Old capacitor start motor....metal lathe.. don't have enough data. Attention moderato

[Dweeber]

All,

Unsure if this is posted correctly, moderators step in...

I am attempting to re-wire a motor driven south bend lathe, EICOR made for FAIRBANKS-MORSE, which has no labelling or wiring diagram. The data plate has the following:

model: CS-73-26; 1/2 hp: 60 hz; 1725 rpm; 115/230 1 phase; currently operate at 115v.


The motor is on a aged southbend metal lathe, which dates to the '30's or 40's, which precedes me by a small margin. The attempt to make a reversible motor operation is keeping me from trying anything. I am afraid to make things worse, the motor works in forward.

The motor came with the lathe, which happens to be a shop lathe, sitting in a cramped corner, which now has importance; seeing as we've a "new" man in shop, but he's my senior and had at one time operated such a machine.

The NEMA configurations seem not to apply for this motor. Any help is appreciated, feel free to question what info I've provided. I've got 6 identified terminals on the motor, the #6 doesn't have a stud. Also, the drum switch is a furnas r12, which pre-dates me as well. The motor terminals are jumpered from 1 to 2, and 3 to 4, leaving five free and no area to land 6.

Any help with the motor diagram is thanked,

Google search has been fruitless.

D.

 

[dicklaxt]

Why would you want to reverse a lathe,just curious?

dick

 

[PetrosA]

Some lathes need to be reversed when using a form to guide the cutter, since the form gets mounted on the opposite side to where the operator normally stands.

 

[ActionDave]

I am attempting to re-wire a motor driven south bend lathe, EICOR made for FAIRBANKS-MORSE, which has no labelling or wiring diagram. The data plate has the following:

model: CS-73-26; 1/2 hp: 60 hz; 1725 rpm; 115/230 1 phase; currently operate at 115v.

The motor is on a aged southbend metal lathe, which dates to the '30's or 40's, which precedes me by a small margin. The attempt to make a reversible motor operation is keeping me from trying anything. I am afraid to make things worse, the motor works in forward.

The NEMA configurations seem not to apply for this motor. Any help is appreciated, feel free to question what info I've provided. I've got 6 identified terminals on the motor, the #6 doesn't have a stud. Also, the drum switch is a furnas r12, which pre-dates me as well. The motor terminals are jumpered from 1 to 2, and 3 to 4, leaving five free and no area to land 6.

D.

Yeah buddy! The NEMA configurations don't apply to those old motors and then there is the chance that the motor has been rewound. A few thoughts come to mind-

You do know two things for sure with a cap start motor; there is a set of running windings and starting windings. They can be traced them out visually or with an Ohm meter.

From what I gather in your post two of the leads to the windings, five and six, are not attached to anything. That is rather confusing.

Does the motor run on 120V with a load on it? How fast does it come up to speed?

 

[Dweeber]

picture attached...

picture attached...

First off,

Thanks for all that have responded. The lathe is functional without reversing the motor, but some tapping and other machining operations use reverse. I am not knowledgable in that area.

I am going to describe what I've witnessed. The motor works well on 120v, forward. No overheating, funny smells, noises, nothing.

In order of terminals, the top one is 5, the next down is 1 jumpered to 2, then 3 jumpered to 4, then a square slot for 6, which really does not exist.

I am afraid I will have to dismantle this to figure it out, but was hoping some other folks already had and I'd use their experience.

So, looks like I am again in for a learnin'. By the way, I did not wire this.

D.

 

[hurk27]

First off,

Thanks for all that have responded. The lathe is functional without reversing the motor, but some tapping and other machining operations use reverse. I am not knowledgable in that area.

I am going to describe what I've witnessed. The motor works well on 120v, forward. No overheating, funny smells, noises, nothing.

In order of terminals, the top one is 5, the next down is 1 jumpered to 2, then 3 jumpered to 4, then a square slot for 6, which really does not exist.

I am afraid I will have to dismantle this to figure it out, but was hoping some other folks already had and I'd use their experience.

So, looks like I am again in for a learnin'. By the way, I did not wire this.

D.

It looks like the black (bottom black wire going into the motor) and the red under terminal 2 are the wire to swap to reverse the rotation, those should be your start windings.

You will need to bring 4 conductors and the EGC from the drum switch to the motor, the supply will run to the drum switch also, the drum switch should swap the red and black start winding conductors mention above, in referance to the two line conductors.

Here is about the closes diagram I can find for a motor like yours, it is faily close except it has one of the line conductors landed on the 0 terminal:





If it turns out that the one line conductor does need to land on that terminal then you will need 5 wires W/EGC between the motor and the drum switch.

If you need help with the drum switch wiring, maybe I can help.

 

[hurk27]

Here is a diagram on how a drum switch works and how to make it swap the start winding leads:
Look at the motor diagram in the upper left:




If the way your motor is wired as in your photo then here is how it should wire up to the drum switch:

L1 from supply to term. #6 on the drum, L2 (neutral) to term #2 on the drum, wire from term. #2 on the drum to term #4 in motor, jumper term. 3 to 5 in drum, then run wire from term 5 in drum to term 2 in motor, remove red wire from term 2 in motor and remove black wire from term 4 in motor, red wire will run to term 4 in drum, and black wire will run to term 1 in drum.

If the motor runs reversed from the way you want it with the switch, swap the red and black at the motor or switch.

This will wire your motor just like the one in the diagram for the drum switch above with only 4 wires and a EGC between the motor and drum switch.

 

[Dweeber]

still deciphering...

still deciphering...

Hurk,

Thanks for the picture, but I'm not at work, so further investigation will have to wait. I think that I will remove the end bells, if I am to figure this out.

I will take more pictures at work, then use the home computer to upload them to this site.

Anyone have recommendations regarding the centrifugal switch removal process?

So far, I do thank those that have replied. I plan to take several pictures in the event that anyone may come across the same obstacle. So far I've seen exactly one motor like this on Google images. Perhaps there may a long-lived reference?!

D.

 

[Dweeber]

typing slow

typing slow

Hurk,

Please understand that my previous post that was written prior to your last, but posted later. I need a bit of time to look deeper at the drum switch setup.

Thanks,

D.

 

[hurk27]

Hurk,

Please understand that my previous post that was written prior to your last, but posted later. I need a bit of time to look deeper at the drum switch setup.

Thanks,

D.

no problem, you should be able to hook it up as above without pulling the motor apart, if it is running as wired now, swapping the red and black will reverse the motor.

 

[steve66]

If the motor wasn't designed for reversing while running, you may not have much luck getting it to reverse without stopping it first.

Not exactly what you want for tapping.

 

[Dweeber]

Cap...

Cap...

Steve66,

I have the forgetfulness of my father, and his father...and is doesn't seem to get better with the birthday cakes!

I am insure of motor theory, but just about any single-phase, cap-start motor should be reversible, but I've been wrong so many times that I cannot say anything with certainty.

So far, I have to be humble and attempt to figure this out, and perhaps along the way, help some future folks in the event they may stumble across an EICOR motor, made early, prior to the NEMA standards.

I will post my findings, as they "may" provide ample information, but I abhor incorrect data. Please continue to respond to my posts, I need the schooling.

D.

 

[GeorgeB]

left hand threads

left hand threads

If the motor wasn't designed for reversing while running, you may not have much luck getting it to reverse without stopping it first.

Not exactly what you want for tapping.

Some of us find that tapping left hand threads works better with the part rotating the other direction ...

 

[steve66]

Some of us find that tapping left hand threads works better with the part rotating the other direction ...

I'm thinking they need to tap a hole that has a limited depth. So the motor has to reverse quickly to avoid bottoming out and breaking the tap.

But you may be right - they may not need that.

I didn't mean you can't wire the motor to run in reverse. I meant you may not be able to connect a switch that reverses the motors direction, and expect it to work while the motor is at full speed.

 

[ActionDave]

I am insure of motor theory, but just about any single-phase, cap-start motor should be reversible, but I've been wrong so many times that I cannot say anything with certainty.....

You can reverse a cap start motor, but you do it by switching the connections on the starting winding.

When the motor is up to speed the starting winding is not in the circuit so you need to stop the motor before it can reverse.

 

[sgunsel]

There are many reasons to run a lathe in reverse. Examples, parting off with the parting tool on the opposite side of the lathe bed and running in reverse is common; reversing to start multiple threading passes; backing the tool out of a part. Probably lots more, but I'm not a machinist. I don't think I ever saw a lathe that could not be reversed. And yes, single phase motors have to stop (almost) before reversing - which isn't all bad because otherwise you can easily unscrew the chuck which never ends well. Happens with 3 phase motors that are easy to reverse while running.