[Paul Copioli]

I guess I'll be the one to give the vital stats:

Drive bases - completely separate designs with no collaboration between the two teams. I'll let 229 describe theirs, but our drive base stats are as follows: Six wheel, six motor drive no shifting using the 4 CIMs and 2 FP motors with a top speed of about 9 ft/sec. The entire drive base structure is made from 1.3mm thick aluminum sheet metal. The design is much like that of an aircraft fuselage with all sheet metal components riveted together (111 inspired). Two free wheeling 128 counts/rev encoder wheels are used for navigation. We can get position and angle from these two encoders. The pump, drive transmissions, wheel bearing housings, drive victors, pump relay, power distribution, and battery are all housed within the drive base.

Tower assembly (stationary part) - Concept co-developed by both teams, but design details for the sheet metal were completed by 217. The actual fabrication was done by 217's sponsor. Again, all the sheet metal is riveted together. Pneumatic gauges, Clippard tanks, solenoids, spikes for solenoids, victors for the vertical lift, and the vertical lift motors are all housed on the tower. The vertical lift concept was developed by 229. 217 uses the two window motors with a chain drive for the vertical lift. 229 uses the Van door motor with one FP assembly and a cable drive. This difference was due to team preference (217 really likes the window motors and 229 really likes the van door motor).

Vertical lift (a.k.a. shuttle) - Concept developed by 229. Shuttle construction details refined by 217. The shuttle construction is modeled directly after an aircraft wing made from 1.3mm thick aluminum sheet metal. The vertical lift slider bearings usage was a 229 idea that was implemented to the sheet metal concept. The stationary stage of the linear bearings are riveted to the tower and the last movable stage is riveted to the shuttle.

Four bar arms and drive - 217 concept with 229 and 217 sharing the design details. One kit transmission modified for use with the Globe motor is used for the arm drive. The lower arm is direct drive from the output shaft of the kit transmission. Arms are made from PVC pipe (217 uses 1.5" and 229 uses 1.25") with a gas shock as a balancer. Both arms are perfectly balanced for one tetra.

Tetra Grabber - 229 concept with each team doing separate detail design. 2" cylinder with a 7" stroke was used for both designs. Pieces mostly made from PVC pipe (Team 71 inspired).

It was a very good experience for me and my students because 217 and 229 had such different design biases and backgrounds. We collaborated on what we could agree on and did our own thing on items we knew both teams would not compromise. The end result was two very similar robots with their own personalities.