Mad Max Big Foot
Model of a vehicle from the “Mad Max: Fury Road” movie. Features 4×4 drive, steering, V8 piston engine, motorized radiator fans and crawler-type suspension.
Datasheet:
Completion date: 08/05/2024
Power: electric (Control+)
Remote control: Control+
Dimensions: length 44 studs / width 34 studs / height 38 studs
Weight: 2.268 kg
Suspension: 3-link triangulated
Propulsion: 2 x C+ XL motor geared 10.8:1 on all wheels
Motors: 2 x C+ XL, 1 x Mindstorms M, 1 x WeDo 2.0 M
This project was started by pairing LEGO Power Puller wheels, which are known for their enormous rolling resistance, with planetary wheel hubs to see what kind of performance can be achieved. It looked promising, so I added crawler-like 3-link triangulated suspension and proceeded to build a model of the Big Foot vehicle from the “Mad Max: Fury Road” movie, a movie that put plenty of vehicles on my “wish I could build it one day” list. In fact, I have already build a model of the Peacemaker vehicle from the same movie back in 2015, so another vehicle seemed long overdue.
The Big Foot was relatively simple on the mechanical side, but quite challenging aesthetically. The chassis was in essence a standard monster truck chassis with 4×4 drive and 3-link triangulated suspension in front and back, and the only challenge was making it short enough – a challenge I didn’t quite manage, making the chassis around 10% longer than it should be in order to be able to connect the driveshaft to two drive motors. This was fortunately mostly covered up when near the completion of the project I switched from LEGO Power Puller tires to slightly larger third-party tires, whose size brought the front and rear axle closer together, at least visually. Steering was handled by a Mindstorms M motor directly, without gearing but via a CV joint that turned out to have an unfortunate tendency to fall out and get lost in the sand. Finally, because the outputs of the drive motors were located at the very bottom of the chassis, I’ve used a separate WeDo 2.0 M motor to run a V8 piston engine with a fan under the hood, along with two fans in the back. I had to use pulleys and belts to fit this motor inside the cabin, but that proved to be actually quite useful, as the belts acted as slip clutches in case the engine or the fans got jammed.
On the visual side, the primary challenge was insufficient documentation – there was not a single blueprint of the body, for instance. I found that the bodywork was based on the 1940 Didge Fargo, but just like with other vehicles built for the movie, it has been extensively modified, stretched and chopped up so that it ended up being nowhere near the dimensions of the original car. In fact, there was not one but two Big Foot vehicles built, one for high-speed sequences and one for close-up shots, and the were both build on regular monster truck chassis, but the action scenes got so intense that one of the cars actually got its body frame broken. It was also difficult to see all the details, for instance where it came to armament. For some reason the harpoon gun is shown in the movie front end center while the flamethrower is almost always obstructed by something or someone. Going through the movie scene by scene I found just a single scene, lasting less than 1 second, where it was shown close from a side. Some details were so small that I chose to omit them, such as pieces of dolls merged into the rear bumper, which can be barely seen in the movie and which would simply not be identifiable if built with LEGO pieces at this scale.
The bodywork required complex STUD techniques, especially in the front where I had to build large curved grille with a big rotating engine fan right behind it, and then there was the hood which had to be carefully shaped, thin enough to fit over the big engine and strong enough to be opened. I’ve decided to not make doors open, because there was no interior to see in the cabin, just mechanisms, and also because with that much snow the structural integrity of the body wasn’t great and having solid doors helped to keep the front and rear firmly together. The Control+ hub was located at the back of the cabin, with the indicator LED visible through a trans-clear roof section and it was possible to replace the batteries without destroying the body. The space inside the body directly behind the hub was hollow and only covered with tiles from the top. It was normally used to store excess cables, but when needed, the tiles could be taken off, the cables pulled aside and that created enough room to take the batteries out of the hub.
From the start, the model was being built with the LEGO Power Puller wheels installed, but towards the end of the build I came across third-party monster truck tires that could fit the same rim and decided to use them due to their more accurate shape and truly massive size.
To film the model, I have purchased tan and blue-colored paper backdrops but in the end I didn’t need them. I found an open sand mine not far from where I live and I was able to take the model there during a holiday period and film it. It was quite a spectacular location and I hoped that I’ll be able to use it again in the future.
