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Unread 03-04-2006, 00:04
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iR3 Creative
AKA: Dan Richardson
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Team Role: Engineer
 
Join Date: Feb 2003
Rookie Year: 2001
Location: Ft. Lauderdale FL
Posts: 1,120
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Re: pic: Bent IFI Wheel

I don't know 1902 used these wheels and had a tough time with them. We have a 6 wheel drive train that can be seen here

These wheels are no longer on the robot, in fact from the moment we used them they caused nothing but trouble. The bearings and the wheels ( we used the 8"x1" ) combined with the 36 tooth sprockets, 3/8" shaft and AndyMark transmission could not handle the first competition, in the application we used them. From the picture you can generally tell the way we ran our chains and the tension systems used and the way we ran the chain.

Like the picture above we have a bent wheel, in the finals matches in Florida the top bent 1/3 the way off the wheel. We had absolutely no way to fix the problem we ran our auton and were out of the match. We constantly had trouble with our bearings shifting and the structural integrity of the wheel shifting a few degrees to the side we would turn. ( the shift was such that if you grabbed the wheel on the top and the bottom and pushed slightly on the wheel you could see the shift and it would remain there ) When the wheels would turn the shifting would cause the chains to jump, we could not get any uniform concentric movement out of the wheels they would always shift. It was unfortunate but our solution was to add chain guards and change the back wheels with skyway you get in the kit. The change worked decent until the wheel bent open and fell apart in the finals match at Florida. This model just seemed not to handle the twisting forces too well.

Unfortunately we had to take all the wheels off and replace them with skyway wheels which we trimmed down the rubber and used the remaining spare tread and hardware to assemble these wheels. ( I'll be posting pictures of our changes as soon as I can. )

The good news is the solution worked, since changing the wheels we've not thrown one chain not broken one time, in fact we went 11-2 in Houston and undefeated in qualifying.

IFI wheels are a good design it just seems that our application of them could not be supported by the structural integrity of the wheel. This was a shock to us because we didn't use them in any extreme situation just a typical FIRST drive train. But having talked with other teams they seem to work well on some of the smaller models ( or the same size but wider ). It just happened to be our size which did not perform well. Maybe thicker material? Maybe an inter-structural system on the sidewalls and sturdier bearings?

For us however it was just an unfortunate series of events maybe but we have $500 in wheels sitting in a box in my garage that we can't fix.

IFI is a great company and makes very good products, they saved our butts in Houston overnighting a new set of hardware and sprockets to us for our new wheels that we had unfortunately left in Orlando. It just happens that these wheels did not perform as desired and it did cause some disappointment. However I do believe that with some further testing, and some modification for next years model they can be performing as originally intended.
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