Bone Dead Robotics

MACRO February 2022

For the new year, I wanted to eliminate any grab points on the chassis and allot more weight to other areas and increasing the amount of filament perimeters to strengthen against hits. To do this, I rounded out most chassis corners as these were catch points other machines had hit during previous battle. The shape of the robot was largely the same as at the end of 2021. After a quick print on the Prusa MK3S it was easy to transport the components into a new chassis base. After adding longer wedgelets I confirmed the weight and it was all good to go for competition.

The competition itself was brutal and short. Either due to too low of perimeters, harder impacts or some combination of these things, Kerfuffle had its hardest outing yet. As competitors got better its difficult to assume anything is “easy” but the supposed upgrades I added for the fight should have resisted failure modes that the previous version seemed to handle very well. With the first time since its inception, Kerfuffle did not medal at a competition, ending a years-long streak. After a steady progression to this point, it was concerning to see this stark back track. While it would have been easier to simply revert to the previous version for stability, I ultimately wanted to keep moving forward as there were more ideas that I had in mind to try out.

Modularity

The next innovation of Kerfuffle design was to utilize a supremely modular base. After watching innovations across the combat robot world, I understood that in order to prepare against all different types of opponents, especially as a lifter, you have to optimize for it. With the Kerfuffle bases previously, the wide wedge body and forks were used in all configurations which was not optimal. Horizontal spinners hooked the forks from the side (as seen is the previous events’ damage) and would hook even worse if the forks didn’t fill the opening. This is especially true if the forks were extended. On the flip side of that is against vertical spinners where the edge of the wide chassis proved to be excellent catch points to launch the machine. While the size was helpful at times to control, the weight lost to the chassis size needed to be redesigned to protect the lifting arm which was the perennial weak point.

This new modular design was very simple, where all of the electronics are contained within a boxy structure with mounting holes to through bolt attachments onto. If not for the plastic restrictions, I could theoretically flip between plastic ants and full combat ant chassis; Ferocious and Kerfuffle could serve as each others’ spares if time was short and the damage was irreparable. It also allowed the integration of flexible TPU filament ( something especially allowed by MACRO) while still maintaining the stiffness of PLA+. This balance was critical as the PLA+ was not able to maintain the level of beating for a full competition straight. I also tried casting urethane wheels for this version but due to it being so heavy they were switched back to foam. The lifting arm was also narrowed, thickened, and printed at an angle to hopefully resist it being cracked off.

The TPU front forks were doing another service which was to make compliant wedglets! The idea was that the harder PLA+ is better at getting under the squishier TPU but the TPU base around the wedglet would better survive the impact and could be used to pretension the tip into the ground as a form of passive spring-loading. The only way to know for sure was to put it in the box!

MACRO April 2022

Despite a very stacked field, Kerfuffle managed to return to the podium! Kerfuffle had a very long day against some great machines, all of which showcased the durability of the TPU nose, but the PLA lifting arm remained weak as it split on the layer line. Hot glue tried its best to keep it going but to no avail. The spring loaded wedglets also only worked until beaten once. As soon as it was struck it would deform out of the way and because it is held by tension there was no method for it to be reset. This was extremely critical in matches against ground game machines such as The Captain which would eventually get a hit, ruin the tips, and cripple Kerfuffle for the rest of the match. By contrast, Ferocious’ basic wedglets would reset after hits since they would flop down to normal position.

Battlebots Side Quest

Before the year ended, I brought Kerfuffle with me to Battlebots 2022 filming as a way to pass the time. It met a little friend in MicroBlaze and they sparred for awhile! Its fun being able to enjoy the little things even with the intense atmosphere.