This MOC is inspired by Tim Cameron’s 700HP rig called “ShowTime”. It’s a one-off custom built rig made specifically for “Southern style Rock Bouncing” events. These machines are all about insane horsepower, near impossible climbs and pure strength. The chassis design uses over 60m of steel tubing as is often criticized as being ugly and “excessive”, but the design is exactly what keeps this rig together after repeated crashes, rolls and torque-driven rock bouncing.
The LEGO version is made to closely resemble the original at 1:10. It features a powerful driving and climbing ability from 4 XL motors, geared 1:3. It uses 2 SBricks for control and, just like the original, it includes 4 wheel drive, 4 wheel steering and 4 link suspension. During the outdoor driving, the tires gave excellent climbing traction over rock and loose dirt. The motors had no problem with torque. It was only the batteries that lost power very quickly with the high drain setup and the cold weather. The suspension could also benefit from harder springs in the front as the center of gravity is placed between the front tires and seats. The tires performed beyond expectation on the climbs, but did put strain on the single servo motor. The tread pattern having grip on the sides also makes them grip the body if there is not enough clearance provided when they reach steering lock position.
The biggest challenge in this build were the axles. 4 wheel drive and 4 wheel steering was a requirement, as well as a look that resembled the original. After several attempts to include the motors in the chassis, a compromise was made to have 1 L motor directly driving each wheel. This gave the “compact” look I was looking for but performance was disastrous. After finishing the build, I decided to restart the axles using 1 XL motor per wheel and a portal hub with 1:3 gearing. The results in the end gave good clearance and enough torque to overcome some steep rocky climbs.
The most exciting part of the build was the fully tubular body, in red! I knew that I couldn’t convert the colour scheme to blue, grey or black so I had to find 3’rd party hoses compatible with LEGO. The build ended using 3.5m of hoses, all cut to standard LEGO lengths. All the hose connections as well as the rest of the build was made using 100% LEGO parts.
Control: 2 SBricks
Drive: 4 XL (1 independent motor per wheel)
Steering: 1 Servo (4 wheel steering)
Batteries: 2 AAA battery boxes
Length: 60 studs
Width: 30 studs
Height: 28 studs
Ground clearance: 6 studs
Weight: 1.6kg (with batteries)
Tires: Interco IROK 1.55″ from RC4WD
Part count: Not determined
Instructions: Photo Sequence