Bridgeport Motor Issue (Video)

metric_taper said:
Seems if the actual motor does not match the nameplate, I would guess it had been rewired by a motor shop in the past.
It does not make sense that the VFD drives the grinder but not this motor. All you did was paint it? Just the exterior, and did not split the bell housing off like you have for the photos? Have you tried running the motor with without connecting the shaft to the machine?
Click to expand...

Yes, this is the first time I've pulled it apart. I have not tried running the motor with the shaft free of the machine. Are you thinking maybe the machine is frozen and not allowing the motor to spin up? I don't think that's the case. I can freely spin the spindle in gear and out of gear. The motor did spin, albeit very slowly in the video posted early in this thread. I guess pulling it and testing it on the bench is the only way to truly know that there isn't a problem in the bull gear/etc. And I suppose I'll probably need to take it to a motor shop to get them to rewind it or at least test it to make sure I'm not just a moron, so it has to come out anyways. I'll give it a shot tomorrow.
 
Ceej0103 said:
Yes, this is the first time I've pulled it apart. I have not tried running the motor with the shaft free of the machine. Are you thinking maybe the machine is frozen and not allowing the motor to spin up? I don't think that's the case. I can freely spin the spindle in gear and out of gear. The motor did spin, albeit very slowly in the video posted early in this thread. I guess pulling it and testing it on the bench is the only way to truly know that there isn't a problem in the bull gear/etc. And I suppose I'll probably need to take it to a motor shop to get them to rewind it or at least test it to make sure I'm not just a moron, so it has to come out anyways. I'll give it a shot tomorrow.
Click to expand...
Did you take the other bell housing off the motor? Might be good to look at the winding and any connection wires between them there just to make sure nothing looks wrong. I think it would be wise to power just the motor without the mill load to see if it will spin up.
the link to the VFD indicates it is a vector controlled. They typically have an 'auto tune' feature, that is performed on the motor unloaded. I would try that and see if it may fix what has been a hidden problem. As always, RTFMFO. :D
 
metric_taper said:
Did you take the other bell housing off the motor? Might be good to look at the winding and any connection wires between them there just to make sure nothing looks wrong. I think it would be wise to power just the motor without the mill load to see if it will spin up.
the link to the VFD indicates it is a vector controlled. They typically have an 'auto tune' feature, that is performed on the motor unloaded. I would try that and see if it may fix what has been a hidden problem. As always, RTFMFO. :D
Click to expand...

I did not take the other end bell off the motor to take a look. I didn't because I pulled it out today and put it on the bench. I hooked the VFD back up and powered it. The rotor spun up pretty well, but no where near 1760 RPM, which I believe is what these 3-phase 1 1/2HP motors should achieve at full potential. I energized it while holding the Vari-Disc and the motor couldn't overcome my resistance to letting it spin. If it couldn't overcome my grip, there's no way it was going to overcome the resistance placed on it when it's installed in the machine, driving the gear train. I'm fairly certain I have something going on in the motor. I took it to a local guy here that really know 3-phase motors and he said he's 100% certain someone has been inside and modified the original windings. Anyhow, he's going to surge test it tomorrow and will give me some feedback.

I'll update this when I find out whats going on with it.
 
You may want to search for a new motor from eBay, search for a frame type 145T. There are many new and used. I don't know what the "Y-T" frame modifier code does to the motor. But you either get one with the same shaft size, or you could get one with a bigger one, and remove the rotor, and machine it down on the lathe. One word of caution, make sure the transition from the larger shaft to the smaller machine shaft has a radii in the inside corner.
I learned this the hard way.
I did this on my lathe (7/8" shaft to 5/8" original 2 step pulley) when putting a 3 phase on it, there was just enough eccentricity of the old pulley, that it caused the shaft to snap off at the sharp inside corner. It ruined an inverter duty motor. I tried to press the shaft out of the rotor, and it broke one of the cast iron bucking plates on the harbor freight 20 ton press, this shot out sideways, and broke through the sheet rock wall, only stopped by the external plywood sheathing of the building. Never could get the shaft pressed out of the rotor. It sits as a project. And I was lucky it did not shoot at me, as it would have done some body damage.
 
The "T" in the frame size say's the shaft diameter is the same, at least per this:
www.hecoinc.com

What Electric Motor Frame Sizes Tell You

It is important to understand what the motor frame is telling you when it comes to mounting a motor. Make sure you know what to look for before you mount your motor.
www.hecoinc.com www.hecoinc.com
The "Y" the motor has special mounting dimensions. That may be an issue, or you make an adapter plate.
 
metric_taper said:
You may want to search for a new motor from eBay, search for a frame type 145T. There are many new and used. I don't know what the "Y-T" frame modifier code does to the motor. But you either get one with the same shaft size, or you could get one with a bigger one, and remove the rotor, and machine it down on the lathe. One word of caution, make sure the transition from the larger shaft to the smaller machine shaft has a radii in the inside corner.
I learned this the hard way.
I did this on my lathe (7/8" shaft to 5/8" original 2 step pulley) when putting a 3 phase on it, there was just enough eccentricity of the old pulley, that it caused the shaft to snap off at the sharp inside corner. It ruined an inverter duty motor. I tried to press the shaft out of the rotor, and it broke one of the cast iron bucking plates on the harbor freight 20 ton press, this shot out sideways, and broke through the sheet rock wall, only stopped by the external plywood sheathing of the building. Never could get the shaft pressed out of the rotor. It sits as a project. And I was lucky it did not shoot at me, as it would have done some body damage.
Click to expand...
metric_taper said:
The "T" in the frame size say's the shaft diameter is the same, at least per this:
www.hecoinc.com

What Electric Motor Frame Sizes Tell You

It is important to understand what the motor frame is telling you when it comes to mounting a motor. Make sure you know what to look for before you mount your motor.
www.hecoinc.com www.hecoinc.com
The "Y" the motor has special mounting dimensions. That may be an issue, or you make an adapter plate.
Click to expand...
metric_taper said:
Forgive my ignorance on Bridgeport motors. Looks like it is a "C" face motor. And it's non standard or custom. Same problem I have with my Wells-Index mill.

Bridgeport 2HP Motor-New - Industrial Control & Automation

Bridgeport 2HP Motor-New
www.icai-online.com
Pricey fix.
Click to expand...

Glad you dodged that bullet. Yeah that's what I've gathered from my google searching when this issues arose. I was thinking just to replace it with a decent inverter duty motor, but looks like finding something that has the correct shaft length/diameter is challenging. Then you need to make an adapter plate to mount. This sounds like a cool project, but when your mill is down and your lathe's 5hp motor is sitting on the floor next to it, that would be a tough job.

That's definitely a pricey replacement for only 2 HP. I paid half that for a very nice 3-phase 3HP Baldor for the grinder.

I did read that H&W sold an adapter plate, but that post/thread was really dated and I'm not finding anything like that on their current offerings. We'll see what my motor guy says.
 
metric_taper said:
Forgive my ignorance on Bridgeport motors. Looks like it is a "C" face motor. And it's non standard or custom. Same problem I have with my Wells-Index mill.

Bridgeport 2HP Motor-New - Industrial Control & Automation

Bridgeport 2HP Motor-New
www.icai-online.com
Pricey fix.
Click to expand...

Found something...little better. Would like to get to 2HP if I'm investing the money. Maybe they can just sell me the adapter plate.

www.machinerypartsdepot.com

Three Phase Conversion Kit for 1 HP Bridgeport Motor | SP23PH

Lead time is generally 3-5 days to ship.
www.machinerypartsdepot.com www.machinerypartsdepot.com


EDIT: Nevermind, I think this is for the step pulley configuration.
 
$650 for a single phase motor is a bit steep when you could get it for half price here...

www.ebay.com

1.5 HP Baldor Reliance 35M691-3032G1 | eBay

Find many great new & used options and get the best deals for 1.5 HP Baldor Reliance 35M691-3032G1 at the best online prices at eBay! Free shipping for many products!
www.ebay.com

you'll still need to punch out the pulley to 7/8"
 
Ulma Doctor said:
$650 for a single phase motor is a bit steep when you could get it for half price here...

www.ebay.com

1.5 HP Baldor Reliance 35M691-3032G1 | eBay

Find many great new & used options and get the best deals for 1.5 HP Baldor Reliance 35M691-3032G1 at the best online prices at eBay! Free shipping for many products!
www.ebay.com

you'll still need to punch out the pulley to 7/8"
Click to expand...

That particular package was 1 HP (1J stock BP) to a 3-phase 1.5HP Baldor. But yes, still a little expensive. When you say "punch out the pulley", what do you mean? I have a vari-speed machine and the drive aspect of the motor is the var-discs and they have bushings. So if I were to buy a different motor with a larger shaft, I understand boring out the internal diameter of the vari-disc and cutting a new keyway, but I'm not quite sure how the bushings would be solved. Just find some suitable bushings and install them in the vari-discs?
 
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