http://www.youtube.com/watch?v=Mb0_i3hbVNY
Here is what team 571 has come up with for our final kicker. We use 2 6'' Pneumatic skyway wheel's as our ball magnet. Our kicker started as a prosthetic foot but due to packaging issue we settled on an 842 inspired design that packages very well around the wheels. we now use 7 wraps of surgical tubing from the upper part to a cross bar. We are now consistently getting a distance of 22-24 feet with this set up. We pull it back with a 1.5'' cylinder with 4.5'' of stroke and preload with a standard gate latch. The best part if you watch around the 13-14 second mark is the amount of arc we get with the rollers on. When they are off we get a lower trajectory which is also nice. Looking down the blue stripe is the 3'' of intrusion, Silver is our bumper zone, and green is outside of our bumpers. This was the best way for us to allow the kids to visualize as we kept trying different concepts.