Harbor-Freight 3 in 1 Motors?

Richie B.

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My Harbor Freight/Central Machinery Model 44142 3-in-1 lathe/drill/mill has a habit of blowing capacitors. My motor shop tells me I would be better off with a yankee motor (Baldor) [higher duty cycle] but the Chinese sheaves have a Metric bore. I've looked in catalogs but can't find comparable diameter sheaves to fit the Baldor shaft sizes.

I theory I could bore out the Chinese sheaves and install plugs with the right bore for the Baldor shafts, but I don't have internal keyway capability.

Have any 44142 owners (it's my avatar) made this swap? I'd like to know how you did it and what motors you used.

Thank You! :)

Edit: I've owned this since 2002 and still have the manual. If anyone needs one, I can scan it.
 

JimDawson

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Is the Baldor motor a NEMA 56 frame? If so, then it's a 5/8 shaft. What size is the pulley? Step Pulley? There should be something pretty close.

Actually you do have a keyway cutter. You can mount the pulley up in the lathe chuck, and use a boring bar with a tool bit ground to the right width and hand cut the keyway by running the carriage in buy hand. Take small bites at a time.
 

Richie B.

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Is the Baldor motor a NEMA 56 frame?
Thanks for your reply! I don't have the motor shop's notes here, but IIRC it was 3/4hp and only a 1/2" shaft. Smaller than the sheave bore. It would fit the HF/CM motor mounts with only a bit of modification.

Actually you do have a keyway cutter. You can mount the pulley up in the lathe chuck, and use a boring bar with a tool bit ground to the right width and hand cut the keyway by running the carriage in buy hand. Take small bites at a time.
That's a pretty neat idea. I think the sheaves are only cast iron so it should carve pretty easily. I might be able to run the tailstock in by hand and chip away at it too.
 
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bvd1940

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You coul hook up a dc treadmill motor and have variable speed as a bonus in the deal. You can find treadmill motors for free on CL just for the hauling away.
 

Richie B.

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You coul hook up a dc treadmill motor and have variable speed as a bonus in the deal. You can find treadmill motors for free on CL just for the hauling away.
But are treadmill motors reversible???
 

Dociron

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It'll be much easier to use the boring bar in the tool post as you can feed the compound in to get the depth you need for the key.

How would you accomplish that with the tail stock unless you have a boring head that fits your tail stock quill?
 
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bvd1940

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Yes they a reversible and work pretty nice at the free price, you just have to stop before you throw the reverse switch. I put one on my Atlas drill press and it worked great. I have upgraded my drill press to a industrial vari speed powermatic drill press.
Gl
 

Falcon67

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You coul hook up a dc treadmill motor and have variable speed as a bonus in the deal. You can find treadmill motors for free on CL just for the hauling away.
I would say you see treadmills sometimes in the free zone, but whether you can use the controller or mount the motor easily is another question. I tore down the one we had here thinking maybe to use it on the 9x20. The controller in the treadmill was forward only and the motor was mounted with a custom frame. So there's expense in adapting, buying a motor controller, etc - and I called "not worth the hassle" then threw it all in a box somewhere.

Sounds like at least an import sourced broach would be worth getting for this project LOL.
 

Happycamper

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I just bought one of the HF 1 hp motors and bolted it to my table. It worked and then I found a new Leeson 1hp DC motor on ebay. Bought a KB controller and love it. Has the brake switch, for/rev and speed controller. No more changing belts. Bought a cheap hand held laser tachometer and noted the rpm for each percentage on the speed controller. After installed I had about $300 invested. Love it.

And on the broaching thing. Look up mrpete222 on YouTube. He is a retired shop teacher and has hundreds of videos on how to do stuff. One was on cutting key ways with the lathe. He also has a web site with a list of all the how to videos. Goes by Tubalcain. :.
 

compsurge

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What quality capacitors were installed to replace the originals?
 

Richie B.

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What quality capacitors were installed to replace the originals?
I'm not sure who that question was directed at, but here's my motor & cap spec.

LatheMotor.jpg

Two motors; one for lathe, one for mill. Same model motor, each has two caps [start/run]. I'm not an electrical guy, this cap was installed by a garage electrician. It works, but I've been unable to find this cap on the Net. I'd like to get a few spares before I convert to a Baldor setup.

Two questions:

(1) Would the start cap be the same as the run cap?
(2) Is a 2-cap motor 'better' than a 1 or 0 cap motor?

Thanks for your help! :)

LatheMotor.jpg
 

compsurge

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I'm not sure who that question was directed at, but here's my motor & cap spec.

View attachment 90132

Two motors; one for lathe, one for mill. Same model motor, each has two caps [start/run]. I'm not an electrical guy, this cap was installed by a garage electrician. It works, but I've been unable to find this cap on the Net. I'd like to get a few spares before I convert to a Baldor setup.

Two questions:

(1) Would the start cap be the same as the run cap?
(2) Is a 2-cap motor 'better' than a 1 or 0 cap motor?

Thanks for your help! :)
A quick search yielded these:
http://www.grainger.com/product/DAYTON-Motor-Start-Capacitor-2MDT2
http://www.digikey.com/product-detail/en/PSU27015A/338-2748-ND/1551663
>>>http://www.mouser.com/ProductDetail/Cornell-Dubilier/PSU30015/?qs=sGAEpiMZZMv1cc3ydrPrF6n/KlM53Ws8/XwlzoF5nMY=
http://www.newark.com/cornell-dubilier/psu27015a/capacitor-alum-elec-270-324uf/dp/72K6679
>>http://www.amazon.com/Amico-300MFD-Terminal-Starting-Capacitor/dp/B0087ZBOLO (300uF, 250V)

You're looking for a 300uF capacitance on the start capacitor. There is obviously a tolerance, and it appears the replacement part you have is around 270uF +/-10%. It should be close enough.

The voltage rating is what it can withstand. If you see a lot of voltage spikes, you may want to go to a higher voltage like the last cap I linked. I'm not entirely sure if the rating on the caps is RMS voltage or not.

My EE buddy says to make sure you run it at least once a month to keep the capacitor charged, otherwise they can degrade over time. It's less of an issue with potted caps, but can happen.

What is the failure mode you are seeing? Is the capacitor exploding? Losing the ability to start the motor?


If I read your motor spec chart right, I believe the run capacitor is 35uF.
 

compsurge

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When it works do you hear the centrifugal switch engaging? If it doesn't your motor never decouples from the start circuit and it will burn out since it's not meant for continuous duty. The capacitor could be the weak link in this system and die over time.

Here's a great video on motor function I found while trying to find a sound of the centrifugal switch.

Anyway, I'm trying to find the root cause of your issue versus tell you to go the immediate replacement route. I'm sure the HF motor is very inefficient and getting a Baldor will get you a reliable, well-made motor, but the old motor might be repairable.
 

Richie B.

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When it works do you hear the centrifugal switch engaging?
When the motor starts, I can't even hear the TV in my shop. The Chinese weren't concerned about noise pollution.

I'm sure the HF motor is very inefficient and getting a Baldor will get you a reliable, well-made motor, but the old motor might be repairable.
Both Chinese/HF motors are in use & running now with aftermarket yankee capacitors. They work OK but my motor guy tells me that a Chinese 3/4 hp motor is not the same as say a Baldor 3/4 hp motor. If I'm going to be replacing caps every 18 months or so, I either need a steady supply of caps or new motors...

I would retire the Chinese motors in running condition and keep them for spares.
 

wa5cab

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Richie,

The problem with the power rating of Chinese motors these days (I'm not sure this was true with the ones from Taiwan back in the 70's and 80's) is that they are rated by the input, not the output. Your motor nameplate reads 550 Watts. One horsepower is about 746 Watts. So the INPUT power is 0.73 HP. Assuming an electrical to mechanical conversion efficiency of around 70% gives an output of about 0.53 HP. So your Chinese 3/4 HP is about what a US manufacturer would call 1/2 HP.

The replacement start capacitor you bought is about 270 ufd +/- about 20. Your motor nameplate calls for 300 ufd. However, if it starts quickly, I wouldn't worry about it, Your 3-in-one is shouldn't be a hard to start load. And I don't see any reason why you should have to replace the capacitor annually. The run capacitor, on the other hand, calls for 35 ufd. Don't skimp on that one as it could matter.

FWIW, the motors on my 4X6 Bandsaw and my drill press are both over 30 years old and both still work just fine. But only time will tell whether the same will be true of what the Chinese are selling today.

Robert D.
 

Richie B.

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To be clear - I bought this in 10-31-2002 and it's been in use regularly [weekly] since then. Three caps have been replaced; two on the lathe motor, and one on the mill motor. Not all at once, several years apart. I don't know which were replaced, whether run or start. I'd assume the start since they smoked & wouldn't start up.

I know nothing about motors or capacitors, and the caps have several slide connectors. My motor guy did the connections.

I'll check those links in compsurge's post; at the least I'll have a cap on hand for my motor guy when it next burns out.

Thank you all! :)
 

Richie B.

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The black cap I pictured several posts above this (with the motor ID plate) is a replacement from the motor shop. I dug through my old parts box and found one of the original burnt-out caps (the blue one below). I also took the plastic cover off the mill motor and took a pic of that cap (white one). The blue & white are off the same motor but are physically different sizes - the plastic covers are even different (one fat, one thin).

OEM_caps.jpg

I have no idea which is a start and which is a run...How would I tell???

Should I get spares of each??? Or is there one cap that will work for either start or run???

Thanks for your help!

Edit: My recollection of that blue cap 'burning out' was that it was the first one to go. The lathe started up very slowly...I had no idea why it was turning over so slow since it had worked OK the day previous...Then it started to smoke & stink... :(

OEM_caps.jpg
 
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mrbreezeet1

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I would say you see treadmills sometimes in the free zone, but whether you can use the controller or mount the motor easily is another question. I tore down the one we had here thinking maybe to use it on the 9x20. The controller in the treadmill was forward only and the motor was mounted with a custom frame. So there's expense in adapting, buying a motor controller, etc - and I called "not worth the hassle" then threw it all in a box somewhere.

Sounds like at least an import sourced broach would be worth getting for this project LOL.
i am a far throw from a electrical expert, but from my understanding, a reversible switch is quite easy to tie into the motor.
"Every picture tells a story" (that was a good jam)
see if I can find the one I had.
It is a DPDT switch.

switchwire.jpg
 

compsurge

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On the nameplate you have 300 and 35 uF. The 300uF is the starting capacitor and the 35uF is the running capacitor.
 

Richie B.

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On the nameplate you have 300 and 35 uF. The 300uF is the starting capacitor and the 35uF is the running capacitor.
Thank You! I am a millwright by trade; wiring a house is pretty much the limit of my electrical capability.

So, if I were to get a 300uF 250/300v cap and a 35uF 250/300v cap, I would have a set of run/start caps for emergencies??? Or is there some critical difference between a run and a start capacitor???
 

compsurge

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The caps I linked earlier should be good for starting capacitor. They are rated for 125VAC (again, the voltage rating is just what the capacitor can handle - higher will be fine, but likely cost more). If you need a running capacitor, you change the filters on those site's search pages for 35 uF and you should be good (they even label motor run vs motor start capacitor).

Both caps should be similar in physical size to that they are replacing so they fit in the motor's housing. You don't have to be perfect on the match, but get as close as you can. I don't know what the OEM motor spec for tolerance is, so get as close to the nameplate as possible +/-%.

Here is a sample run capacitor that should work:
http://www.mouser.com/ProductDetail/Cornell-Dubilier/SFP24S35K375A/?qs=JlSiUoO6twkxQypibr45LQ==
http://www.mouser.com/ProductDetail/EPCOS/B32332I6356J82/?qs=sGAEpiMZZMv1cc3ydrPrFyAEDdQ02CGeTFmI6u1kbkY=
http://www.mouser.com/ProductDetail/Cornell-Dubilier/23FB4435-F/?qs=sGAEpiMZZMv1cc3ydrPrF8gMTJ0uZsYNKiIhvdTDv4A=
Here was the search: http://www.mouser.com/Passive-Components/Capacitors/Film-Capacitors/_/N-9x371?P=1z0wqr8

These are capacitors from only one site. Hopefully you are armed with enough knowledge to make an educated purchase now. If in doubt, post it!
 

wa5cab

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Richie,

The short answer is "yes". However, if you are only going to run the motor on the 120 V line, as Compsurge wrote you will probably pay more for the capacitors. But, If the motor happens to be reconnectable for 240 V, then you should buy the 250 to 300 volt rated ones. The next owner might decide to reconnect for 240 (I would) and not knowing that the motor has 120 V capacitors in it, do some damage when they quickly fail.

The difference between a start and a run capacitor is two-fold. The start capacitor will generally have a much higher capacitance. But it is rated only for intermittent operation. Once in a while the specification sheet will be detailed enough to show the duty cycle, which will be something around 10%. Meaning for example 10 seconds on, 90 seconds off. The run capacitor will be lower capacitance but still about the same size. It is rated for 100% duty cycle (continuous operation). Which is why it will be as large as the start capacitor but with around a tenth of the capacitance. However, if you just pick one that the catalog says is a start capacitor and one that it says is a run capacitor, and if the listing shows HP ratings, match that, too, then you'll be safe,

Robert D.

So, if I were to get a 300uF 250/300v cap and a 35uF 250/300v cap, I would have a set of run/start caps for emergencies??? Or is there some critical difference between a run and a start capacitor???
 

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Capacitors on a 120v motor need to be rated much higher than 125 volts. Normal household voltage (120 is the "rms" value) actually has a peak voltage about 160v; and spikes can go higher than that. Using a capacitor rated for 200 volts will give you much better service.
 

John Hasler

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Capacitors on a 120v motor need to be rated much higher than 125 volts. Normal household voltage (120 is the "rms" value) actually has a peak voltage about 160v; and spikes can go higher than that. Using a capacitor rated for 200 volts will give you much better service.
He wrote "125VAC". That means that it is designed for operation on the AC line and designed to take the peak voltage it will see there.

You would not want to use a 125VDC capacitor on the 120VAC line.
 

Richie B.

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That brings up another question: Are capacitors polarity-sensitive??? If I have two wires coming out of the motor for each capacitor, does it matter which side of the cap gets which wire???
 

John Hasler

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That brings up another question: Are capacitors polarity-sensitive??? If I have two wires coming out of the motor for each capacitor, does it matter which side of the cap gets which wire???
The AC-rated capacitors used in induction motors are unpolarized.

Electrolytic capacitors used in electronic circuits are polarized. They have "+" and "-" signs identifying the leads and say DC on them. If you try to use one on a motor it will explode.
 

Richie B.

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I guess my next question is where is a good place to order a pair of 300uF/250v Start caps and 35uF/250v Run caps??? Amazon does not list anyone selling the 35uF caps, and the Mouser caps list minimum quantity:32...

I'm not into electronic parts suppliers; the only catalog I have here is from Grainger, and they don't list the 35uF/250v Run caps...

I'm also in an industrial-challenged area; if there's an electronics supply facility around here, they're well hidden...
 

wa5cab

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Richie,

As John implied, the answer is "no". It does not matter which of the two wires goes to which of the two terminals.

The majority of electrolytic capacitors made are polarized or polarity sensitive, and are marked with the polarity (+ and/or -). However, the motor start capacitors made today are all electrolytic, and non-polarized. And certain electrolytic capacitors made for other type service are also non-polarized. Perhaps the most common application would be in solid state audio power amplifiers.

The run capacitors may or may not be NP electrolytic. 50 years ago, they weren't (they were oil filled), but that could have changed. I'll have to look into that.

Robert D.

That brings up another question: Are capacitors polarity-sensitive??? If I have two wires coming out of the motor for each capacitor, does it matter which side of the cap gets which wire???
 

wa5cab

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That's correct. "VAC" instead of just "V" implies RMS of a sine wave. And when used in the voltage rating of a component, it also implies a safety margin appropriate to the typical service the device is intended for. The actual peak to peak voltage rating of a Start capacitor for use on the 120 VAC line is probably around 300 V.

Robert D.

He wrote "125VAC". That means that it is designed for operation on the AC line and designed to take the peak voltage it will see there.

You would not want to use a 125VDC capacitor on the 120VAC line.
 
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