While the final iteration of our 2019 hatch manipulator worked very smoothly, the first version… didn’t. In addition to requiring perfect precision in lining up and only sometimes actually grabbing the hatch, the top plate just looked very much like a diagram of a uterus.
The “silliest” prototyping I’ve ever been involved with came during Ri3D in 2015. If you’ve ever needed somebody to talk you out of forming an Ri3D team, just watch The GreenHorns playlist from that year. The GreenHorns were a lot more effective in the following years… but the first year was absolutely BRUTAL.
The “silliest” prototype from that year was probably the claw mechanism we did…
I can’t find the videos but I have a couple photos.
In 2013 when I was mentoring FRC 11, we had a pretty cool corner-climber design that never made it onto the field. I thought it looked like a caterpillar climbing and people ended up calling it the “Drostapillar”.
Instead of doing functionally three “pull-ups” to climb the pyramid like most other climbers were doing, we wanted to put a mechanism in the belly of the robot that was a linear drive right up the side of the pyramid. Two belts, each with 14 polyurethane feet riveted to them, would engage the corner rail of the pyramid and drive straight up. We pushed for this concept because (for the same motor count and gear ratio) it would climb twice as fast as a team who had to extend and retract an arm every rung they climbed.
We custom molded a lot of shapes for polyurethane rubber feet and ended up with what was pictured in the CAD screenshot as the most effective at gripping the painted steel pipes which made up the pyramid. The pipe would enter and become interlocked by two “tracks” of these feet opposed at a 90 degree angle from each other.
This worked and was incredibly effective for climbing a plain round pipe, but had issues getting over the “knuckle” present on the pyramid every 1/3 of the way up. Having to disengage the feet that were trapping the pipe, get over the knuckle, and reengage the feet was the larger part of the challenge.
We had it all working up to this point during week 3 of build season when I had to go back to college and could only come for Saturday and Sunday meetings. We ran out of effective time to solve the problem of getting over the knuckles during build season. This was still in the early days of bag and tag so teams weren’t so effective and agile at iterating major mechanisms onto their robot after build season ended. We all kind of agreed it would be too big of an issue to solve during competition season so we stuck with a simple 10 point climber all the way through champs.
I still don’t think it was “silly”! It would have worked given more problem solving time. Of course, @SJaladi and @Libby_K would probably argue that my bar for what is a silly idea is a lot different than most…
Each arm pivoted near the back and each wrist pivoted near the green wheels to conform to the cube. 60% of the time it worked every time. This was probably the 5th or 6th major intake design we had tried.
2 minutes into the drive team testing it and the whole thing exploded upon contact with the switch.
I’ve looked everywhere I can think of. Google was much worse at archiving everything you say, do, or take video of back then. I know there was some video taken but it might have been lost forever five cellphones ago. If I find it I’ll post.
When we used the 2018 robot to play Deep Space, testing whether a ramp would get it on Hab2 (the non-prototype would have swung down). I can’t find the video but 1st attempt the ramp broke off. 2nd attempt with extra strength it bottomed out on the back bumper.
I’d expect there are enough stories of abandoned 2013 climbing mechanisms to fill their own thread. Ours had four pairs of hooks for climbing the corner of the pyramid. In theory it worked something like this, with springs on the hooks so they could fold down as they passed the bars.
Unfortunately, we never found an effective way to deal with getting the rest of the robot over the two bumps along the corner rail. It was also not an easy thing for the drivers to align from 2/3 of the way across the field. We kept trying through our first event, but ended up removing it before our second.