599C :
At CAMS final before side claws added. Shows good view of lift and collector in action. Its on Blue alliance paired with 599B claw robot.
Our 599C robot was able to extend 18 inches in about 2 seconds by driving both nested slides at once. The front two nested slides were synchronized by a common drive shaft. Same for the back two slides. The two sets of nested slides were mounted back to back and driven separately and simultaneously. The slide pairs were also offset to make the mounting easier. An encoder was attached to each slide and we positioned the lift height automatically based upon the sum of the two slides encoders. Although the slides were not synchronized it really didn’t matter since it was the total movement that concerned us. Each slide did have its own electrical position limit. We used a 36 tooth drive gear. In this configuration, the two motor pinions always had the same separation and could have been synchronized by a connecting chain however, this was unnecessary.
I really liked this design when combined with a perimeter tube collector. It could score and de-score with vertical motion. It also had and additional set of side claw grippers that could be used to de-score a stack of 4 tubes while simultaneously holding 4 of its own tubes. In one single move it could remove 4 tubes and drop 4 for a 26 point score turn around. The side claws were only one tube tall and pivoted on axles mounted on the side of the basic gripper.
It did have a few friction problems … and for some reason, we actually had two 393 motors fail during the same competition. One had a broken steel gear tooth and the other had excessive friction. You can get a glimpse of the 599C robot defending against the 599D collector robot in this video. (I think in this match, its upper lift was inoperable so it doesn’t seem to be doing much but defending.) The robot can self align nicely with a low goal by pushing it and subsequently was able to do well in programming competitions.
My summer Mentor dual Bobcat that was designed to hang had the slides all mounted facing the same direction. Here, because of power requirements, only two of the slide pairs were driven at a time. It needed two 393’s per lift stage to hoist the robot. It didn’t use a power expander, so we needed to limit the current. This design also used a 36 tooth drive and subsequently it took around 5 sec to move 18 in.
599D:
Fat robot after all tubes collected:
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