Video Presentation

Specifications

• Model inspiration : Western Star and International Truck models
• Dimensions : 24cm (52.5cm with trailer) x 8.5cm x 11cm Øwheel : 37mm
• Three versions available : Manual, Power Functions or Control+
• Rear wheel drive with a L-motor and differential
• Small turning radius steering with PFS Servo motor or Control+ L motor, rack and pinion
• Battery source : PFS+Buwizz 2.0 or PFS+2.4GHz battery or C+ and C+hub or C+ and Buwizz 3.0
• On manual version, the steering operated by Hand of God on the top of the cab
• All versions are included in a single package and are upgradable from and to each version
• Middle axle with trailing arm suspension to avoid losing traction on uneven ground
• Tri-Axle Trailer with fixed or automatic steering axle using linkage and a locking pin
• Landing gear on the trailer with friction gears
• Openable doors and hood (no fake engine)

How to build ?

📕 You only need the parts and the instructions. You can purchase the PDF instructions on this shop (all versions included) and build with your own parts (you can build the manual version, then upgraded later by adding the motors and battery/remote). The Rebrickable inventory included the parts to build all versions so with spare for the manual one). See the end preview below to see the difference.

🎁 If you want to purchase the LEGO parts + PDF instructions, have a look to my creator page or request a quote from :

• Using Genuine LEGO Parts : Buildamoc
• Using non-Genuine LEGO Parts : LesDiy Store

⚡ For motorized version : In addition of the motor (PFS or C+), the model can have different remote controlled solution :

• In Power Functions System : 1x BuWizz 2.0 and a compatible smartphone (PDF tutorial included), or a generic PFS 2.4ghz Battery Emitter and Receiver (Cada, Mouldking or other Chinese brand) or legacy PFS infrared system (8881+58123a+8885)
• In Control+ system : 1x Control+ Hub (ref 22127 or 85824) (PDF tutorial included) or 1x Buwizz 3.0 with compatible smartphone (PDF tutorial not included, on request)

👍 Thanks to TechnicMOCer for his axle trailer system who inspire me to make my own version which is basically an improvement over his one.

About this product

Instructions preview

Design Process

This model was created for a Truck Exhibition in France to show the possibility of LEGO Trucks in a functional and fun way, either manual or motorized.

So I started designing the truck to be the smallest possible with the two motors, that is why I chose the 37mm tire to fit all electronics needed. Plus they have the perfect tire ratio for Heavy Duty Truck looking.

Because of the tight space, only the rear axle is powered, and the rack and pinion of the steering is placed in front of the front wheels. Speaking of the steering, I wanted to maximize the turning abilities so I design in a way the range of motion is maximal without colliding with anything, which contributes a lot to the playability.

After a few tests, I noticed that the truck could get stuck on small bumps because the central axle was lifted and the rear wheels lost contact with the ground. So I added a rudimentary suspension system in the form of a trailing arms on the central axle, which absorbs bumps that could otherwise cause the rear wheels to lose traction. 

On the Trailer, I wanted to experiment with steering axle trailer for a while so I was inspired by the Mini Scania R420 and Steering Trailer by TechniMocer which I reused the functioning principle : a lever connected to the saddle operate the trailer axles.

Nevertheless, I have improved it with a smaller height for the mechanism, enabling to have the trailer near the rear wheels without any collision. Plus increasing the range of motion of the steering primarily due to extended width. The Truck / Trailer articulation can achieve ±75°.

An other functional addition is the locking pin mechanism which enables to choose between two mode of steering for the trailer : fixed or steerable. Simple but effective, as it can be difficult to drive backward the trailer with steering axle mode.

For the details, there are quite standard with interior, seats, lights, mirrors and exhausts. The doors can be opened as well as the hood but reveal nothing (no fake engine). The most difficult parts was to reproduce the original form of the cab in a clean look with has many variation in width. For instance the chassis is in 9/11 stud wide, while the cab is only 8 stud, the grill 6 and the mudguard 10, so as you assume there is a lot of half-stud offset inside.

I added a minifig inside because I find it funny, even if it is a bit small for the truck (1/43 instead of 1/30). The Rebrickable model do not include it, but the cookie and mug is here !