Rouge River Workshop: A Motor Find

Some years ago, I had dropped by the city's household hazardous waste depot on my way home from work to offload some old paint and motor oil. I spotted this motor lying on the pavement just outside the big roll-up door to the place.

No one's name was on it aside from the manufacturer's (Franklin), so I put it on the truck and went home with it.

It's 3/4 hp, 3,450 rpm and it runs perfectly. It's just what I need to power an old table saw I want to restore. The only snag is that it has no mount. It's what's known as a 'C-Face' motor -- its output end is a precision flange with four threaded holes in it for bolting the motor directly onto a gearbox, or whatever machine the motor is to be the input to.

So, I'll have to come up with a mount for it that will let me mount it in conventional fashion behind a saw. That's going to be a bit of a challenge. When that's done, I'll tear the motor down and give it a paint job. This may take a while.

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SUNDAY, MARCH 4, 2012

Mount -- C-Face Upright Beginnings

This motor's frame is a NEMA 56 configuration, so I was able to confirm my layout measurements from NEMA data. The ticklish part of this piece of the mount is cutting a 4 1/2" diameter hole in a board to accept the face of the motor. I have a fly-cutter that can do that. Setting the thing up can be a bit of a chore. Here it is ready to go.

I know of no way to accurately preset a fly-cutter for a given absolute dimension. You have to do it by trial and error on scrap material. Down in front you can see where I was doing just that on a piece of trash material.

I got a shot of the cutter in action, just for the heck of it.

And here's the cutter with its prize at the end of the cut.

Note the c-clamps. You don't even think about using a fly-cutter this size on hand-held material. To be safe and successful, a fly-cutting job must be securely clamped up. Use only the drill press' lowest speed and a sharp cutter. Everything must be tight. Slow, easy even feed gets the job done with no untoward events.

Once I got that piece of work free of the drill press table, I drilled the four bolt holes that I'd already laid out and spotted before starting on the big hole. Here it is trial-fitted to the face of the motor.

It's a start. There's much more to be done, but so far, so good.

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Update -- SATURDAY, DECEMBER 8, 2018

It's been a long time-out from this post. The motor mount is built, though I've yet to include motor mount fastening holes/slots. Here are some photos of the assembly so far.

And now it's time for a teardown. I'll add fastening holes/slots to the motor mount's base-plate, and give the motor and motor mount a paint job.

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Motor Mount Base Slotted -- MONDAY, DECEMBER 10, 2018

The slots are 5/16" wide, for tolerance for 1/4" fastening bolts. Slot length is one inch effective.

Motor Torn Down

Here's the business end apart.

The bearing is an NTN 6203, shielded both sides. Bearing dimensions are 40mm O.D. x 17mm bore x 12mm wide. The bearing is in good condition, and needn't be replaced.

Here's the other end of the rotor showing the centrifugal start switch actuator.

Here's the wiring end of the frame.

Unless you have an infallible photographic memory for such things, always make a sketch of wiring connections before dismantling a piece of gear like this. You may think you'll remember how everything goes together -- you may not.

And here's a view of the end bell with the terminal board and some other electrical items.

They managed quite a neat packaging job of all that in a very small space.

The start capacitor is a made in Canada Mallory, 159 microfarad, 110VAC P/N 275469-110.

The thermal protection device is a Klixon No. CEG64DV. "D4H" is also embossed on its body.

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Here's the output bell-end masked for painting.