Freshman Combots are CRACKED

Finishing out the spring semester, Freshman Combots has been hard at work on CRACK V2, our mecanum drive hammer/axe bot. As of this post, we’ve competed at two competitions with our robot: NHRL January New Bots, and Robobrawl 2024. We placed 5-8th at NHRL, and 5-6th at Robobrawl.

The picture™.

Competing at NHRL New Bots was a very interesting experience. Our first matchup was against Mr. Roper, a dual hammer-bot made of hardware store components. While we were confident going into this fight, we had an unexpected failure. Prior to the fight, the bot worked perfectly in the text box, yet, when we swung the hammer in the actual arena, the bot immediately died. Opening up the robot revealed that our main power switch had desoldered itself and was merely being held on by heat shrink. We quickly remedied any electrical issues and prepared for our next fight. Fortunately for us, our opponent, Kaizen Spirit, completely self-destructed in their previous fight and had to forfeit. With this “victory” we were in the Prime Time bracket! Our final matchup was against the terrifying British drum spinner, Nitro-Oxide. While this was a tough opponent, we were very excited to push Crack’s limits. Unfortunately, at the start of our match, we made a driving mistake and directly bounced into Nitro-Oxide’s drum. At the same time, the output pinion of our hammer gearbox slipped, and we were unable to self right.


After NHRL, we returned to UIUC and were determined to fix any remaining issues. The slipped output pinion was welded to the shaft to ensure it would never slip again, and wheels were mounted with more loctite to prevent loosening. We also resoldered many portions of the wiring harness to ensure it would not fail. Lastly, the robot was tested multiple times outside, checking that the robot wouldn’t break before the event. We also swapped in the lighter weapon to meet the 30lb weight limit, and ran multiple self-righting tests to ensure the robot could unflip itself.

CRACK V2 punching holes in its predecessor in a weapon test.

CRACK’s run at Robobrawl at Day 1 went off to a flying start. In its first match against Howard, we punched a hole through its soft, pliable sheet metal top plate and caused a LiPo fire.

Fire department got called after our first fight.

In its second match, we eked out a simple win against Brett Bot, by sniping their power switch hole and turning off their robot from the inside.

Crack and its hammer stuck inside of Brett Bot.

After this match, we had some small electrical issues (we were once again grounded to the frame), and we also had some bigger mechanical problems.

Robobrawl Day 2 was a lot rougher for CRACK. Our first match of the day was against Goose, whose strong drum and sharper driving led to a knockout.

Poor driving caused us to get punted out of the arena.

Our second match was against Apollo, who broke our weapon motor (again) and led to a tap out, as we were upside down and couldn’t self right. We however did participate in the rumble, which was a fun time, as we were hammerless against 4 other banged-up robots.

Looking towards the future, we have recently been invited by the University of Cincinnati to form the Midwest Collegiate Crusaders. This team is set to compete at NHRL’s June Teams event. These past two events have taught us a lot, and we’re always learning more with each fight. Freshman Combots forever!