Crane Truck 42009c (2015)


Building instructions (PDF)
(447 pages)
Example instructions (PDF)
Parts Inventory:
(2.290 parts)

Credit card and Paypal



Manual Controlled

As a challenge, I designed an alternative (or C-model) of the original LEGO® Technic set 42009 (Mobile Crane MKII). Given the number of wheels in this set, it was quite obvious to design a truck whereof I could use all the 10 wheels. A logicial wheel setup is used whereof the 2 front axles can steer, the 1st rear axle has a twin-wheel set-up and the 2nd rear axle can steer as well. To make effective use of the linear actuators and gear racks in the original set I came up with the idea to have outriggers and a crane as additional functionality. Putting these thoughts together I started first with the design of the crane including a clamp; based on my roll-loader crane (MOC Stone Trailer Truck). Next step was to design the front part of the truck with the cabine as I liked them to have an appealing look without part/color limitations except for the parts/color available in the original set. Having succeeded that, I moved on to the outriggers and the loading bed of the truck. Finally the chassis sides (mudguards and striping) and the rear chassis were designed. The 3 pallets with it's cargo were build with the left over parts. The result is the Crane Truck 42009c.

Challenges in designing this time was the limitation in parts and the available colors of these parts. And, I really wanted to use all wheels, the linear actuators, gear racks and panels; this is the case except for just 1 mini linear actuator. Regarding the chassis sides and loading bed: they needed a couple of iterations before it worked out the way I liked it. The fun part is that the pallets can slide for/backwards on the loading bed quite easily without falling off.

Regarding the power functions (L-motor): I left it out as I wanted this model to be manually operated as I (and my kids) are always mixing up the battery switch direction in relation to the movement of the Technic functions.

For those remembering the LEGO® Technic 8258 truck: this C-model has similarities in appearance but is completely designed in a different way.













The technic specifications of the 'Crane Truck 42009c' are:
* 4 axle truck with working V8 engine
* differential unit on the 3rd twin-wheel axle
* Steering on the 1st, 2nd and 4th axle
* Cabin tilting, driven by 2 power functions mini linear actuators
* Outrigger extension at both sides between the 1st and 2nd axle
* Crane: 1st & 2nd boom lifted by power functions linear actuators
* Crane: 2nd boom extension ~ 7 studs, crank operated slew of 360°
* Clamp can be opened/closed to lift pallets

Non-technic functions are:
* Cabin doors open & close
* Swing down panels to access outrigger operation mechanism
* Raise-able wind deflector
* Pallets stackable on each other




Details applied:
* Cabin interior with 3 seats and dashboard
* Fuel tanks, air compressors and air filter units between the wheels
* Air compressors between rear wheels
* Air conditioning units, flashlights, exhaust pipes, cabin roof horns
* Cargo load (‘gear-spindles’)

The dimensions of Crane Truck 42009c:
* Length: 57 cm
* Width: 16 cm
* Height: 24 cm
* Height with full raised crane: 49 cm
* Weight: 2,1 kg

* Total number of parts: 2.290

Photo-shoot (The Netherlands):
* Reconstruction high-way A1, nearby Weesp


Technical inside (cut-away render):


The model is designed with play-ability in mind. Driving and turning curves works out smoothly whereof the steering operation is done from the backside (same as the 42009 Mobile Crane MKII). The cabin tilt function will be done by turning the little black gear in the grille of the truck's front side. By swinging down the yellow panels between the front and rear wheels it is possible to access the outrigger mechanism. Just turn the gray gear to extend or extract the outrigger of that side. To stabilize the outrigger the gray gear on the outrigger must be turned.












Operating the crane is done by 3 cranks. Two are used to raise/lower the 1st or the 2nd boom section. The third one is used to slew the crane, whereof the slew has no limitations. It can rotate the full 360 degrees and even drop pallets in front of the cabin!
The 2nd boom section can be extended by operating the gray gear on it. The clamp can be opened or closed by turning the gray gear on top of the clamp that drives a mini linear actuator.

Fun part of the crane is that it can picks up 2 stacked pallets together (see left photo). And, stacked pallets are really stacked: no sliding possible. Other fun part is the ability to slide pallets backwards of forwards on the loading deck without having the pallets slide sideward at the same time!













Original 42009 set, parts not used:
Not all 2.606 parts of the original set 42009 are used within the Crane Truck 42009c. On the picture you can see all the parts not used; the number of 'left-over'  parts is 316. That is quite reasonible in my opinion as a significant quantity of them are axles and pins.