Gear Failure Question

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ScaleCraft
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Gear Failure Question

Postby ScaleCraft » Wed Sep 01, 2021 5:42 pm

Not 0. Actually #1 gauge.
USA 44-tonner, new axles, wheels and gears. Sent to a customer for display running by a good friend of mine.

We have NEVER seen these PRC drives chew up a brass worm like that.
Lubed, confirmed, all I can tell him with the lack of worm gear damage s SOMEBODY took the bottom cover off and the square journal bearings got installed wrong. Blombergs, square to rails, SD-40's diamond, cannot remember 44 tonner.
Told him I'd ask here.

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Dave....collector, restorer, and operator of the finest doorstops

bob turner
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Re: Gear Failure Question

Postby bob turner » Wed Sep 01, 2021 7:05 pm

Brass is a horrible gear material. Expect a brass gear to fail in the first hour.

Bronze, Celcon, steel - even bakelite - way better (hundreds of hours, if not thousands.

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ScaleCraft
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Re: Gear Failure Question

Postby ScaleCraft » Wed Sep 01, 2021 7:07 pm

True. But. Rule-of-thumb is worm has to be harder than the worm gear. And in 25 years of these things, we have never seen a brass worm to THAT, and never seen geartrain failures with axle wormgear intact like that.
Dave....collector, restorer, and operator of the finest doorstops

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robert.
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Re: Gear Failure Question

Postby robert. » Wed Sep 01, 2021 7:46 pm

What lube did you use? If somebody put an EP lube in there it will eat yellow metal. EP( extreme pressure)
I spend entirely too many hours a day tying my shoes

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ScaleCraft
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Re: Gear Failure Question

Postby ScaleCraft » Wed Sep 01, 2021 8:05 pm

I think he said HobbyLube.
Dave....collector, restorer, and operator of the finest doorstops

bob turner
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Re: Gear Failure Question

Postby bob turner » Wed Sep 01, 2021 10:11 pm

Are you sure your earlier gears were not bronze? Sunset went to bronze gears after a number of failures, and you couldn't tell by looking at them. Ditto NWSL.

Brass just disintegrates in gear service. Almost anything is better - I have a crummy Loco Works plastic worm that has lasted decades. It is just dirtbag plastic, not even Celcon.

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ScaleCraft
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Re: Gear Failure Question

Postby ScaleCraft » Wed Sep 01, 2021 10:22 pm

All USA engines have brass worms. Some king of plastic worm gear. Highest failure is splitting wormgear hubs. Never, ever seen a brass worm do this in a USA engine.
Dave....collector, restorer, and operator of the finest doorstops

bob turner
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Re: Gear Failure Question

Postby bob turner » Thu Sep 02, 2021 12:20 am

Can you tell us what alloy USA Engines uses? You are sure they have never changed alloys? Or are you relying on sales literature?

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ScaleCraft
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Re: Gear Failure Question

Postby ScaleCraft » Thu Sep 02, 2021 12:36 am

Good question. Most of the PRC crap we have to deal with just uses...brass. I have no idea the alloy, but knowing how them clowns work, cheapest they can get.
However, those worms worked fine until the plastic wormgear split, and were replaced....then the worms died.

I cannot imagine how plastic gears could strip out brass like that.
Dave....collector, restorer, and operator of the finest doorstops


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