Bone Dead Robotics

Though the NHRL February event came before Motorama this year, Motorama always holds a special place in the annual robot calendar. Long before NHRL, Motorama was the premium eastern U.S. robot event and for a time was the largest event in North America, potentially the world. It was where I first observed the robots close-up and now, after 15 years of competition, it is where my best robots return to for testing. Let’s see how it went this year!

Pseudo-Return of Demogorgon

Astute followers of the team will look at this robot and notice that this is very different from expected. Demogorgon has historically been a undercutter and that goal is still largely true, but reality often has more wrinkles. Due to Motorama’s registration beginning back in November, Demogorgon was signed up as I hoped to make a new version for the year. Fast forward to January 2025 where it was clear that the also-registered Phenomenon was going to consume resources after what happened at the NHRL Grand Finals. Since the October NHRL Mind Flayer chassis was still largely undamaged from its one fight so I decided to repurpose it. The only real difference from this machine was the use of the same 4520 hubmotor cores that were used in Phenomenon at NHRL Finals where the center shaft was end-tapped. Ideally the beefier center motor would provide more consistent startup torque and hopefully longer fights. A bit of work was done aesthetically to see how the machine could be re-imagined to fit the new monster theme, but ultimately it was kept as a more simple call-back to its predecessor with the name being printed in green TPU and glued to the top plates. UHMW blockers were attached to the top plates directly above the batteries to provide a bit of protection in a machine that largely relies on the weapon for offense and defense.

The last big change to Demo was the implementation of ELRS. After the woeful radio issues of February NHRL it was time to make the switch. After a bit of issues with ELRS module not docking fully in my radio, the receiver settings were fairly straightforward. Ultimately there were no issues with the signal during fights so I was pleased. Though Phenomenon still ran the Hitec Optimas, which also had no issues in the past, the smaller size will be make these a very option to try next.

Phenomenon Upgrades

After the destruction of Phenomenon at the hands of WarHard XXL it was time to update the machine. While Vorion will remain fairly consistent in 2025 with some but no extreme changes, Phenomenon was going to be far more dynamic as the hubmotor system provides ample weight to upgrade and streamline the system.

More in-depth analysis will be provided on the year-end page, but here are the primary goals of the rebuild:

• Move the lifter gearbox internally
• Beef up hubmotor mounting through use of 1/4-20 mounting hardware and 5/16-18 through-bolt

To achieve the first goal was relatively straight-forward as the robot only needed to increase roughly an extra inch to accommodate it (you can see the difference on the top plate in the region not covered by the vinyl graphic). By increasing the width, the chassis is now wide enough to fit the battery on either side. Since the lifter gearbox is about the same length as the battery, this means the battery can switch to the “name” side and allow the lifter gearbox to move down in the chassis. Through the use of a simple #35 chain 1:1 reduction using the 10T 1/2″ hex bore sprocket from Andymark, the arm remains in roughly the same position with the use of a support block and by tapping into the central rail. The support block was originally prototyped in Nylon but the final version was made from machined UHMW.

While simple, this does weaken the arm’s direct strength as the Andymark Sport 57 gearbox has a very beefy output so it took hits from other robots without failure. By contrast, the 5/16″ shoulder bolt (with a 1/4-20 thread) was not only far smaller but due to the top plate being fairly unsupported in that corner (all of the retaining bolts are only held by the outer rail and drive gearboxes) it had high chances of bending. I’m skeptical of its strength, but since the robot had to be machined in China and assembled before Motorama I had to go with what could work for the time being and revise it later. The use of a 1/2″ hex bore and tight area to apply certainly made it tricky and future revisions will certainly need to be clever.

As for the hubmotor, the change was fairly simple as I only had to modify the endcaps to a larger thread, and bore out the shaft to accept a 5/16″ through-bolt. The base function was unchanged.

Event Prep

After a trip down to the Hive there was some issues with the weapon systems (foreshadowing) but the robots seemed largely functional. In Demogorgon the center shaft broke loose from the stator due to poor spread of the 680 retaining compound. Though one part of the shaft was coated, a large portion of the shaft was uncovered allowing it to break loose. Fortunately it was caught before any long-term damage was done, but clearly more attention would need to be paid on how it was applied in the repair.

In Phenomenon, the anti-horizontal version worked well but the anti-vertical version had issues spinning up which would be revised at home. Initial concerns were that the heavier 5/8″ H13 48HRC weapon blade was creating too much burden on the motor/ ESC combo causing issue with startup. In the anti-horizontal’s functional assembly, a Sequre 200A ESC was controlling the robot and seemed to be fine whereas the anti-vertical version used the same Sequre 120A ESC that was in the robot after Finals was in it. After swapping to a new 200A version everything seemed alright (foreshadowing).

Competition

After scoring a pit spot, it was nice to see the little upgrades NERC made. The big thing was the arrival of two new cages of the same construction: one was used for the 3lb competition, the other was where the 1lb/150g tournament on Friday and the test box for the bigger bots on Saturday/Sunday. Thanks to everyone on the team not only for these cages, but for even more little upgrades that I didn’t capture!

Demogorgon

Demogorgon went 0-2 at this event though for understandable reasons. Its first fight was against Junkernaut where the hubmotor did prove its worth right up until it ultimately seized up. The thinking was that the chassis wasn’t stiff enough to fully ensure concentricity so as the blade struck something the assembly would wiggle just enough causing the stator to hit the magnets and kill the weapon. Though the rest of the robot endured well, I ultimately tapped out to avoid potential damage to the main body which could hit the battery. After the fight, to my astonishment, Demo actually managed to hurt the belt on Junkernaut and leave only 1/16th of thickness of it left! Though it likely came from the pulley rubbing against the serrated aluminum baseplate, it was possible if I held on long enough it may have forced a Judges’ Decision but ultimately I was content with the outcome. The second loss against low fork bot Spike Tyson also came from the weapon seizing up. Funny enough, the slight offset between the axis of the wheels and axis of weapon meant the robot had to lean forward to get the blade low enough to get a shot on ST otherwise it would drive right under the blade. This also meant lots of back and forth thwacking action which ended up killing drive by the end of the fight due to likely very warm ESCs. Though it will need some upgrades, the robot proved overall quite durable so it could certainly return in the future!

Phenomenon

Phenomenon had a very disappointing start to the day. Despite successful testing, the weapon didn’t spin up at safety, already putting the robot on the backfoot. Based on its behavior there were two possible failure modes:

• the motor/ESC had lost phases and could only barely rotate the blade with no real power behind it
• the internal TPU sleeve around the motor’s rotor was slipping and the motor was just spinning internally (though imperceptibly)

Sadly there was no time to tear the robot completely apart so it had to run as-is. Fortunately for the two fights, against EXP-030 (a ring spinner) and EF5 (a shell spinner), Phenomenon’s wide wedge and general structure strength allowed it to simply reflect the opponent’s damage back allowing them to knock themselves out quickly. In fact, with the tiny amount of energy in the sad weapons, I was able to use a combination of that and the speed of the robot to invert EF5 just before it spun up! In the end, all robots are control bots.

After some test with the multimeter, it was clear that the phases of the weapon were not dead as the resistance was low (thereby showing connection). The Sequre 200A was also swapped out with the Rhino 80A ESC as it was a known quantity that still worked when bench tested. The last guess was to disassemble the hubmotor itself and slather the inner ring with super glue in the hopes that it would create enough friction on the ring to get it moving. It seemed to work decently in the test box, though I could tell it still wasn’t too happy so any real energy transfer would likely kill it.

Phenomenon v Ammonoid

It was definitely a rough fight. Though Phenomenon was faster than Ammonoid, as evidence of it controlling the fight after the big hit, I would say it was already a bit doomed. Even with the weapon in play I’m still a bit skeptical of how the reach and front geometry would have allowed for positive interactions. I’ll explore this more in the next section, but it did inspire some good food for thought.

Phenomenon vs Pepe Silvia

The last fight for Phenomenon at this event was a rematch with Pepe Silvia. Since I had decided to register Phenomenon for the March event instead of Vorion, the primary goal for this fight was to preserve the robot. The weapon still didn’t work despite best efforts so it was going to be a driving game.

The fight was likely boring for the audience outside of one big shot to the wheelguard/edge of front wedge which threw it against two walls before bouncing back down and continuing to drive. The efforts to remove all catch points on the top of the machine worked perfectly as more than once Phenomenon was able to glide under Pepe without sustaining damage. If the weapon worked, there’s a fair chance it could have eaten away at the plastic legs and avenged Vorion’s loss at June Teams.

Ultimately Phenomenon lost on JD due to the only big moment of the fight being Pepe throwing it into the wall though one could argue for control on my part. This was a good outcome though as this fight still let me test tactics for Pepe, preserve the robot, and give Luke a chance to find issues with Pepe for the next round. Even if I did win I would have had to forfeit to Deadrise as the lack of weapon would make it impossible to be competitive.

Motorama ends for Phenomenon at 2-2 which is pretty good for a lack of weapon!

The Meta Confirmed

It’s no secret that the vertical meta is a strong one, but this year’s Motorama was a very strong display of this shape’s dominance. In addition to Phenomenon, Synthesis 30, and Pepe Silvia (which is just a very weird vertical spinner) the arrival of Ammonoid (its predecessor was Nautilus), Overlord, and a newer Deadrise. Fundamentally, all 6 machines mentioned here (which also happened to be the top 6 at the event) have a similar goal with 5 of them being generally the same shape. This scenario, especially in the case of Overlord and Deadrise who even further overlap with Phenomenon, acted as a very dangerous but very critical mirror. Much of the goal of sharing details about Phenomenon and the rest of the team’s progress is to inspire others to iterate on the idea and innovate it. While it hurts me in that the rise of these machines likely means higher difficulty for my own success in a given event, it helps in the long-run that as I see others iterate in a way I hadn’t done I can add some of those aspects to my own machine with my specific twist. It’s that mutual iteration that ultimately has driven all machines long before Phenomenon and will long after it.

In the case of Overlord and Deadrise I’d say both machines have two fundamental differences to Phenomenon (excluding lack of lifter):

• Bigger blade
• Wider stance

Reach has always been an issue with the Phenorion line that I constantly consider. Other tall verts such as Emulsifier and Synthesis 30 have proven the importance of being able to outreach your opponent, but it’s also been clear that merely having a bigger blade doesn’t solve all your problems (Vorion defeating both Ripperoni and Catalyst XXX has proven that a bigger blade can actually be used against you). While a bigger blade does help with reach, the gyroscopic procession a tall blade creates is directly opposed to the control aspect of a robot. This difficulty only increases as even increasing diameter one inch only results in a half inch reach increase (diameter vs radius) while dramatically increasing energy (1/2MR^2) which then correlates to gyroscopic procession. In short, a bigger blade alone can’t be the only solution as eventually you will be unable to drive well enough to use it.

In direct response to this, a wider stance helps. Overlord is the widest machine at the event which directly countered it having the biggest blade. It handled very well so the physics can’t be ignored, but with width also comes issues such as defense against massive horizontal spinners like Chonkiv. The Phenorion shape has proven quite good at resisting horizontals as it allows for very hefty defense and to increase its width dramatically would make hosting a thicker wedge even harder.

Yet as Overlord and Deadrise carved their way through the event, it was clear that how you brace yourself and guaranteeing a weapon hit was critical. The bracers on the front of the robot have been good to keep the robot stable, but its also clear that out of many if not most of the Phenorion losses to other vertical spinners they have been the first areas to be damaged and limit weapon interaction. This will have to be evaluated before the March event.

That concludes the Motorama event report! Check back for more event reports and check out the robot’s year-end reviews!