have a fiber shield on the outboard side of the switch.
2. One wire from the thermal switch is routed differently.

These don't mean that yours is wrong. The owners manual does not show a fiber shield.

Your spring washer looks to be installed correctly.

The bearing number looks correct, but are they pressed on? Or loose?
I have bought those HCH bearings many times. I received some yesterday and expect some today. It is possible that one of yours is bad, but not likely.

There are two things I never do (ok, rarely do) when dismantling a motor.
1) I do not dismantle the governor assembly.
2) I do not remove wiring to the terminal bar unless to repair or replace.
Is the governor sleeve the same on both sides? I.e., is it upside down?

One other thing to check is that the end frames are fully seated onto the stator during assembly. A cocked end frame can do goofy things.

Many times when I have had issues with something, all it took was to dismantle and reassemble to resolve problems with no explanation as to why.

FrankLee

I just finished an elimination experiment. I reinstalled the original bearings and ran jumpers between all of the appropriate wires just to eliminate any possibility that one of the external parts was vibrating and telegraphing towards the terminal end.

Result: same noise, so next I’ll reinstall the new bearings, then take the governor apart, verify it’s assembled correctly, or not, and reassemble. That may be difficult with fingers crossed on both hands.

I’m pretty sure I put it together the way it came apart. I took photos at each step.

The bearing on the terminal end goes on without persuasion. Other end needs a bit of help.

Also, there is no play when I try to move the rotor back and forth.

If this doesn’t work, I’ll ask my neighbor if he needs another anchor for his boat.

Jeff

 

[Davefr]

Davefr

The rotor spins freely by hand with no discernible binding. There was a spring washer on one end only, which I believe is correct. The bearings are correct replacements. On the terminal end, both old and new bearing sit low with nothing between the bearing and the end cap to account for the space. Also, both bearings go in and out of the race without binding.


I did use the opposing sequence when tightening.

Jeff

Jeff, the only other theory is that maybe the spring washer is making contact with the inner (ie spinning) portion of the bearing when that cap is tightened. Try removing the spring washer as a test and see if the noise goes away.

Could the rotor's fan have a blade that's bent?

 

[FrankLee]

Hmmm.

Do you see any evidence of scraping between the rotor and the stator? Or on the outside edge of the weight where it swings out? I.e., is the weight swinging out too far?

 

[Modagger]

Jeff, the only other theory is that maybe the spring washer is making contact with the inner (ie spinning) portion of the bearing when that cap is tightened. Try removing the spring washer as a test and see if the noise goes away.

Could the rotor's fan have a blade that's bent?

Good thought! I’ll remove the spring washer.

I don’t think it has any bent part. It worked fine without my intervention.

 

[Modagger]

Hmmm.

Do you see any evidence of scraping between the rotor and the stator? Or on the outside edge of the weight where it swings out? I.e., is the weight swinging out too far?

I’ll check those things during the next disassembly.

 

[Modagger]

Jeff, the only other theory is that maybe the spring washer is making contact with the inner (ie spinning) portion of the bearing when that cap is tightened. Try removing the spring washer as a test and see if the noise goes away.

Could the rotor's fan have a blade that's bent?

Not the spring washer, and no bent or broken blades.

 

[Modagger]

Hmmm.

Do you see any evidence of scraping between the rotor and the stator? Or on the outside edge of the weight where it swings out? I.e., is the weight swinging out too far?

No evidence of any interference between rotor and stator. Outside edges are untouched on the weights.

I took the governor apart and verified that it was reassembled correctly.

The only thing I see that looks like a rub point is on the switch. Does this look “normal”?

 

[FrankLee]

The only thing I see that looks like a rub point is on the switch. Does this look “normal”?

Yes, that's normal.

I'm wondering if the switch is opening, but the governor sleeve is not lifting off the switch completely.
Or, only one weight is swinging out or one weight is swing out more than the other.

Check my video in this post:
https://www.garagejournal.com/forum/threads/craftsman-drill-press.227480/page-138#post-11150184
You can see in my video how the gov sleeve is somewhat wobbly.

You might be able to see this on yours through the vents.

 

[Modagger]

Yes, that's normal.

I'm wondering if the switch is opening, but the governor sleeve is not lifting off the switch completely.
Or, only one weight is swinging out or one weight is swing out more than the other.

Check my video in this post:
https://www.garagejournal.com/forum/threads/craftsman-drill-press.227480/page-138#post-11150184
You can see in my video how the gov sleeve is somewhat wobbly.

You might be able to see this on yours through the vents.

At this point I’m wondering if I cleaned it too well. The governor sleeve was not operating on the shaft very smoothly. Now it moves through it’s trajectory with ease.

I’m going to reinstall the new bearings, make sure everything lines up squarely, and try to see the operation of the switch/governor.

Thanks everyone

Jeff

 

[Modagger]

Can someone print me up a certificate for completion of the “fix one, break two” class?

Now the vibration is gone and running smoothly. However…….., now it growls on startup and, wait for it…….., it randomly changes rotation direction with every different start. Have mercy!

 

[RTM]

randomly changes rotation direction with every different start. Have mercy!

If you were in software development, you'd call that a new feature.

 

[Modagger]

If you were in software development, you'd call that a new feature.

Hah!

 

[Modagger]

Does anyone have any thoughts as to what would make it growl and randomly change rotation direction?

 

[Cruzan80]

Probably something with the start winding. Which is directly related to the governer, as that helps it connect/disconnect. If the capacitor isn't connected, that would also prevent the start winding from energizing.

The start winding provides the extra "kick" in the correct direction to help it get up to speed. Otherwise, the rotor could have landed in between the run windings, and will go to whichever is closer/easier (hence the flipping direction).

 

[Modagger]

Probably something with the start winding. Which is directly related to the governer, as that helps it connect/disconnect. If the capacitor isn't connected, that would also prevent the start winding from energizing.

The start winding provides the extra "kick" in the correct direction to help it get up to speed. Otherwise, the rotor could have landed in between the run windings, and will go to whichever is closer/easier (hence the flipping direction).

I’ve got the capacitor wired the way it was when I took the motor apart, so I’ll test it tomorrow.

Thanks!
Jeff

 

[Rick_Br]

You have a lt of smart folks helping you out with thismotor. The only thing I can add is that I have experienced this growling and random change to start direction - turned it was a badly routed wire that was preventing the start switch contacts from closing when the motor was at rest. Can you see inside the assembled motor to be sure the contacts are closed? Can you hear the start switch disengaging when the motor is shut off?

Rick

 

[FrankLee]

Yes. That sounds like the start circuit is open... the switch contacts are not closed, a break in wiring.

Can you see the switch contacts through the vents with power-off?

 

[Modagger]

You have a lt of smart folks helping you out with thismotor. The only thing I can add is that I have experienced this growling and random change to start direction - turned it was a badly routed wire that was preventing the start switch contacts from closing when the motor was at rest. Can you see inside the assembled motor to be sure the contacts are closed? Can you hear the start switch disengaging when the motor is shut off?

Rick

Thanks Rick

That’s where I’ll “start” this morning.

Jeff

 

[Modagger]

Yes. That sounds like the start circuit is open... the switch contacts are not closed, a break in wiring.

Can you see the switch contacts through the vents with power-off?

Thanks FrankLee

 

[Modagger]

You have a lt of smart folks helping you out with thismotor. The only thing I can add is that I have experienced this growling and random change to start direction - turned it was a badly routed wire that was preventing the start switch contacts from closing when the motor was at rest. Can you see inside the assembled motor to be sure the contacts are closed? Can you hear the start switch disengaging when the motor is shut off?

Rick

I compared the motor run sound to mine which is working fine. (I didn’t get my hands in it which is probably why). I can hear the start switch disengaging after it’s shut off.

So, I’m thinking I should test the capacitor. Yes, no? If yes, how do I do that without sending myself across the room? I have a multimeter.

 

[Modagger]

Thanks FrankLee

I just put an ohmmeter across the points where the leads are soldered onto the switch and there’s no continuity. With the switch idle it should be closed, correct?

 

[FrankLee]

Correct.

 

[Cruzan80]

Is it possible you bent it too far one way when polishing, so it is no longer making contact when idle?

 

[FrankLee]

I just put an ohmmeter across the points where the leads are soldered onto the switch and there’s no continuity. With the switch idle it should be closed, correct?

Correct.

Let me expand on that....

With the motor assembled and powered off, there should be continuity through the switch.

With the rotor removed from the motor, the switch will be open.

 

[Davefr]

Motors with centrifical start switches need to have the rotor perfectly centered in the stator and very minimal end play. If the rotor is too far in one directly the start winding will not disengage. If it's too far the other direction it will not start properly. Something a minor as a misplaced washer or bearing positioning can cause this.

As you proceed with your troubleshooting just don't let the start winding remained energized for more than a few moments or it will fry. They cannot tolerate being continuously energized.

 

[Modagger]

Correct.

Hmmm

Motors with centrifical start switches need to have the rotor perfectly centered in the stator and very minimal end play. If the rotor is too far in one directly the start winding will not disengage. If it's too far the other direction it will not start properly. Something a minor as a misplaced washer or bearing positioning can cause this.

As you proceed with your troubleshooting just don't let the start winding remained energized for more than a few moments or it will fry. They cannot tolerate being continuously energized.

Stop the brain trust!

As I was tilting at windmills, I paused and started replaying all of the great tips from you folks. One thing stood out: FrankLee mentioned that he had a similar model motor as mine and his had a fiber shield between the switch and the mounting points. So I disassembled the motor one more time and put a 1/16” washer under each screw. Bingo! I’ve just finished cycling it on/complete stop 30 times and it’s performing perfectly.

I just came in to report and saw your post. Thanks Davefr

 

[Modagger]

Let me expand on that....

With the motor assembled and powered off, there should be continuity through the switch.

With the rotor removed from the motor, the switch will be open.

Yes!

Thanks once again FrankLee and everyone else who helped!

 

[FrankLee]

it’s performing perfectly

Great news!

 

[Modagger]

Is it possible you bent it too far one way when polishing, so it is no longer making contact when idle?

If you mean the switch, all I did was spray it with contact cleaner.

 

[Modagger]

Great news!

Working like I never laid a hand on it.

 

[Cruzan80]

If you mean the switch, all I did was spray it with contact cleaner.

Glad to hear it was working. The reason I had asked about bending is the thought process that maybe it wasn't making contact. Sounds like it was the right train of thought, with the washers fixing it.

Just trying to lay out the reason behind the question for the next person, not saying you did anything improper.