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1966 Bridgeport Mill 3/4 HP, single phase question

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Plastic
Joined
Nov 25, 2015
I just purchased a 1966 Bridgeport Mill that has a 3/4 HP, single phase motor (110/220 VAC) that appears to be original. I have two questions about this motor:

1. I can't find anything that says Bridgeports were made with 3/4HP motors. Everything I find says their smallest motor was 1 HP - is this the original motor? It looks original.

2. I've only run it up one-time to drill 30 1/2" holes through .125 thick material. I did stack the material so I was actually drilling through a thickness of .625. After drilling four holes I noticed the motor was extremely HOT and the drill slowed to almost a complete stop with almost not effort. I immediately stopped what I was doing. I didn't notice any smoke coming from the motor, but it was way too hot to touch. I will admit I miscalculated my speed for the material I was drilling. I was running it at 1115 instead of the 660 I should of set it for, but I was using lubricant and I wasn't applying excessive force. I mean, my grizzly drill press with 1/2HP motor hogs through mild steel with a 1/2" drill bit, so I fear this motor must be shot.

- Is my motor shot, or are the 3/4 HP BPs that weak?
- It's wired for 115VAC - will wiring it for 220VAC correct this? I know it will the lower the amperage.

Any tips or ideas for me to check out wiould be greatly appreciated.

Thank you!
 
It's a j-head with a step pulley. I apologize but I can't figure out how to post pictures on this forum.

Someone 5 years ago had the exact same question on "garage journal", so i resurrected their thread from the dead last night and on that forum I was able to post pics.

If you'd be willing to google "Id single phase 115v/230v milling machine motor" you'd find my post with about 7 pictures. I know this is an inconvenience for you guys trying to help me, but when I tried to post a link it stated the moderator had to approve it first and it still hasn't been approved, I guess.

One of the photos is the motor plate stating it's a GE motor, model #: 5KC180FJ222A, Number: HE, 3/4 HP, 115v/230v, single phase, 60 Hz, 11.6 / 5.8 amps, and its stamped "Bridgeport Milling Machine".....

Again, I apologize about the inconvenience of having you look at another website, but any assistance would be greatly appreciated.

Thanks,
Iz
 
You have to become a member on "garage journal" to view your pictures.

If you think a hefty size motor is going to be better, not true. A BP is a light to medium duty mill. Try to take a hog cut on almost anything, except plastic or wood, and the whole thing shakes unless you bolt it to a concrete floor. Then still I don't know how much better it gets. With that said, the manual does say to bolt machine to a concrete floor at all four corners on the base.

Probably what is stock for your mill is a 1Hp 3 phase motor.
 
I'm not trying to put a larger motor on it, but I am trying to figure out if the motor is shot or if I should wire it for 230 to solve the heating issue. my 1/2 HP grizzly drill press has an easier time getting through .625 material, and that just doesn't seem right.

I also would like to find a wiring schematic for the GE motor because I can't find anything on the motor. I'd assume someone on here had seen a 3/4 HP - single phase Bridgeport before and might have some insight.

If not, I'm wondering if I stumbled on a rare model or modified one.

Thank you for your input.
 
Your mill has had 51 years of opportunity to be modified. Have never heard of a 3/4 Hp single phase motor on a BP as stock. Rewire for 220v.
 
i wish I could post pics or a URL - does anyone know how long it takes the moderator to approve URLs?

I tried running the motor with no belt and it got hot with nothing on it within 2-3 mins.

I would love to rewire for 220 if someone knows where I can find a schematic or how to even verify its correctly wired in its current state.
 
I just tested it running with no belt so there was zero load on the motor and the motor got hot within 3-5 mins.... smh... I wish I could find a schematic or something to show me how to rewire it.

Side note- how long does the moderator take to approve the URLs? I wish I could post pics to this site.

Thank you,
Iz
 
I just tested it running with no belt so there was zero load on the motor and the motor got hot within 3-5 mins.... smh... I wish I could find a schematic or something to show me how to rewire it.

Side note- how long does the moderator take to approve the URLs? I wish I could post pics to this site.

Thank you,
Iz

That does not sound good. They are discussing your approval status under the cone of silence...

cone-of-silence-1.jpg
 
It's a j-head with a step pulley. I apologize but I can't figure out how to post pictures on this forum.

Someone 5 years ago had the exact same question on "garage journal", so i resurrected their thread from the dead last night and on that forum I was able to post pics.

If you'd be willing to google "Id single phase 115v/230v milling machine motor" you'd find my post with about 7 pictures. I know this is an inconvenience for you guys trying to help me, but when I tried to post a link it stated the moderator had to approve it first and it still hasn't been approved, I guess.

One of the photos is the motor plate stating it's a GE motor, model #: 5KC180FJ222A, Number: HE, 3/4 HP, 115v/230v, single phase, 60 Hz, 11.6 / 5.8 amps, and its stamped "Bridgeport Milling Machine".....

Again, I apologize about the inconvenience of having you look at another website, but any assistance would be greatly appreciated.

Thanks,
Iz

That GE part number is for a well-regarded motor in BeePee use.

Suggest you remove it and take it to a proper motor shop for a look-see and estimate.

If that is not in the budget, start searching for another motor.

There are practical limits to what can be done over the internet when 'too hot' is the most you can do, locally.
 
A motor getting that hot at all is indicative of a bad winding/stator/field/whatever word you use for it. There is a slight chance your bearings are tore up, but I would go first with a bad winding. Do you have a megger or a DMM to at least check the resistance of the motor?

Rumor has it that Bridgeport offered these as custom orders, we get them in rarely.

Jon
H&W Machine Repair
 
Have never heard of a 3/4 Hp single phase motor on a BP as stock.

You need to get out more. Single phase motors were a common option for J head machines. My neighbor bought one that way. The first PB that I ran in 1965.

OK, on to the OP. If the motor plate does say 110/220 single phase, you need to check the wiring inside the junction box. You should also check the switch. There are numerous schematics available for wiring on the web.
JR
 
I just tested it running with no belt so there was zero load on the motor and the motor got hot within 3-5 mins.... smh... I wish I could find a schematic or something to show me how to rewire it.

Side note- how long does the moderator take to approve the URLs? I wish I could post pics to this site.

Thank you,
Iz

How do you know that the start capacitor is not disconnecting?
 
You need to get out more. Single phase motors were a common option for J head machines. My neighbor bought one that way. The first PB that I ran in 1965.

OK, on to the OP. If the motor plate does say 110/220 single phase, you need to check the wiring inside the junction box. You should also check the switch. There are numerous schematics available for wiring on the web.
JR

Yeah, I should have realized that the option is for the home body type of guy.... :nopity:
 
Yeah, I should have realized that the option is for the home body type of guy.... :nopity:

LOL! If one is to take a 'superior' position, 3-P, over 1-P this would be a rather poor example to start from!

I've got a vintage Cast Iron Hobart mixer 43 years in the kitchen with more power than that PeePee Bee Pee. Dovetail ways the bowl is run up and down on are smaller, but the head is prolly about as as rigid as a Bee Pee, too. At least at what it as asked to do.

:D
 
Update: I took the motor to a motor shop and they found out it was actually wired for 230v. I deployed right after getting this back from the motor shop, so I haven’t done anything with it since my original post. Now I’m wondering how to wire it for 120v. Anyone know where I can find a wiring schematic? I tried googling it, but no luck.

Model: 5KC180FJ222A
Single Phase
115v/230v

Thanks.
 








 
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