|Mining Truck (2016)|
Credit card and Paypal
Remote Controlled: Power Functions
With the release of the yellow rims of the Volvo wheel loader 42030 in 2014 it became quite obvious for me to design a Mining Truck to operate nicely together with my MOC Dragline Crawler Crane.
A quick sketch of the model I had in mind was: Remote controlled, working fake engine, full suspension and front/rear lights. At first hand, I thought that a model of this size would have place enough to add all PF equipment. However, it turned out this was not really the case. As one may noticed in real life, the dumpbed does not lay 'flat' on the chassis but at a significant angle. This has pros and cons. Pro is a tipping point not on the rear side of the dumpbed, allowing for less stress on the applied PF Linear Actuators for tipping; as the load in the dumpbed is before and after the tipping point. The con is that hardly not space is left between the front and rear wheels for PF equipment and dumping gears, which is even more challenging as the rear axle assembly joins the chassis with a 'ball-joint' setup that takes quite some space either. And, during the design it became obviously to use a 'twin' PF M-motor setup for dumping, each operating a PF Linear Actuator.
Another challenge was applying the PF XL-motor force to the rear wheels. Given the independent suspension, the PF XL-motor did not fit on the rear axle assembly. Moving the XL-motor to the chassis meant using a 3L 'universal joint' to apply the force towards the rear wheels. This was done by a triple stage of 12/20 tooth gear reductions, plus a double differential setup. The latter is done to reduce the stress on the fragile 12 tooth bevel gears used within the differentials. I had really doubts about the 3L universal joint being used in the drivetrain, but surprisingly it works really well and never led to damage; even not when driving outdoor.
The design of the front part of the model (V10 engine, PF lighting, steering) was a straight forward process, except for the suspension. I started with single springs at both sides, but notice during the build they were surpressed more and more until the front part of the model touched the ground. This was fixed easily by using double springs; although the chassis around the V10 engine area needed to be redesigned.
This time I really wanted the dumpbed to be completely closed to avoid tiny loads to be stuck in the dumpbed; this ruled out a Technic look-and-feel design. For the first time I used the MLcad program to design - in this case - the dumpbed, before building it in real life. This was done to have a clear view on avoiding any stacked bricks; which could be done faster in MLcad.
The Mining Truck has no reference to a specific Caterpillar® model; I used their white papers to understand how these vehicles operate and how they look-like in reality. As I did not want to apply decals for aesthetics the logo of Caterpillar® is made of stacked LEGO® plates.
The technic specifications of the 'Mining
* Remote Controlled
* Rear axle powered by PF XL-motor
* Double differential unit on rear axle
* Front axle steering by PF Servo-motor
* Full independent suspension on all wheels
* Working V10 engine with fan
* Dump bed tipping by twin M-motors, dump capacity 1 kg
* Working head & rear lights
Non-technic functions are:
* Cabin door open & close
* Cabin interior with seat and dashboard, and coffee machine
* Fuel tanks between the wheels
* Air conditioning units / filters / horn (on the battery box)
* Fire Extinguisher
* Gas bottles on the front grille zone
The dimensions of Mining Truck:
* Length: 37 cm
* Width: 24 cm
* Height: 21 cm
* Height with full raised dumpbed: 39 cm
* Weight: 2,7 kg
* Total number of parts: 2.127
Photo-shoot (The Netherlands):
* Construction 'bicycle bridge' A'dam Rijnkanaal, Nigtevecht
Of course, the Mining Truck can be loaded on my MOC Truck 8x4 with Lowloader.
Technical inside (cut-away render):
The Mining Truck is fun to play with! The driving speed has a moderate pace and does work flawlessly indoor as outdoor on solid surfaces. Steering works well either, however I have to admit that - due to lacking of Ackermann Steering - the Mining Truck reduces driving speed when sharp turns are made. Suspension is just doing what it is suspected to do; stiff enough to deal with a full load of cargo.
Tipping of the dump-bed is slowly to be able to dump at least 1kg of load. This could be sand - as shown in the pictures - but as well a full dumpbed of LEGO® Duplo bricks.
The front & rear lights do really add the finishing touch when driving in the dark; especially outdoor when the twilight kicks in.
As mentioned the rear axles are powered by a double differential setup; this works nicely and never led to any outages during the indoor or outdoor performances.
And real fun is to load the Mining Truck with the Dragline Crawler Crane.... although one can debate it the scale of both models do line up together ;-)
I like to highlight 3 parts that proofed to be very valuable in the design of the Mining Truck.
Technic Universal joint 3L:
Magnificent to see that this part is strong enough to apply the XL-motor force to the rear axles without breaking into pieces; of course this is partly related to the many down-gearings in the drivetrain.
Technic Pin with perpendicular pin-hole:
Althought just release in 2014, I really learned how useful this part is. The Mining Truck has 23 of them.
Tile 2 x 4:
What can I say? I just used 54 of them :-)