A studless version of the garbage truck with skid steer remote control and a V8 fibre optic engine.
About this creation
After building the 8868 airtech claw rig, I began to think about the alternate model, a garbage truck with a very clever yet simple automatic pneumatic circuit controlling the arms and front grab jaw.
Sadly this model did not have an engine or any drive to the wheels, so I thought it was time to give this vehicle the features it deserved!
I decided straight away the vehicle should be completely studless in design and should feature the new lego power motors, like the one in the bulldozer (8275) So after ordering the motors and other bits from lego.com, I got to work.
I had always wanted to build a skid-steer drive with an engine, and thought that the engine should be driven by its own seperate motor, rather than the motors driving the model itself.
Here is the basic chassis, where you can see the 2 drive motors and gears. The gray bent liftarms with pins came in very useful here and gear reduction is supplied by the large 40 tooth gears. Note the strong bracing around the bevel gears.
When modeling the arms and front grab jaw, I closely followed the original design to get the look and size just right. The front grab jaw gear mechanism took some trial and error to develop.
The "central plexus" I had to experiment a lot to get the central switch just right on the pneumatic valve, and it took a while to place the single piston operating the second valve. The roof has been adapted to hold the IR remote where there would normally be a "hand of god" steering wheel; not needed in a skid-steer drive. I have modeled the battery box (not shown here) and fuel tank as close as possible to the original.
I decided on yellow for a color scheme when modeling the rear canopy area, the IR reciever is located high to receive the signal.
The classic dual opposed pump compressor is simply a studless version of the one used in the airtech claw rig and was the first part I developed.
V8 fibre optic power! I had always wanted to build this engine, and one day sat down to develop it. As there are 8 fibre optic cables, a V8 was the natural way to go. I thought this would be simple, but as usual with lego technic, it wasn't! After many weeks I hit upon this design which gives the look of ignition wires I was after and the speed I wanted; with the 24 tooth driving an 8 tooth gear, the engine and FOS spin 3x faster than the motor.
Finally after many months and $$$'s spent this model is finished! I am trying to get yellow parts instead of white for the fuel tank. I think now my obsession with 8868 has finished!