HellTongue

Won most destructive bot in AIME Robotronica 2025

 

Demonstration

 

HellTongue is a staggered 4WD, box shaped vertical spinner. It uses impact resistant Tegris for the top and bottom plates and carbon fiber for the drive plates; all mounted on a thin TPU frame for structure. The rear wheels are much larger than the front ones, allowing for a faster gearing without a large weight increase. The staggered fitment also improves rear wheel grip and increases the turning stability. All of these factors make V4 much more controllable and responsive than previous versions.

HellTongue is also extremely versatile; coming with a dozen possible configurations. It has 3 different kinds of forks, along with a possible talon attachment, a wedge, a baleen, and 2–3 modular mounts on each side of the front to mount these items. It also has 3 different kinds of weapons, and titanium anti-hammersaw armor

This robot uses 1/4" AR600 for its main weapon and main/anti-drum forks, 1/4" AR500 for its hi-rake weapon, and 3/8" AR500 for its thick weapon. These weapons are mounted on a direct drive hub motor, attached to 3/8" thick UHMW uprights which are screwed into the robot from the front and bottom. It also uses titanium for its very long forks.

 

Change log:

V4.5:

• Changed weapon designs to have significantly less weight and gyro
• Side armor is now sloped to provide more protection to the drive system where is needed without significantly increasing weight.
• The carbon fiber drive plates have been made thicker to make them stronger; along with a second standoff connecting the armor and drive plate.
• The 4mm aluminum pin used for the configs has been replaced with either a short steel nut and bolt, or a longer titanium pin depending on the config used.
• The wheels, wedge mounts, config feet, and anti-hammersaw armor are now made of PEBA to save weight.
• HellTongue now uses a custom wedge aganist horizontals instead of the PBK wedge
• The magnets have been replaced with the old, much larger V3 magnets
• Small optimizations to the chassis:
  • Power LED better protected
  • more support & attachment points for the drive plates
  • config system moved lower to align the forks with the ground better.

V4.1:

• The config mounting system have been reworked; now using a 6mm titanium shaft to hold them in place, and a 4mm aluminum shaft to limit the travel of the forks.
• Little feet have been integrated in the fork spacers to prevent the robot from tipping forward when there is weight on the forks
• The carbon fiber top & bottom plates have been replaced with a specialized impact resistant Tegris that is stiff enough to withstand combat.
• Switched to a dedicated BEC unit to prevent random brownouts.
• Switched to AR600 for the main weapon and main/anti-drum forks.
• Forks have been made longer, and more optimized.
• Started using verified suppliers for all materials.
• Installed a power LED

V4:

• HellTongue has been converted from a 2WD robot to a staggered 4WD Robot.
• The electronics for the robot have been retrofitted to work with 6S batteries
• TPU Weapon Mounting system replaced for more lightweight, durable, and effective UHMW uprights with a titanium shaft.
• Weapon diameter increased to 125mm from 95mm.
• Drive motors have been replaced with 2006 motors to decrease weight and overall size of the robot.
• The armor has been made thicker, and can now be removed or replaced if damaged or not needed.
• HellTongue now fully relies on carbon fiber for structure; using the large top & bottom plate for horizontal stability, and two drive plates to keep the drive system in line and for vertical stability, with only a thin TPU frame to hold everything together
• The config mounting system now sticks out of the robot to save weight; it uses two m5 bolts instead of a m8 bolt, and has 2 (3 if side armor is installed) places to put forks or other config items
• The new config items include:
  • Longer main forks
  • Very long titanium forks
  • Thick anti-drum forks
  • Outrigger forks
  • A Titanium wedge
  • A Baleen
  • Talons (installed with forks)
  • The Main weapon
  • A High rake weapon
  • A Thick smaller weapon (along with smaller uprights)
  • Anti-hammersaw top armor/Ti bottom armor

These can be combined to make many possible configurations.

• Switched to plastites from bolts and embedded nuts to attach the top/bottom plates
• Ceased all useage of 98A TPU
• Used smaller magnets to reduce weight

V3.6:

• The Bolts holding the top part of the uprights in place have been made stronger, as they were previously inadequate.
• The Shaft collars used for the wheels have been replaced by ones made for combat robotics to prevent them from being ripped off as easily. 
• Two small Tegris plates have been placed above the battery for extra protection.

V3.5:

• The heat sinks once used to keep the top plate screws in have been replaced with embedded nuts that are inserted into the 3D print halfway through, and then printed on top of. Making the screws much less likely to be pulled out. There is also eight of them instead of six.
• Small bolts have been added at the top of both weapon uprights to prevent them from shifting and potentially hitting itself during a fight.
• The carbon fiber bar has been replaced with a much larger plate to decrease flexing of the entire chassis.
• Magnets have been made stronger
• Both the side wedge armor and the wheel urethane have been made thinner to stay in the weight limit.
• Experimental configurations have been scrapped due to inadequate construction. New, better ones will be coming in the future.

V3:

• Armor has been significantly modified and redistributed to better protect vulnerable areas. The new wheel armor is to the side rather than the back to improve self-righting ability. It is also compliant and has strategically placed holes, so the chassis can still be printed all at once.
• The neoprene foam wheels have been replaced with cast treaded urethane wheels with TPU hubs for improved grip, They also have a compliant mechanism that grips the axle tightly; in tandem with a traditional shaft collar.
• The polycarbonate top plate has been replaced with impact resistant Tegris. Only one plate is needed, but multiple can be used if necessary.
• Magnets have been added to the underside of the chassis, held in place with a screw going through a carbon fiber stiffening bar that also helps with the structure of the robot.
• 95A TPU is now used for the chassis instead of 98A TPU, all other TPU components are still 98A
• Switched to the Repeat Vortex ESC for the weapon
• Switched to two individual drive ESCs for improved margin of error while soldering
• New configurations

V2: 

• Introducing Ring Armor! A way to increase the thickness of a TPU wall without increasing the amount of perimeter walls in your slicing software. Doubles the thickness of all armor from 6 layers to 12 with minimal weight gain.
• Switched to 2207 brushless drive motors to increase power and save weight.
• Dropped the S7 components in favor of AR steel parts.
• (With the exception of the weapon ESC.) Switched to Repeat Robotics for all electronics and motors.
• Added side forks to the sides of the main forks to improve flanking ability
• Added small ears to improve inverted driving control. (any bigger and the wheels would be off the ground.)

 

Version 4 of HellTongue is my overdue answer to the increasingly competitive NorCal beetleweight scene rendering previous versions obsolete. I have gotten extensive advice from the absolute best while making this robot, and I am hoping that it will finally get me my first win. V4 is a vast improvement over previous versions in all aspects.

Special thanks to:

Kinship Academy, for sponsoring this project. 

Sierra College Advanced Manufacturing, for water jetting the metal parts.

Sierra College Robotics Club, for teaching me everything I know.