Our ground speed (10 fps with a non-shifting gearbox) was too slow. We had more control than we needed for alignment, and not enough speed to get around defense. Pushing wasn’t as important as we expected.
Cable drive (climber) without “keepers” to prevent cables from coming off the pulleys when tension was lost.
On the other hand, we violated one of our normal rules and it proved NOT to be a mistake: We relied on gravity rather than active control to move, stack, and index the game pieces in the robot.
One mistake of our team was us mentors getting burned out trying to figure out a floor pickup system instead of investing those hours improving our loading and shooter on a perfectly capable cycling machine. If we had spent those hours we burned away on a floor pickup on improving our loader and shooter, we likely would have walked away with a blue banner or two this season.
Deciding to do all the aspects of the game. We underestimated the importance of an extremely accurate shooter and instead spent lots of time on a 30 point climber that sometimes, at its best, went to 10. Here’s a link to our robot’s info page : http://www.team708.org/current-robot.html By the way, at our most recent off season, Monty Madness, we took off the climber (after the event was over.) We hope to build a ten point climber by our next off season event MidKnight Mayhem.
Trouble shooting inconsistancies in our shooting. Our floor pick up was awesome but we failed to correctly diagnose problems with our disc delivery “bucket” that lifted them into the shooter mechanism. The inconsistent lift of this device lead to inconsistent shooting and jamming in the later season. We thought we had it several times but it would return after a match or two of minimal problems.
The unlikely source, an intermitant pneumatic cylinder. We have used cylinders on all our robots since 2010 and never had problems but these were long stroke with a “dainty” rod diameter.
The good leason, aquire game pieces and shoot quickly. Shooting 70% of 16 discs is better than shooting 95% of 8 discs.
Not having a solution for upside down Frisbees in your hopper before you get to Champs. Of course we lose our first match by 2 points with an upside Frisbee in our hopper. Then at the end of the weekend you realize you missed out on a 8-0 record and #1 seed because of the dreaded upside down Frisbee in your first match. But you can’t change the past so just keep moving forward.
Not designing the robot in CAD (we’re working on making that better for next year)
Spending 3.5 weeks prototyping and sketching designs. - I was very busy with FTC for the first part of the build season, so I wasn’t able to be around for a lot of those meetings, but I attended kickoff, and our post-kickoff brainstorm, and that went very well, but I came back over halfway through the build season, and we barely had a drivetrain! D:
Building a key piece (our hopper) out of acrylic*, which has a tendency to shatter and break.
Yes the bright orange polycarb looked very, very pretty (especially when we cut ‘FIRST Team 1912 Combustion’ to it) but we took a hammer throw to the wrong place and crack a part, got into some defensive pushes and broke off a piece, etc. Between our three competitions (Bayou, Razorback, CMP) we had four hoppers. Wedneday night of Razorback we were using hotel dollys to bring tool boxes up to one of the rooms to do maintenance. One of the favorite sayings of the pit crew and drive team / one of the most hated sayings by the pit crew and drive team was “Guys, lets change the hopper!” This did however, have a silver lining that JVN would appreciate: it forced us to iterate and therefore, with each event, our hopper improved. On our team, we had never really been able to do that; to test a piece in competition, notice that there could be improvements (like making the feeder slot larger so the human player can feed faster) and making those changes. I think that process helped our students learn to analyze machine features.
Or it might have more to do with the fact that OPR is not an accurate measure of individual robot performance. How much did you actually score per match and how did it compare to the rest of your division?