Motor Frame Material Make Up

[Lost_Case]

What type of cast iron material are modern electric motor frames made from? I had an engineer tell me gray iron.

Any suggestions would be greatly appreciated.

 

[jraef]

Depends on the quality of the motor.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[electricpete]

We had one cast frame motor with a crack in the foot. We had a vendor do some kind of "stitching" repair on the crack (we have no way to repair a crack in cast iron ourselves since it can't be welded). If I remember right, the repairer said on the phone that he suspected it was grey iron (even before he had seen it) because that was a common construction. At least I'm about 50% sure that's what he said (it's been awhile).

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(2B)+(2B)' ?

 

[dArsonval]

The OP has possibly asked a question that can not be answered in a forum board.

One would have to go directly to the manufacturer of the motor, OR have a piece of the motor iron analyzed
to determine if it's cast iron, gray iron, ductile iron, etc.

The same would be true to determine what kind of steel went into a motor's weldments if the motor was
built using welded formed steel. There's no way of knowing unless it's analyzed, or data is provided
by a manufacturer.

The information would likely be proprietary even if you were to find someone at a factory willing to
speak to you about it.

Great question. If/when you find out for certain... come back and fill us in.

John

 

[Lost_Case]

I am just looking for basic information. I have called around to a few motor manufactures and all have claimed proprietary metal formulations. I had one shop tell me that a motor frame could be built of rolling steel and forming the frame that way versus going through a cast process.

 

[EdStainless]

Proprietary as in the cheapest stuff that the foundry would pour.
With old motors there is a regional aspect to this, in some parts of the country the go to was a ductile iron, in others only gray.
Newer ones could be formed and welded steel.
In most cases it doesn't really matter, a good motor can be be made with any of them as can a poor one.

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P.E. Metallurgy

 

[electricpete]

If you're looking for a starting guess on the range of properties:

https://books.google.com/books?id=D... Casting Materials for Electric Motor&f=false

Mechanical Design of Electric Motors, by Wei Tong, CRC Press
Table 5.1, Properties of Some Common Casting Materials for Electric Motors...

They list grey and ductile iron and three varieties of aluminum in this reference.

By the way, it looks to me like it might be a pretty good book .... wondering whether it might be worth $67.

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(2B)+(2B)' ?

 

[dArsonval]

That book appears to be a very good find Pete.
Sixty seven dollars will likely purchase something more important right now... but for the electric motor aficionado,
it may not matter.

John