Check out this fight in BattleBots World Championship VII (marked “Season 8” on most platforms), Episode 18.

After a big knockout of Skorpios, HUGE finds itself in the Round of 16 for the first time since World Championship 4! Way back then, MadCatter was a rookie hammer-robot with lifting arms, mostly attending as a practice run for their eventual appearances on the Chinese robot fighting show “King of Bots”. Originating as a spinoff of the WAR-Hawk team, MadCatter has become a legend in its own right both inside and outside of the arena. This was MadCatter’s first time in the Round of 16 as well, after Round of 32 losses in WC5 to Tombstone, and WC6 to Black Dragon. They’re very serious contenders, with a ton of power in their weapon and a configurable strategy with the lifting arm… but they’re also a normal short vertical spinner, who cannot reach the body of HUGE! MadCatter is riding a 3-2 record up to this point, with regular-season wins over Whiplash and Big Dill, and a 1st-round underdog victory in an amazing fight with Claw Viper.

With this match, HUGE will be facing a normal small vertical spinner for the first time since 2021’s fight against Riptide. And considering how unfinished HUGE was in that fight, really this will be our first anti-meta vertical spinner fight at full power since 2019’s match against Hypershock. When strategizing for this matchup, we realized that we really didn’t have anything specific planned. It had been so long since we’d actually needed to consider fighting a vertical spinner, that we had to step back and really think about our strategy and make sure that it was still compatible with 2022, rather than 2019.

We ultimately set up HUGE in a very normal configuration for this fight, with our S-blade and UHMW wheels. But we also made the addition of some small tegris chin-guards for the off chance where MadCatter bounces upwards during the chaos of battle. We spent a while thinking and rethinking, and ultimately figured that this was our biggest risk. These were thinner than the chin-guards run against Uppercut, but still hopefully enough to catch a single stray hit if necessary.

MadCatter on the other hand made a lot of modifications for this fight, understandably! Modifications included thick steel top plates, a weapon pulley guard, and a new barbed harpoon (“HUGE-poon”, in their words) mounted onto the end of the lifting arm. There was also a flamethrower duct taped (!) to MadCatter’s lifting arm, with a lithium battery duct taped (!!!!) right there to power it.

MadCatter is a fast and aggressive robot, and we wanted to combat that as best as possible. While HUGE would never have the agility to chase down a robot like them, we came up with the idea to box rush them right off the bat. The hope was that this could get them on the back foot early, and driving defensively rather than picking and choosing when they want to engage with HUGE. Plus, it would show aggression to the judges, in the case that the fight went the full 3 minutes. This somewhat worked, with a quick swipe taking off one of MadCatter’s three top plates. An exchange back and forth cost HUGE some wheel chunks, but we scored enough hits to fully disable MadCatter’s weapon. Chunks were flying, the flamethrower exploded, a light got broken, this fight was turning out amazing. A few hits later, their lifting arm went flying as well! And suddenly, HUGE’s blade came to a sudden and abrupt halt. This was less amazing.

It’s pretty widely known the HUGE doesn’t have the most robust backup plan for when the weapon fails. While most “normal” robots will have a wedge, or some other way to push and control an opponent, HUGE just is… HUGE. In situations like this, we switch to a plan of gently (yet aggressively!) tapping the opponent with our support legs. Not only is this literally all we can do, but it also serves to potentially free up a jammed weapon blade. Given how abruptly the blade stopped, and stayed stopped, we knew that something must be mechanically locking it into place. With four weapon motors and two separate electronic systems, there aren’t a lot of ways that it could have electronically stopped all at once. (And in response to the TV Edit, no we were not “conserving” anything).

After a rather boring second-half of the fight, and a few spinups cut short with further lockups, the fight mercifully ends…. at the exact time that the blade spins up? And stays spun up?? And to full speed too??? Not intentional, but very conveniently timed. We settle in for a long wait for a tense judge’s decision. Unanimous decisions for…HUGE! We did it! We’re heading to the Top 8!

It is dangerous to sneak up on a cat from behind. But it’s nice when you can take off someone’s top plate in the first 5 seconds of a fight.

Both robots were driving at maximum aggression, while our weapons worked at least.

With the top plate off, we began alternating upwards and downwards hits, fishing for a fight-ending blow. Sadly with the weapon failure, that hit never came to fruition.

A staggering lack of weapon motion blur.

You can see where the weapons impacted each other, which served to break some of the tooth off of MadCatter’s spinner. Also the remains of the (still-working) lifting arm/harpoon.

Looking like a hockey player missing a tooth, but hey, the wheel still turns! This was the first big hit of the fight on the wheels.

And this was the final hit from MadCatter’s weapon. Seeing each individual bite of the tooth is amazing.

The pressure was on now to sort out whatever broke the blade during this fight. Readers may remember that HUGE suffered a major failure of the weapon bearings while fighting Blip. At the time we attributed this failure to primarily an unbalanced blade, which created an oscillating load into the axle. This cooked the bearing, melting it to the weapon axle itself and turning the whole inside of the bearing to powder and melted goo (a phenomenon called “galling”). With the smooth surface long gone, the blade spun slower against Blip by the end of the fight, but it still turned.

What happened here however was a bearing failure of a whole different breed. Instead of failing broadly due to vibration, there was only a thin stripe welded to the weapon axle - a location directly underneath the blade within the wide hub. The stripe was so tall that the weapon could not be slid off of the weapon axle as-normal. The entire axle had to be removed from the robot, and the hub disassembled in-place opening like a clamshell.

We think that the bearing was damaged when MadCatter punched upwards on the tip of the blade early in the fight, and it slowly galled and built up enough material in the center to lock the blade. This early hit also twisted our blade, so it was clearly a lot of energy! As the time passed, the bushing would cool down, allowing us to spin up intermittently. As the blade shifted back and forth on the axle (due to HUGE driving around), it would catch this strip of welded bearing material, heat up, and lock up suddenly. We were fortunate that the blade came to rest in a free position at the end of the fight, allowing us to spin up and show off to the judges.

The inside and outside are supposed to be smooth…

Our next steps obviously were to sort out this issue, and prevent it from happening ever again. When showing off the axle and asking around the pits, a number of people pointed us in the direction of Martin Mason himself for a good knowledge of bushing materials. It turns out, they were right! In a great testament to the friendliness of the BattleBots pits, the MadCatter team took time away from prepping for Battlebots: Champions 2 to help us better understand our weapon bushings, and what we would need to do to survive future fights.

When Battlebots teams use bushings as weapon bearings, we know that we’re operating outside of the rated specifications. It’s a tradeoff, where they experience more resistance while spinning (creating heat), but can survive larger hits than bearings. All of these bushings are rated for a maximum of 30 revolutions per minute, which we tend to exceed. No Oilite-style bushings are designed for the high speeds of BattleBots weapons, but we learned that the “High-Load” style (chosen newly for 2022) are particularly prone to this style of galling when they fail. While the normal-style Oilite bushing is less hard and less robust, it can ultimately survive damage without galling the axle and locking up. Whenever possible, we want to choose parts that will fail without causing an entire system failure, so we knew that the change must be made for future fight(s) against similar vertical spinners. From here on out, this will be an every-fight consumable, but hopefully something that won’t stop the blade turning! Just to be certain, we took HUGE to the test box for a full 3-minute top speed spin test, and crossed our fingers.

With no damage to the axle, we felt ready to fight Witch Doctor! After 5 years at the BattleBots level, to reach the finale episode of the show for the first time is a massive achievement, and a great reflection of how hard the entire team worked to improve HUGE. Win, lose, or draw, no outcome from this point onward would lead to disappointment. But there’s no time like the present to keep the momentum rolling!

Thanks to HUGE’s sponsors, Mouser Electronics and TTI, Inc. Whenever you need electronic components next, either for hobby or professionally, remember that Mouser and TTI make it possible for HUGE to compete at Battlebots. We couldn’t do it without them!

If you’re interested, also check out our merch store to pick up HUGE gear, or your own pair of angry eyes!

Photo Credits: Dan Longmire, JCRB Photography