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Old 09-14-2017, 01:32 AM   #1
lakeracer69
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Default Forming parts with rubber pad question

Here is a picture of .025 6061-T6 bent up into a rib web. It didn't bent up completely and I had to go the rest of the way in a vice. It came out alright for a first try, but I need to refine my process. It goes by the Guerin process, flowforming, rubber stamp forming etc.

The Bearhawk guys and others are using this process to bend up wing ribs with flanges, etc. For those that don't know, the metal blank is put on top of a particle board form and a thick ( 1") "rubber" sheet and steel plate are placed over it and tonnage is applied in a 20 ton press.

My question is what type of urethane or other material and durometer do I need to use. I am using a 1' thick piece of horse stall mat, but I think the durometer is too soft. Anyone know what the correct stuff to use is?

Thanks


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Old 09-14-2017, 02:12 AM   #2
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Best stuff in the world to use is gum rubber.
It's non porus, flows really good and lasts a long time.
You can get it from Zoro.


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Old 09-14-2017, 02:14 AM   #3
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Here's a hunk I haven't used yet and I think the pn is from Zoro.
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Old 09-14-2017, 02:14 AM   #4
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Forgot the picture
File Type: jpg 1505355282453.jpg (38.5 KB, 125 views)
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Old 09-14-2017, 08:52 AM   #5
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You need some more thickness on the rubber pad to start with. I seem to remember around 2x your die height for starters. Durometer is going to be above 60 I think. EAA has a little video on doing smaller parts with more info.
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Old 09-14-2017, 01:27 PM   #6
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Quote:
Originally Posted by cvairwerks View Post
You need some more thickness on the rubber pad to start with. I seem to remember around 2x your die height for starters. Durometer is going to be above 60 I think. EAA has a little video on doing smaller parts with more info.
Thank you both for the replies. I will double up on the pad that I have and try that and report back. Also found out you need to spray the part with a lube to help with the process. In this case they used "Pledge".I found that EAA video on you tube, I had seen it quite a while ago and couldn't find it.

The nice thing about this process is that small aluminum parts with correct corner radius's and dimensions can be made without a bending brake.


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