Pneumatics vs. Passive

dsc_0010-2As mentioned in a previous article, our strategy was to focus on scoring gears, so we built many prototypes to perfect this important function. We finally settled on a hinged gear funnel  with a slot in the middle to allow the hook to lift the gear out of our robot. The funnel slants forward which gives it an impressive catch radius. During the design’s testing, some students expressed concern that fuel (balls) being shot into the high goal would miss and land in our gear placer, rendering it useless. There were two solutions: placing a pneumatic piston to open and close the gear catcher or cut a hole the size of a “fuel” to allow it to funnel down and exit without stimulation. We debated this idea but ultimately putting a pneumatic piston on held no value, it was too late in the build season to test new ideas and it was completely untested, unlike the passive design which has proved itself multiple times.

The idea behind the passive design is a device is more reliable with less actively moving parts. The goal was to catch and score gears. The team decided the most reliable way to do that was to do it without the aid of any actuation.
The benefit of this hinged design is it starts folded in and when the match starts, our robot’s movement causes the front hinged panel to fall naturally due to gravity (which is pretty reliable). Since it is hinged, it also allows us to get as close as we can to the hook; unlike previous hinge-less gear catcher designs, which prevented us from getting very close to the hook. When the gear was being lifted out of the robot, it would fall off the hook because it was too far out.  This new gear catcher was tested at the practice day at Jesuit and it was very successful.