A Hummer H2 SUT style truck featuring all-wheel dual-wishbone independent portal axles, 4WD, and a 4-speed sequential gearbox among other features.
About this creation
Propulsion: 2 x XL Motors
Steering: 1 x M Motor
Drive Type: RWD - 4WD
Transmission: 4-speed sequential with 1 x M Motor & custom stepper mechanism
Weight: 2.5 kg
Height: 21.5 cm high
Length: 55 cm long
Width: 21.5 cm wide
Extra Motorized Functions: RWD - 4WD selector with 1 x M Motor
The commercial branch of Hummer has been discontinued, but the legacy lives on… the legacy of gas-guzzling, oversized, expensive, indestructible off-road fun (no offense to any of you who may own Hummers). I retain all of this in my model, being my biggest, heaviest, most complicated, and favorite creation to date. It is also my longest project yet, requiring 1.5 months of work and 2 failed chassis before it. I decided to create this model after the failure of my 4 x 4 Toyota Style Truck, which had weak elements that prevented it from driving over obstacles, a transmission not containing enough speeds, and aesthetics that weren’t quite right.
This truck was built around a large studless body with two sets of parallel rails. The result was extremely rigid (especially with the internal elements added), relatively light, and provided enough room for the truck’s other components.
The transmission was the most difficult part of this vehicle to build. I knew from the beginning that I wished to create a sequential 4-speed transmission like the ones in my previous cars, but with a stepper motor that could turn both ways. After several cumulative hours of thinking and tinkering with my parts, I managed to create an M motor stepper motor that doesn’t damage the motor’s internal parts. The transmission ended up working excellently, and will probably become a standard for many of my vehicles. I will be posting pictures and instructions for it within the next month (probably alongside the ones for the CVTs). The final drive of the vehicle’s transmission speeds (not counting the differential’s 1.4:1 gear reduction) were as follows: 13.85:1, 8.31:1, 4.6:1, and 2.77:1.
The suspension was partially based off of Sariel’s independent portal axles that he used for his Hummer, except is used different parts that resulted in a wider wheelbase appropriate for this scale of car. The portal axle hubs contained a 1.66:1 gear reduction, which added torque to the system and reduced strain on the rest of the drivetrain. Because of the model’s huge weight, the suspension resulted in being very soft and responsive.
This vehicle also contained a RWD - 4WD drive type selector, controlled by an M motor and pulley system. The difference between drive modes wasn’t particularly noticeable, except when driving over a large object (4WD worked better) or when on high gear on flat
ground (RWD provided much more speed).
The car was the first of my models to feature a fake piston engine (shown in the pictures below), which was connected to the front wheel section and likewise varied with the speed of the transmission. I also included a manual winch, controlled by a knob in front of the passenger seat and connected to a worm gear. The worm gear controlling the winch ensured that it couldn’t be back driven, but also resulted in low winch speed and rather tedious operation. Locking doors were also included and are detailed by pictures below.
I am very satisfied with this vehicle. It had enough torque on the two lowest gears to drive over nearly any obstacle I threw at it, and was fairly fast on high gear, especially considering its weight and 7.2v power supply. The components of the drivetrain were built soundly enough that the motors stalled before gear skipping occurred. After this long and challenging project, I will be moving away from large scale trucks for a little while, having several other large sports car and small vehicle projects that I would like to build. For more detailing on the mechanisms of the truck, look to the pictures below and the transmission instructions coming soon.
This model was also my first to include my new mascot, the unhappy little guy shown above.
This set of photos shows the door opening mechanism from both the inside and outside. Once released, the door handle will remain in either the locked or unlocked position.
These next few photos detail the process of opening the hood. Take note of the piston V8, which is connected by a few gears to the front axle's gearbox.
A couple of photos with everything (hood, bed, and doors) open.
Shown here within my boring interior is the 16t gear that serves as the knob for the winch.
This is what should be the back row of seats. Instead, it played host to the transmission and tangle of wires seen here.
My first usage of working headlights in a model.
The elastic shown in this photo is for the purpose of hardening the suspension, which previously would squish down about 2 stud under the model's weight.
The elastic shown here, as said above, is there for the purpose of hardening the suspension.
These two images (above and below) show the mechanism for the winch.
Here we have a few poorly taken pictures of the unfinished chassis.