At the beginning of the build season, we (4183) decided that we wanted to build a robot that scored in the high basket from the key. To do so, we quickly decided to build a turreted one-wheeled shooter, since we believed it to be easier to tune and to have more backspin than a two-wheeled design. Also, some of our mentors had successfully used a similar shooter in 2009. We built a plywood prototype using a 4" PVC roller covered with a material similar to sandpaper, but with an adhesive backing. We used bent steel conduit as the hood. This shooter demonstrated that our general idea worked, but was not sufficiently powerful. Here's a video of a test of the prototype:
http://www.youtube.com/watch?v=CQPIT...hannel&list=UL
We designed a shooter in Autodesk Inventor that used 8" wheels from the 2010 KoP. Since we weren't sure what the best launch angle, we designed the shooter to allow conduit ball-guides of any shape. It is powered by 2 FP motors. Here is a (rather ugly) render:
http://www.bitbuckets.org/wp-content...ter_render.bmp
We made two changes to this design. We cut off the tall triangular section at the top to reduce height and weight, and we eliminated most of the holes along the top and side, since they would take an obscenely large time to laser-cut. We did not finish our shooter during build season, so decided to keep it and attach it at the Utah Regional. We built a wood stand to mount it for testing. After watching videos from some early regionals, we decided that fender shooting would be much easier than key shooting, particularly because we were unable to develop computer vision. Fortunately, we were easily able to modify our shooter for a higher launch angle. We were surprised to find that we could still shoot from the key with the higher launch angle, a fact which we took advantage of in autonomous. Video of us testing shooter from "fender":
http://www.youtube.com/watch?v=RWCIPrSPUkg
Image of shooter:
http://www.bitbuckets.org/wp-content...7/IMG_3147.jpg
Image of turret:
http://www.bitbuckets.org/wp-content...7/IMG_3151.jpg
Few hardware modifications were made to the shooter during competition season. The shooter worked as expected, scoring ~75% from the fender in teleoperated and ~50% from the key in autonomous. Our lack of a good aiming system probably contributed to most of our misses.