Dragon*Con 2011 Microbattles: RIP upChukk

Post date: Sep 5, 2011 12:31:04 PM

"...odds are good that your first robot will -- and there is no nice way to say this -- suck..."

So says someone who's been at this longer than I. Actually I had a pretty decent run for a first-timer.

First round vs. Melty-Bot

Win. Opponent was a wooden bot from the GaTech robot club. My spinner tore him to pieces, literally. I took a few chunks out of him early on and then he managed to get stuck in a corner. I turned my spinner on him in the hopes of knocking him loose but ended up dealing a final blow. (Dude, if you're reading this, I'm really sorry! I didn't realize it'd do that much damage -- I guess I turned the juice up a little high.) Swept his shattered remains off stage and that was that.

Second round vs. Misdirected Agression

Lost. This guy had a horizontal spinner and it delivered a beat-down. If I read the video correctly, he knocked out my safety disconnect on the first hit, leaving me without power.

Ours is the first match in this video:

Damage report:

  • Gearbox on one of the Beetle B16 motors separated from the motor, just like in practice (in the pic see the motor dangling to the left of the glare spot and above the red-white-blue wires; the gearbox casing is the circular piece below the wires)
  • One of the hex bolts on my spinner weapon sheared off. This is probably what put a hole in the roof of the arena.
  • Spinner weapon shaft bent. I expected this -- even had spare shafts ready to replace it but didn't since the spinner itself was hosed.
  • Mangled emergency disconnect. My weak(est) spot and he totaled it. This is what left me dead-in-the-water.

Frantic Patch Job

After the aforementioned beat-down I had my doubts I'd have anything left for the rumble, but I tried anyway. The biggest issue was the gearbox. Fortunately, MOST of the pieces were still in my case, so I carefully swept them out and rebuilt the gearbox. What I learned is that a 3-stage planetary gear will work okay (if loudly) if two stages are each missing a spur gear. Wow.

While I had the case open I removed the weapon motor and ESC -- no chance getting the weapon ready for the rumble, so may as well save my $70 motor and $50 ESC for a later 'bot.

I had a random piece of angle aluminum in my toolbox that was the perfect size to build a quick-and-dirty fence on my weapon protrusions. (That sounds dirtier than it really is.) It offered some protection to the remaining electronics and gave the 'bot some added stability.

Kudos to Brandon of Team Shrewsbeckistan for soldering me a new safety disconnect. I was now ready for the Royal Rumble!

Royal Rumble

Lost. Not much to report here, mostly because it was (predictably) chaos. One 'bot was made entirely of LEGO's, which ended up in pieces all over the arena after about 5 seconds. So most of us ended up stranded on top of LEGO bricks. I maybe had 30 seconds of movement (I'm being generous here!) before my rebuilt gearbox once again disintegrated and my drive motor was left dangling and twitching. In the end, I was still on stage with a couple other immobile bots and one mobile bot who was declared the winner.

Damage report:

  • Gearbox exploded. Again. No pieces found this time.
  • Wedge skirt ripped off, along with a large chunk of the Lexan "armor" to which it was attached.

Lessons Learned

  1. Thread-lock on the bolts that hold B16 gearboxes to the motor. So says the guy that beat me. (Thanks for the tip, dude!)
  2. Lexan is not armor, at least not in the thickness I used.
  3. There are some brutal spinners out there. Ponder how to defend against these.
  4. Use grade-8 (I think) bolts on my spinner. Hardware-store bolts are too soft and shear off at inconvenient times. (Thanks to the guy I was talking to in the pits whose name I don't recall.)
  5. Bite the bullet and buy hardened weapon shafts.
  6. Have a minion who can pay attention to announcements for me. More than once I nearly missed my bout because I was too focused on repairing, recharging, etc.
  7. Related to #6: bring a second battery (or, at least, quick-charge in place).
  8. Also related to #6: hack my transmitter such that the "mixing" switch is external (and doesn't require removing a battery and flipping a minuscule DIP switch). Or, remove mixing from the Scorpion ESC. In the end, it should take no more than a couple of seconds to re-configure my controller when switching it to a different bot.