pg. 14 (3DP Award cont.)
-We also learned that a tolerance of .02 inches was required when creating shafts or other structures that may need to connect to other precisely measured components. This was true for the measurements of the feeder wheels as compared to the dimensions of the ball and was also true for the openings for the hex shaft – any smaller and it wouldn’t fit, any larger and it wouldn’t hold the shaft using rotation.
-Finally, this project has underscored for us the importance of aesthetics. We tried many kinds of materials, sizes, configurations, etc. for the rubber treads attached to the feeder to increase friction. When we found the most effective design, we epoxied the tread and attached, as it happened, brightly colored rubber bands to keep the seal while the epoxy cured. After the epoxy had dried and set we realized we actually liked the way the rubber bands looked. Tests were done to ensure the rubber bands did not inhibit the behavior of the tread to grip the ball during feeding. Once we determined the rubber bands had little effect we decided to leave them on…and this was one of the things the judges and other teams said they really liked about our robot!
II-III. 3DP Knowledge Base Enhancement Your Team Made
The 3D printed models we created included rough drafts and final versions for the following parts used on our competition robot:
-Continuous wheel ball feeder.
-Camera mount (holds the AXIS camera on the robot at the specified angle required by our drive and programming teams).
-Wi-Fi router mount (holds the router in a place where the referees can see it clearly and makes it easier to connect and disconnect the router from the robot).
-Spacers used in various places in our robot, including the drive train and our feeder system.
-Winch spacer for the gear box mounting (ensures that the aluminum tubes stay a specific distance from each other so that there is no additional strain on the gear box. With this design, we learned that you have to be careful about over-tightening bolts on hollow parts.)
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specific distance from each other so that there is no additional strain on the gear box. With this design, we learned that you have to be careful about over-tightening bolts on hollow parts.)
-Hub caps on the top of the catapult support post and on the feeder arm (identifies the robot as Team 4201 in team colors of black and green. We learned how to do dual extrusion for this part to have the two different colors, and also learned to make text large in order for it to be legible.)
Because we designed all of our parts from scratch, we did not utilize any models or sources for 3D printing optimized parts.
II-IV. Online Contributions Your Team Made
We have posted the picture of our 3D printed parts as well as the program file on-line on our team website, and have begun to share this link to the pictures and blueprint with other teams and 3D printing enthusiasts through Facebook, model libraries, and Youtube. We also used hard copy because we distributed brochures and spec sheets at the Long Beach competition with the information on how to find the design files, as well as our offer to answer questions or provide assistance. This brochure will continue to be distributed at our school tours, interactions with other FRC teams (such as our upcoming practice with Team 330 Beach Bots), and with the FLL teams that we talk to.