This is a recap of our final 2022-2023 season, including our time at the FTC World Championship in Houston. Most of the team is graduating and there are no plans to continue. It was a pleasure to meet so many of you over the season and at Worlds. Thank you to everyone for your support and encouragement over the past 14 years.
For those who are interested, here are our design changes and motivations:
Cone grabber: We tried many designs but concluded that having double claws that opened fully and pinned the cone stack against the wall gave us the most room for error. The gripper liner was silicone for stickiness backed by soft foam for compliance. We knocked over some cone stacks mid-season (Chesapeake states) because of a bug where the claws didn't open fully. For maximum grip, we used an adhesive-backed silicone sheet from www.mcmaster.com/9010K43/.
Lift: From VEX and Gluten Free's Skystone robot, we knew that a linkage or double-reverse-four-bar (DR4B) lift design would be faster than string-powered drawer slides. We tried to combine the stability of drawer slides with the speed of DR4B, but could never get this to work well. Prototyping string drawer slides with constant-force springs and a simulated weight convinced us that this would be fast enough. We used these CF springs on every stage of Misumi SAR230 drawer slides: www.mcmaster.com/catalog/129/....
Extension: We had the idea to do pass-through even early in the season to minimize turret rotation, but hadn't solved the sequence problem of having the MGN slides extend before the drawer slides. Instead, we went with a crane design in the first scrimmage, but the cycles were slow as we had predicted because it took time for the crane to settle after the turret turned 135 degrees. When we came up with the locking design to sequence the MGN and drawer slides (Misumi SAR340), we were able to switch to the pass-through design with the turret only turning 45 degrees. We tried some MGN slides from Amazon but these were still affordable and much more reliable: www.zyltech.com/zyltech-mgn9-....
Swinging arm: We used 2 Axon MAX servos to power this. We were not able to use the silver ProModeler DS630BLHV servos that we had used in Freight Frenzy since they didn't travel the required 180 degrees. The blue Amazon 35kg servos couldn't handle the stress of the load and broke frequently. Axons gave us the required travel angle, were as reliable as the ProModelers, and were quite a bit cheaper.
Differential cone-grabber "wrist": Andy came up with this idea after learning about differentials online. Even though the rest of us weren't sure about such a major change so late in the season, he was able to design and program it within a few days and we ended up putting it into the final robot. Late-season scrimmages proved out its durability and usefulness.
0:00 - Introduction
0:10 - Prototyping
0:27 - DR4B prototype
0:54 - DR4B testing
1:06 - Countersprung lift
1:29 - First functional robot
1:39 - Gann scrimmage
1:42 - Switch to pass-through design
1:53 - First teleop and 1+5 auto
2:13 - Lexington qualifier
2:23 - Fallen cone prototypes
2:34 - Optimizations & driving practice
2:48 - Norfolk qualifier
3:02 - Needham qualifier
3:11 - Chesapeake championship
3:29 - Game strategy and differential grabber
3:47 - Driving lessons with Spot
4:03 - Reveal filming & Spot
4:10 - Scrimmages & prep for Worlds
4:24 - Worlds arrival & setup
4:45 - Worlds days 1 & 2
5:14 - Worlds day 3 & alliance selection
5:37 - Worlds final day
5:56 - Farewells
6:27 - Speeches
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