Bloodsport competed on the Discovery Channel’s Season 4 of Battlebots.
This was the first heavyweight anybody on Team Bots ‘n’ Stuff had built.

Tech Specs

Weight: 247lbs

Weapon: Overhead Spinning Bar
Weapon Weight: 52lbs
Weapon Material: S7 tool steel
Weapon Speed: 1800RPM (250MPH tip-speed)
Weapon Length: 47 inches (1.2m)

Drive Motors: 4x Short Magmotors
Drive ESC: Brushed Rages
Total Drive power: 14HP

Weapon Motor: 4x Scorpion 5025 Motors
Weapon ESC: Maytech 100A
Total Weapon Power: 20-25HP

Sponsors: VEX Robotics, UMass Amherst Engineering, University of Utah, Big Blue Saw, Fingertech Robotics
Design & Build Time: 7 weeks!

Location: Boston MA

Team Members
Justin Marple (captain, drive operator)
Aaron Lucas (weapon operator)
Griffin Tabor
Nik Buchholz
Rebecca Miles
Jordan Kiesel

Record
4-2
Black Dragon (Loss, KO)
Four Horsemen (Win, KO)
Lucky (Win, JD)
Breaker Box (Win, KO)
Uppercut & Railgun Max (Loss, KO)
Sharko (Win)

History

The idea of Bloodsport was born from a never-to-be-built featherweight, Deathstroke. Deathstroke was designed in late fall of 2018 drawing inspiration from Brutality and Icewave. I really liked the concept of an overhead spinner with a large bite and reach, but still maintaining the ability to self right. The circular base was chosen as a way to help self righting when using a pole — the chassis has to slide, so any sharp edge might catch on the floor!

When hearing from fellow competitors that the Battlebots application window was closing soon, I spent an entire weekend, without much, if any, sleep, putting together a heavyweight version of Deathstroke and an application video together. At this point, the very first version of Bloodsport was born, though, with a fairly different look. The original version of Bloodsport had an asymmetric aluminum bar spinner as a weapon!

It wasn’t until the end of January when I heard back from production, discovering I had been accepted as an alternate for Season 4! As joyous of a moment as it was to get a spot on the show, the amount of work ahead to put together my first heavyweight was immense. I of course called up all my old VEX friends I had competed with and against for years in the past. None of us (besides perhaps Nik, who had a lot of Beetleweight experience) had any idea how to design nor build a Battlebot, so we had our work cutout for us. The closest thing for me was my terrible featherweight “Mowferno”, which had gone 0-2 at AVC earlier that year.

At this point we had 6-7 weeks to CAD up, order, and build the robot for shipping, which is an enormously short period of time, especially when you don’t even know what a “magmotor” is when starting. On day one, my singular goal was to make something exciting, win or lose. It didn’t need to be good. It just needed to spin up, do something exciting, and make good TV. If it did that, we could take the lessons learned from the build and hopefully be invited back next season, where we could design a more competitive bot.

To accomplish this goal, we decided to try to make the design as simple as we realistically could. This ended up meaning a 2-piece chassis (base plate + billet structure), 4 identical drive modules, and a single plate that housed the 4 weapon motors. We had the ability to also remove or add up to 6 motors on the weapon, in case we discovered we needed more power.

There were ALOT of design-fires to put out through the process, but I think the biggest fire was figuring out how to get the chassis made. This was by far the most expensive and difficult piece to get machined, and we quickly discovered most machine shops in the US didn’t have a way of machining it, because it was such a big piece. After traveling to several machine shops and talking to lots of generous machinists, we finally found 2 suppliers that could machine it. One was a generous shop in California (in fact, only a ~20min drive from the Battlebots venue!) who was willing to machine it at cost for us. The 2nd supplier was from a site called 3dhubs, which networks machine shops across the world for one-off jobs like our own. In this case, they found a shop with a big CNC in China. In both cases, it cost us about $2.5k each to get machined.

As exciting as an experience it is to build your first heavyweight, I don’t envy those who are going through it! There are a lot of design decisions that have to be made in a very short period of time. And to top it off, be prepared to back those design decisions with tens of thousands of your own money, and hope it all works out :)

Our First Match

As an alternate going into Battlebots, we weren’t entirely sure when we would get our chance at a match. It was entirely possible, if all the primary bots were good, we’d go until the very last day before getting our guaranteed one match! But fortunately, if my memory serves me correct, we got our chance to fight on the 3rd day of filming, against a team from Brazil called Black Dragon. Team Uai!rrior is a team that has previously been very successful around the world at competitions like Robogames, particularly with their middleweight “The General”. We knew it would be a very difficult fight against a very good and experienced team, and our focus was again, win or lose, try to make the fight entertaining.

Flash forward to after the fight was about as good as we could have hoped. We got about one good hit in, but after that Black Dragon didn’t have much trouble bullying us around. On perhaps their 3rd or 4th hit, where they got under us, we had our weapon RX wire pull loose and thereafter our weapon stopped working entirely. It turns out, we managed to glue, tape, or zip-tie every single bot except for the weapon rx wire. Quite a dumb mistake, though, it probably wouldn’t have changed the result too much.

The most exciting, and perhaps expensive hit was of course when they rocketed us to the wall. I have fond memories with Aaron and Jordan in the hotel room that night, laughing our butts watching the replay of Bloodsport getting absolutely hammered across the arena. This hit utterly destroyed the interior of the bot. 2 of the 4 motors were totaled, and all the gearboxes bolts sheared from the impact. The chassis was also had a large chunk missing, though, we probably could have repaired it back to working condition if we had too. Luckily, we had a spare chassis, so we started to rebuild the entire robot from scratch again.

Three Days Three Fights

After the Black Dragon fight, we got a full day to pick up the 2nd chassis from the California Shop, swap all the electronics out, tap our the gearboxes with larger screws (and better support the magmotors) and a few other minor improvements. We quickly found out that we were going to have another fight (another fight!!) the next day against The Four Horseman. The pressure was on, since last fight, we relied on the Black Dragon to make the fight exciting and tv worthy. This time, we knew it was all on us this time to make bots fly across the arena.

Not long after that, we found out we’d have another fight the following day against Lucky. Wow! Three fights is a fantastic first season as far as we were concerned.

The Four Horseman fight went about as we expected, we tagged out each bot one at a time without too much of an issue. To be honest, the fight seemed really exciting in person, but when we watched the stream, we can see why it was demoted to the Science Channel. It was pretty quick and not quite as gruesome as the SOW vs Creepy Crawlers fight from the previous season. I think the TV takes the excitement value of each fight down by an order of magnitude — it’s quite unfortunate.

Later that day we found out we would have yet another fight the following day against Breaker Box. Three fights in three days!

At the time, both Lucky and Breaker Box were fights we didn’t really think we could win. As newcomers, our expectations were quite low, and we figured we might get a few hits in, but it wouldn’t take much for them to flip us over and for us to find out if our self righting pole would work (we never got time to test our self righting in the test box).

The fight against Lucky was probably my favorite. It had sparks, it had drama and it had wedges flying across the arena, what else could we ask for (maybe less dead weapon!). This is probably the first time we really saw some potential in Bloodsport. We were able to deliver hit after hit, without any hint of the stability issues that plagued other overhead spinners like Brutality and Tornado Mer. If you look closely too, you’ll actually see the top half of lucky’s wedge getting cut off during the match, wow! The power being the blade is pretty mind blowing, and to this day it’s hard to comprehend with my mortal mind.

After some fixes and weapon tuning changes (we had some overheating issues with our weapon motor controllers), the next fight against Breaker Box, which was another one of those “oh man we don’t really have a shot” sort of matches. They had this intimidating titanium anti-spinner wedge, that we knew we would have a really tough time getting around. As we were lining up to fight, to our surprise, they instead had their mild steel wedge attached. Immediately we knew we might actually have a shot, as there were some serious edges along the wedge that we could catch with our weapon! All we would need to do is come in from the side and get a few hits in and surely it’d pop right off. And sure enough, that’s exactly how the match played out. Very fortunate for us, though the Breaker Box team later admitted they underestimated our weapon.

Playoffs

So if you’ve been playing along, we’ve now gone 3-1 in the season, beating Breaker Box, Lucky and The Four Horseman, and losing to Black Dragon. As a team who had only won a single match ever in our combat history, it’s safe to say we were quite thrilled with this result. And now we’ve found ourselves fighting for a top 16 spot! After a few days of rest, we got the news that we’d be facing off against another team from Boston, Uppercut, and a team from China, Rail Gun Max. All 3 of us were newcomers to the Battlebots scene, so it was geared up to be quite a fun match.

This ended up being the match were we had our spectacular hit where we either OOTA’d ourselves, or Rail Gun Max OOTA’d us, depending on who you ask. Has there been a bot that has managed to yeet itself out of the arena like that before? I’m not sure, but as disappointing as it was to lose our shot for the top 16, at least it was in a spectacular fashion.

After the fight we got to check out the damage and woah did we mess up Rail Gun Max on our big hit. Both aluminum bars (which must of been at least 1” thick?) were severely bent out of place. We never really got a chance to go after Uppercut, but hopefully we can get that rematch sometime in the future :)

The Shark

After getting knocked out in our top 25 rumble by getting booted out of the arena, the bot actually suffered almost no damage, besides a slightly bent self righting pole. So, we had a relaxing few days waiting for a grudge match and watching the playoff’s play out.

As production went through trying to pick out grudge fights, we actually got cycled through a few different opponents. It was something like, Captain Shrederator, Tantrum and End Game, before we finally got paired up with Sharko, who enthusiastically accepted the grudge match until he walked over and verbally said “oh no!”, when he saw what Bloodsport was.

The match was a fun one and Ed is a great sport. You can find the fight on Youtube!