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Aermotor A702 cracked/ broken hub

Posted: Tue Jan 07, 2020 7:11 am
by bluezx6r
Hi all, I've got an Aermotor A702 with a broken piece on the front of the hub where the spokes thread into it. The previous owner did a spot weld to hold it together, and had the spokes threaded in and up on a tower outside, but not using it. I dont trust the weld job as is, however if one took their time and did a good weld, do you think the hub will be salvageable to function as intended again? Just curious what your experiences have been which such repair.
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Re: Aermotor A702 cracked/ broken hub

Posted: Tue Jan 07, 2020 7:33 am
by windybob
From what I can tell, the short answer would be yes. Just my opinion.

Re: Aermotor A702 cracked/ broken hub

Posted: Tue Jan 07, 2020 6:32 pm
by JLM
Good properly prepared welds made with nickel will hold up to alot of stress.

Re: Aermotor A702 cracked/ broken hub

Posted: Thu Jan 09, 2020 7:41 pm
by bluezx6r
Good copy, thank you gentlemen!

Re: Aermotor A702 cracked/ broken hub

Posted: Tue Jan 14, 2020 5:15 pm
by Ron Stauffer
This isnt an easy slam dunk as it appears as the breaks both appear to be thru the wheel arm holes. It is very hard to get good realignment of the threads when there is a break across two holes as cast can stretch before it breaks. Check the alignment & looseness with a good bolt of proper thread. Use the other holes for comparison. You can have a weld that holds but can also have a hole that wont keep a spoke.

The old welds are not Ni so that is a hindrance to a "good" weld. Also your breaks are thru the holes where you have the least amount of material to weld at.

Dont rely too heavily on "it was up and spinning as is" as sites will vary on the stress it put on a mill And a furled mill has less stress than one that is always open.

Check the Ni rod cut sheet in the other post for the desired rod to use.

Ron Stauffer
Montrose CO

Re: Aermotor A702 cracked/ broken hub

Posted: Tue Jan 14, 2020 7:56 pm
by JLM
Ron is spot on about those spoke holes. If this mill was a rare hard to find mill or a has sentimental value I would repair it. Or if your trying to save money and repair it yourself. Otherwise you are better off to chunk it and get another hub and shaft assembly. Loose or crooked spokes can be a wreck at the least the wheel will not track properly/wobble or worse allow the wheel to hit the tower.