Drill press smoking. Help

[Zac wingert]

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Someone gave me an 8” craftsman drill press. He said he bought it New about 10-15 years ago and never really used it because he had his good one and this was his back up/emergency one. He is a retired welder.

When end I tested it out, after a few cuts, it started smoking. I initially thought it was because I had it on a higher speed than I should have. Drilling through pine with a 1/2 forstner bit. But the smoke was coming from the solenoid(??) shown above. It’s all melted. It looks easy enough to replace, what is it?

I want to fix it myself, even if it is financially not worth it. Sentimental value. I am not experienced with this sort of thing but there is no better time then now to learn, given that I can’t imagine this is too difficult. I am mechanically inclined, but horrible with electronics. I like fixing things.

[George Makra]

That's a start capacitor look at the label and you will see a funny symbol and a number.
That number is micro farads then go to fleabay type in start capacitor the voltage and the micro-farads.
After you spend very little on a replacement reinstall it its not polarity sensitive.

[Charles Lent]

You can also find replacements at a local electric motor repair shop, if there is one near you. You will need to buy a replacement with the same micro farad rating, a slightly higher voltage rating would be OK too, but it also needs to be the same physical size or very close to it, or it won't fit inside the cover. It's best to take the old one with you when you go to buy the new one. It is not polarity sensitive so no worry about that when it comes time to install the new one.

The other thing that you should check is that the centrifugal switch inside the non shaft end of the motor is working correctly. This switch has to open as the motor comes up to speed. There are fly weights and springs on the motor shaft that will move a plastic collar horizontally on the motor shaft as the motor comes up to speed. This collar pushes against the switch and disconnects the starting capacitor from the circuit. If the collar cannot move on the shaft, the capacitor will remain connected and it will either burn up, like the original did, and/or the motor start winding will burn up, destroying the motor. Motors that have not been used in a long time will frequently have this problem, usually caused by the plastic shaft collar not sliding easily on the shaft.

If you aren't comfortable with disassembling the motor to check and repair this, an electric motor repair shop is the best place to take it. They will replace the capacitor and test the motor to be certain that all is OK.

Charley

[Frank Pratt]

Some capacitors are polarity sensitive. You need to be sure to get one that is not. If you get one from a motor shop it won't be polarity sensitive.

[Joe Kaufman]

It could be a permanent split-capacitor motor where the starting winding is connected in series with the capacitor and parallel with the run winding. The starting winding does not drop out of the circuit and therefore no centrifugal switch or current relay is used. In this case the micro farad rating of the capacitor is important and needs to be the same value.

[Charles Lent]

It could be a permanent split-capacitor motor where the starting winding is connected in series with the capacitor and parallel with the run winding. The starting winding does not drop out of the circuit and therefore no centrifugal switch or current relay is used. In this case the micro farad rating of the capacitor is important and needs to be the same value.

This is highly unlikely for a small drill press motor. What I'm seeing in his posted photo is a single section capacitor with two connections.

Charley

[Mike Hollingsworth]

I've been very successful getting motor capacitors on Amazon.

[Zac wingert]

Thank you. The wires are crimped. Is that acceptable for replacement or solder?

[George Makra]

Thank you. The wires are crimped. Is that acceptable for replacement or solder?
And you could even wire nut them if you have the space.

[Charles Lent]

Wire nuts are not a good idea in machinery. Vibration can frequently loosen them. Go with crimped or solder connections. The wire connections at the capacitor are usually push on flat blade terminals. You may need to pull them free with a pair of pliers, but you shouldn't need to cut them off. The terminals are usually crimped to the ends of the wires.

Charley

[dan petroski]

Does smoking a drill press give you a SPIN 🤔 inquiring minds want to know dan

[Joe Kaufman]

Charley,

The point is, if the motor is a permanent split capacitor design, there is no centrifugal switch. I have run across it before on a similar small imported drill press,

The drill press application is a good fit:
Low cost.
Low HP requirements
Low starting torque.
Low duty cycle.
Smaller physical size - no centrifugal switch.

Definition:

A single speed permanent split capacitor AC induction motor has two separate pairs of series wound stator windings arranged at right angles to each other around the central rotor. The main run winding is connected directly to the AC power source while the secondary start winding is connected to the same source with a capacitor in series with it. The capacitor causes an electrical phase shift to the power in the start winding relative to the run winding, to produce a rotating magnetic field around the rotor which can start it turning. Since the capacitor remains in the circuit while the motor is running it's called a permanent split capacitor design.

[George Makra]

Lets make a simple project as complicated as possible so hat everyone can show off their superlative knowledge.
Verify the numbers on your capacitor but this one might do the trick.
You can always go higher in Microfarads but not lower i.e. you can replace a 5uf(microfarad) with a 7uf.
But you cant replace a 7uf with a 5uf.
Wirenuts are used all the time in machinery.
Do not worry it is a very simple project.

[Zac wingert]

Does smoking a drill press give you a SPIN 樂 inquiring minds want to know dan
I’ve had better.

[Zac wingert]

Lets make a simple project as complicated as possible so hat everyone can show off their superlative knowledge.
Verify the numbers on your capacitor but this one might do the trick.
You can always go higher in Microfarads but not lower i.e. you can replace a 5uf(microfarad) with a 7uf.
But you cant replace a 7uf with a 5uf.
Wirenuts are used all the time in machinery.
Do not worry it is a very simple project.

All the terminology kind of worried me, but nevertheless ordered a $10 capacitor on amazon with the same numbers. I’m gonna hook it up and see what happens. It’s coming from China so it’ll be a little bit of a wait.

[Ken Fitzgerald]

Zac...a photograph of the connections on the capacitor and a photograph of all the printing on the capacitor would eliminate a lot of the discussion here.

I agree with earlier comment, a replacement would preferably be soldered or crimped.

[Joe Kaufman]

The drill press would be considered a consumer product and therefore should have a UL listing. Harbor Freights 8" drill presses have the UL listing. Twenty years ago Underwriters Lab did not approve wire nuts as an acceptable method of wiring terminations and would not issue a listing or certification. I doubt if that has changed. One should not try to equate a consumer product with an industrial piece of equipment or installation as some rules are different. Just trying to provide information for your decision.