With 1 week left, we finally started to put together most of the vital pieces to the robot. We ran into the issue where spacing on the discs was very critical, and the slightest adjustment would either make them grip the balls too much, or not enough. So the addition of foam on the inside of one disc would help compensate for the variation in spacing.
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| Green foam on inner disc |
Another vital part of the ball collection mechanism is the hopper. We cut and mounted the hopper ramp, but there still needed to be some sort of walls to keep the balls from falling out. So we cut and mounted some 1/16 inch aluminum sheet metal for the side-skirts. They are also notched at the electronics box hinges to still allow access.
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| Side-skirts for hopper |
The other mechanism we added was a front channel to help channel the various balls into the collection mechanism. It is comprised of Vex c-channel about 12 inches long each. They are mounted with a piano hinge on the inside of the chassis and with a slotted L-bracket on the outside.
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| Front channel (far right) |
The additions to allow the robot to realize it has backed in to the home station are two limit switches at the very back of the robot. These will allow the robot to perfectly line up with the home station. Another limit switch we added was for the trapdoor so the robot will be able to open and close the door accordingly.
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| Limit switch on back for home station |
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| Limit switch on top bracket of trap door mechanism |
While coding, I realized that any metal in the immediate vicinity of the compass module would cause erratic readings. To address this, we had to come up with a mount that was void of metal for the most part. We cut a piece of 1 inch diameter pvc to about 7 inches for the main mount. To hold the compass module in place, we used a piece of fairly rigid foam and inserted the connectors for the compass. I also fished the wires through the pvc.
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| Side view of compass mount |
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| Top view of compass mount |
