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Building Tips and technical articles. => Building techniques => Topic started by: John Craig on January 03, 2014, 06:38:37 AM
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I have never bent an aluminum gear blank before.
What is the most accurate & most efficient way to bend a 3/32 Sig gear blank ?? Radius of bends? Measuring to allow for the radius of bends? Most likely problems to watch out for?
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It takes practice to get it right as far as dimensions. The radius of the bend should be 4 times the thickness of the material I was told one time. A good heavy vise is desirable to hold the item for the radius. Also a good rubber mallet. Don't forget patience.
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I believe, and may be dead wrong, but the AL has to be gently heated. D>K
No!!! The aluminum should bend just fine dead cold. About the only thing you can do with heat-treated aluminum with heat is to anneal it, which softens it up until either you heat-treat it again, or it hardens itself over time.
If it cracked you were probably trying to bend it over too small a radius.
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I have never bent an aluminum gear blank before.
What is the most accurate & most efficient way to bend a 3/32 Sig gear blank ?? Radius of bends? Measuring to allow for the radius of bends? Most likely problems to watch out for?
John,
Must be your own design?
Take the blank to your local Body Shop. Bet they have a "brake."
What, four bends.
Probably do the bends for free.
Sheetmetal shop also.
For my The New American aluminum gear, I just sent a full scale drawing to Brodak. Sent me a gear bent right on the money.
Charles
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wait, alll depends on alloy type, some of them are easy to bend cold and some of them must be heated and some are soft after heating ... if it is duraluminum (probably is), it must be heated, then it needs to cool down slowly, then it bends nicely and after some time it gets its strength again (few days, but already after 1 hour it is so strong that it bends visibly harder then immediately after heating) ... the best is if you have piece for testing
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Search on YouTube for "bending sheet metal". You'll find lots of videos, some of which may even be useful.
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I just mark my reference point and clamp it in a vise against a piece of 5/32" (or larger) music wire and then bend it over that. Just don't try bending it without using some sort of radius behind it for support, if you don't you'll be almost guaranteed of cracking it. Also, BEFORE you make the bend, double check yourself and make sure you make your bend in the direction that you had planned on.
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My thanks to everyone for there suggestions & comments. I think I now have enough information to give it a try & have a good chance of success.
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may be one link can help: http://www.dbsportandscale.com/How%20to%20bend%20duralumin.htm
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may be one link can help: http://www.dbsportandscale.com/How%20to%20bend%20duralumin.htm
Igor,
Wow! Great info and thanks for posting the link.
Exactly what you said I believe. Kudos!!
Charles
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yes but nothing will replace personal experience, it is really very helpfull to try it with small piece of THAT material