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Unread 26-11-2008, 21:08
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R.C. R.C. is offline
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AKA: Owner, WestCoast Products
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Re: 4 inch Wheel of Doom

Quote:
Originally Posted by Travis Covington View Post
In 2008 and 2007 we had identical wheels, however, the 2007 wheels were 7075 (and were optimized to utilize the stronger material) With the required bumpers in 2008, we performed another analysis and deemed the 2007 design "good enough" if we just used 6061. I should note, however, that we did have one of our 2008 wheels bend ever so slightly (still usable), when the 2007 wheels held up to much more abuse with no bending.

Also, from my past research, I couldn't find 7068 bar in any sizes large enough to make wheels. Granted, I didn't look for plate, but what I did find was all pretty small. Did you guys acquire something large enough to do the wheels?

And again, to reiterate what everyone has said so far. You should expect your design to change dramatically when using a stronger or weaker material. With a higher strength material, pockets can get way deeper, web thicknesses can be reduced greatly and you can save a ton of weight if you optimize the design and remove material in the right places. It sounds like you've done that already. As a next step, you may just do some more research to see just how strong some of the plastics are versus the materials you have used thus far and have available to you. Strength to weight ratio is the key thing to look at here, and 7068 is near the top of that list if you are only concerned with the strength (ignoring elasticity, fatigue stregth, etc)
Thanks Travis for the info, the wheel previously posted was way overengineered and it weighed about .49 pounds. After talking with Adam, I got the wheel within .33 lbs. The donated 7068 was about 5.5 in diameter (rod stock), it was kinda like a early christmas gift. Not really expected. If we end up going with 7068, i'll be trying to get the weight down to .2-.28.
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