NEMA 48 Cradle mount resilient rings

R

RobertB

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Attempting to restore a vintage motor and need a source for these mounting rings.

O.D. is standard NEMA 48/56 2-1/2" and inside is 1-3/8" square. I can find plenty of round and hex inside ones but no square ones. If I could find a round one with a small enough I.D. that I could cut the square from would be great, but hours of googling have yet to find any suitable.

ring1.jpg
 
Like you, I found a quick search turned up nothing.

Your best bet might be to cast a set out of urethane. https://www.smooth-on.com/tutorials/ Not difficult or expensive but would be a bit of a project. Maybe time to learn a new skill :)
 
Yeah Jim, I considered that as I have a good bit of experience in mold making and casting. If this was not a one-off (well technically a two-off) project it would be a viable solution. The problem that I have faced in the past is that the mold and casting resins are kind of pricey and have a very short shelf life. You use 8 ounces out of a gallon and by the time you need it again it has gummed up in the container. So far the best I can come up with is a sheet of 1/2" polyurethane rubber from McMaster-Carr and cut them from that.

Motor is about 80 years old and I suspect that the square mounts were obsoleted many years ago in favor of the hex design that is now available. But I can hope :)
 
How about 3D printing?
 
matthewsx said:
How about 3D printing?
Click to expand...
That actually is a good question. I'm not familiar with the types of materials available for printing. The only items I have seen 3d printed have been from harder plastics, are softer rubbery type items possible? ( in a hobby level machine)
 
RobertB said:
That actually is a good question. I'm not familiar with the types of materials available for printing. The only items I have seen 3d printed have been from harder plastics, are softer rubbery type items possible? ( in a hobby level machine)
Click to expand...

I'm not a 3D printing guy so I don't know exactly what's out there but I"ll bet something is available. There's a 3D printing section on here but I'm sure there are others that specialize. First step would be drawing up the part, once you have a good drawing someone should be able to make it for you in various materials.

Cheers,

John
 
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