Demogorgon-2021

The robot begins very simply with a base.

Thanks to my employment at Terrapin Works’ Instructional Fabrication Lab as part of my undergraduate studies, I was able to very rapidly waterjet most of the main structural components. The drivetrain is based around 20:1 Wang gearboxes paired with 1800kv Proprive 2836s. The weapon is driven by a single 650kv Propdrive 4248 motor on a roughly 1.5:1 reduction to the blade. Many of the components directly came from older robots Atrocious and Remedy which allowed for very rapid prototyping. In this first design, the goal was to use ~4in wheels to keep the overall profile of the robot low. However, the bolt head that secured it tilted the blade upward which provided a strategic flaw going forward. In addition, the fork mounts became overly beefy and quickly pushed the bot overweight. For now the goal was to remove the forks and run it as a pure undercutter, but the idea of them has always remained in the back of my head. The blades were acquired from Fred Moore of JACD/Valkyrie/Omega Team and I’m sure even more after he retired his own 12lb horizontal spinner called DxDDT. Custom blades were also made in order to reduce weight as the bot quickly approached the weight limit.

February NHRL 2021

Once initial building was done, Demogorgon was entered into the February 2021 Norwalk Havoc (my first event there!) and it had teething trouble. The single-point support for the weapon shaft meant that the weapon could wobble considerably as it tried to spin up and the small 6-32 screws into the nutstrip were far too weak to keep the Titanium snout on top retained. I underestimated how much impact the nose would receive so it was the first to go in its match against Kitten Mittens. Additionally, the nose didn’t provide enough protection for the weapon pulley so an extra large nose would be made in the next version.

The next iteration of the robot used the same drivetrain and chassis, but the weapon cradle was changed. The main difference for this design was the use of two levels to double support the main weapon shaft. This allowed more rigidity along the shaft and higher resilience against impacts. This is meant as a drop-in replacement so all of the dimensions and shapes easily slotted directly into place. Unlike the first design which was waterjetted, the new cradle is composed of top and bottom braces CNC’d from the Datron Neo machine that is also found in the IFL.

NHRL March 2021

After the cradle was retrofitted, it was taken to the March 2021 Norwalk Havoc event where it functioned fairly well. Though the drivetrain had issues as pinions kept slipping on the motor, the weapon proved itself to be very reliable and reached a place of high stability. The most notable fight it had was against Waterproof Sealant (Caulk). Though ignominious, the only real damage done was Starchild unplugging one of the drive leads. The other drive pinion did die randomly though so there are still lessons to build off from.

NHRL July 2021

Next up for Demogorgon was the July 2021 Norwalk Havoc. For this event the only improvement was to improve the snout. Ever since the weapon cradle was changed the snout had to go undergo a change, but I held off to get the best use out of the original Titanium sheets as possible. The new one is made from 2mm Titanium top with 3mm Titanium walls and is held together with 1/4-20 nutstrip. Though many robots aren’t going to be able to reach the snout, its one of the key places to upgrade since the first competition. Though Demorgorgon ultimately was knocked out by the BEC dying against Son of Kram, its victory against the scale model for the Battlebot Horizon and memorable KO against Troll Toll , the bot looked very strong going forward.

NHRL December Finals 2021

With all of the qualifying events done, the December Finals were on the way! The only change for this event was to create a new blade with a more balanced shape to it. It’s about 1in larger than the disk and the teeth should get much more vicious impacts.

The problem revealed over the course of the Finals is the concern around the wheels. Much like Tombstone, the wheels are open to other robots’ contact particularly that of other horizontals that are able to avoid the nose. This was revealed by the battles against Bobby (one of the few machines that could outreach Demogorgon) and against Ugee (the other machine .Admittedly these are the only two machines that could so uniquely challenge Demogorgon, but as more robots arrive and more diverse designs arrive in 2022 its best to be prepared.