Motorized Liftgate Truck
LEGO Ideas project: a simple truck with motorized liftgate, a working pallet jack and pallets with cargo.
Datasheet:
Completion date: 30/09/2023
Power: electric (Control+)
Remote control: none
Dimensions: length 40 studs / width 15 studs / height 25 studs
Weight: 1.522 kg (including accessories)
Suspension: none
Propulsion: none
Motors: 2 x C+ M
This LEGO Ideas project can be supported here: https://ideas.lego.com/projects/3206ab8f-b660-444b-8052-8563021fb622
A simple truck that I developed in an attempt to bring some Technic into LEGO Ideas. It was inspired by various delivery trucks I keep seeing around the town, which often sport custom-built cargo boxes with somewhat cartoonish proportions. My focus was on playability, so the truck is manually driven and steered but the two liftgate functions: tilt and elevation, are motorized using “dumb” Control+ hub with two levers. This means that the truck requires no app and no smartphone, because the motorized functions are lever-operated. I’ve had opportunity to operate a liftgate on a real truck and found it quite interesting, but at the same time I haven’t seen a single Technic set featuring such a function.
The truck sported steering controlled by a knob on the cabin’s roof, coupled with a working steering wheel inside the cabin. The cabin doors could be opened and the liftgate could be tilted and lifted with motors. For extra playability, I have added a simple pallet jack with working steering and lifting mechanisms, along with three pallets, two of them with appliances on them. Additionally, a section of the cargo box’s roof could be removed to access the batteries in the Technic hub.
The entire project was a balancing act. I was trying to approach it like a LEGO set on a budget, so it was size VS functionality, looks VS playability and so on. The looks were quire obviously secondary to functions. Basically, my goal was to build a Technic set of a kind I’d like to play with, and I don’t like having to use a smartphone as well as having to rotate linear actuators manually, which takes ages. I’ve tried to keep it in the “pure Technic” spirit.
The primary challenge was fitting the dumb hub with two motors and two complex linkages beneath the cargo box. The result is that the cargo box is sitting quite far off the ground, but I thought that this may actually be an advantage, because what’s the point of building a complex liftgate if you only lift things a little? Another challenge is that I was trying to make the motorized functions safe to play, meaning that the ends of the liftgate’s range of motion would converge with ends of the linear actuators’ range of motion. It was demanding to design, but the result was that e.g. when the lift reached topmost position, you could keep the motor running and it would simply make the clutches in the linear actuators slip instead of trying to jam the liftgate into the cargo box. Finally, I was trying to keep the liftgate itself as flat as possible. I have managed all that, but at the cost of some imperfect geometry – namely, when the liftgate reaches its topmost position, it’s still a bit lower than the floor of the cargo box.
The truck was a nice challenge and presented me with some unusual factors to balance against each other, and it ended up being very playable.
