ZIL-E167
An ultra-small off-road truck. Features 6×6 drive, steering on first and last axle, full suspension and an engine bay.
Datasheet:
Completion date: 30/01/2022
Power: electric (BuWizz 3.0)
Remote control: BuWizz 3.0
Dimensions: length 37 studs / width 14 studs / height 17 studs
Weight: 0.971 kg
Suspension: pendular
Propulsion: 2 x PF L motor geared 17.1:1
Motors: 2 x PF L motor, 1 x PF Servo
Update: free building instructions for this model’s suspension unit are now available in the Downloads section.
ZIL-E167 was a Soviet-era truck prototype designed for the most extreme conditions, especially for Siberia and far north part of Russia. My LEGO model was an attempt in building it at the smallest possible scale while keeping the 6×6 drive, the steering on two axles and suspension.
I wanted to build an off-road truck with the LEGO small tractor tires ever since I first saw them, but because they’re relatively small, few trucks would be big enough to be motorized when built at a scale imposed by these tires. ZIL-E167 was one of these few, being an enormous truck in reality. I was able to shrink it to roughly 1/30 scale, which is actually below LEGO minifig scale, with 9 studs wide suspension units and 10 studs wide body. This was possible mainly thanks to abandoning differentials in favor if single gear wheels driven using worm gears from above and thanks to the axles going through these gear wheels not passing through any pin holes, but being locked inside 1×1 stud holes while covered by CV joints, which kept the axles in place. Another challenge was making the motors fit inside the body – as you can see on the work-in-progress photos below, every millimeter mattered. I was able to make them fit because the whole chassis of the truck was essentially just 3 studs wide.
The resulting truck was a little taller than the real one, in part because the real ZIL-E167 had no suspension and relied on big soft tires with central inflation system instead. I wanted to use a suspension, and so I had to raise the body to allow for some suspension travel. Additionally the height of the motors and of the BuWizz unit necessitated making the body a little taller than it should have been. Still, the model performed pretty well, it was quite stable (up to 40° sideways tilt and up to 40° climb) and it had monstrous amount of torque (222 N.cm, equal to more than 15 ungeared PF XL motors). In order to speed the truck up despite the massive 24:1 gear reduction inside the suspension units, I have accelerated the drive motors, resulting in a total gear ratio of 17.1:1. The steering system wasn’t very efficient and had some play in it because of the many gears involved, but because the axles were so close together, it worked pretty well in the end. The lack of differentials wasn’t issue most of the time, except when trying to make a turn on a slippery surface such as ice.
The main downside of the model was modest ground clearance of just 2 studs, which I think is still impressive for a vehicle on wheels whose diameter is just 7 studs. While the real truck uses portal axles to increase ground clearance, I was unable to fit portal axles within the given width limit.
The model was quite a challenge to build, and the highly detailed body required many advanced SNOT techniques to build. Still, I have enjoyed it a lot, even though the small scale and the limited choice of orange LEGO pieces meant that I had to make some details using 3mm rigid LEGO hoses with metal wires inside them to keep shape. It’s not a technique I like and one I’ve always been trying to avoid, because it feels like cheating when you can bend a LEGO piece to any shape using pliers. Still, there was no good alternative for it that I could think of this time.
