Designing a Giant Fighting Robot

Written by: Dave Martin

Read Time: 4 min.

A recent tweet from PTC Academic regarding giant fighting robots stopped me in my tracks.

Ever since I was a kid, I have loved giant fighting robots (GFR for short). I was 5 when I first discovered live action where guys in suits fought over miniature sets like in Space Giants and Mechagodzilla. Here in the United States, we had cartoons like Voltron and Transformers, but I preferred mecha anime like Mobile Suit Gundam and Space Defense Fortress Macross (known as Robotech here). And now, a design team in Japan is building a life-size mobile suit Gundam.


GFR Design Considerations

If I designed a giant fighting robot, I’d base it around the same three primary requirements of the M1A1 Abrams tanks I served on in the Army. Those tanks had to support mobility, firepower, and survivability. Driven by those requirements, here’s how I’d approach the design:

  1. I’d define the product structure. Given the mission of these giant fighting robots, I’d take more of a middle-out design approach, rather than a top-down approach. I’d figure out what features and characteristics my GFR would have, where components needed to be located, and then I’d design around those constraints. My design would center around figuring out:
    • The weapons systems. This is similar to the US Air Force’s approach for the A-10 Thunderbolt. The aircraft was designed around the seven-barrel Gatling autocannon. I’d decide what guns, missiles, lasers, and swords the GFR would have. Or, maybe it could launch its fists as projectiles. Then, I’d base my design around placement of those weapons.
    • How it gets around. I’d decide if the GFR is a walker or a flyer. Maybe it can make short leaps for power attacks. Or, maybe it can transition between walking and flying modes. My decisions about its movement would impact the design as well.
    • What powers it. I’d identify the GFR’s energy source and where those components need to be located on the robot.
  2. I’d develop an engineering notebook. So much depends on structural analysis. I’d create an embedded PTC Mathcad worksheet. Engineering calculations would help me lay out initial envelope dimensions, as well as requirements for strength, power, and armor.
  3. I’d build skeletons. I’d create the initial geometry using the same middle-out approach I mentioned above. I would:
    • Define initial locations for any off-the-shelf components. And I’d create envelopes for major systems to be designed.
    • Use curves, datums, and surfaces to lay out the legs, torso, arms, and head, as well as mechanism interfaces.
    • Create surfaces for the exterior, also known as the outer mold line (OML).
  4. I’d configure the mechanism connections. Mobility is one of the fundamental aspects of the GFR’s design. I would need:
    • Pin connections for one rotational degree of freedom (DOF) joints like knees, elbows, and the waist.
    • Ball connections for three DOF joints like ankles, shoulders, hips, and head.
    • Slider connections for one translational DOF for the actuators that behave like our muscle fibers, expanding and contracting.
    • Gear connections to increase power distribution to the arms and legs for attack and defense.

If the GFR transforms between walking and flying modes, I’d need a bunch more mechanism motions. 

After I complete these steps, I would share the geometry from higher levels to components and perform detailed design work. During this phase, I would incorporate these additional factors into the workflow:

  • Real-time simulation. With a complex design like this that’s full of competing factors of weight, speed, and armament, I’d want to see the effect of design changes on my structural, thermal, modal, and fluid analyses as I make them.
  • Design exploration. I’d want to explore different design alternatives as I think of them without having to create and manage a series of copied files.
  • Generative Design. The Gundam should be optimized for high strength and low weight. Every pound saved results in better mobility and increased fuel efficiency. Generative Design harnesses Machine Learning to assist you to develop structures that are strong and light.
  • Augmented reality. For something this big, I want to see how it looks in the real world. After all, looks can be deceiving on a computer screen. Publishing my design to augmented reality allows me to visualize my Gundam in its actual environment.

Our fully functional giant fighting robot is now ready to defend Earth from invaders!


This was a fun design exercise. If you had to develop your company’s products from scratch, how would you do that given the advances in areas like generative design and additive manufacturing?

In product development, it helps to re-evaluate your processes and workflows from time-to-time to ensure you’re utilizing the latest technologies, like those available today in Creo Parametric 7.0.
Creo 7.0. The Future of How You Design.

Tags: CAD Retail and Consumer Products Connected Devices

About the Author

Dave Martin

Dave Martin is a Creo, Windchill, and PTC Mathcad instructor and consultant. He is the author of the books “Top Down Design in Creo Parametric,” “Design Intent in Creo Parametric,” and “Configuring Creo Parametric,” all available at He can be reached at

Dave currently works as the configuration manager for Elroy Air, which develops autonomous aerial vehicles for middle-mile delivery. Previous employers include Blue Origin, Amazon Prime Air, Amazon Lab126, and PTC. He holds a degree in Mechanical Engineering from MIT and is a former armor officer in the United States Army Reserves.