Robby Gordon's Dakar Hummer 2012.

flickr http://www.flickr.com/photos/marat_andreev/sets/72157636448582035/
video http://www.flickr.com/photos/marat_andreev/10217855464/in/set-72157636448582035


Robby Gordon is American racing driver. Over the years he participated in many kinds of racing.
I modeled Dakar Hummer H3, driven by him and his co-driver Johnny Campbell during 2012 Dakar Rally Raid in South America.
The model features: rear wheel drive via 2 L-motors, steering via servo-motor, front and rear independent suspension, open-able hatch with 2 spare wheels, detailed livery and custom painted rims.

1)2 L-motors drive left and right wheels independently, eliminating need for differential and acting like a limited slip differential at the same time. Motors are geared up using 20/12 bevel gears. When designing I included additional pair of 16 gears into drive lines. If  the completed model had been too heavy or too light, I would be able to change gear ratio without redesigning driveline.
In the end 5:3 total ratio turnout to be optimal.
2)Rear suspension is authentic trailing arm suspension with big shocks absorbers. I used a multilink front suspension instead of more accurate double A-arms. The idea is to make wheel pivot point closer to center of wheel, which also allow me build narrower fenders. This is design similar to my IDOT tow truck steering. It was originally inspired by LPEpower videos.
3) The livery is recreated using both sticky and water-slide decals. Main advantage of water-slide decals to me is the transparency. I do not have to worry that orange color is different between bricks and decals. Minor disadvantage of water-slide decals is white color. While it is possible to print water slide decals with white color, I used a regular laser printer without such capability. Thus I used sticky paper for decals with white color. 

4) Rims were painted by my friend Pavel with airbrush using Testors gloss tangerine paint. 

In many ways this model is successor to my Dakar Kamaz Rally Truck. The idea was to build something smaller, more powerful and a little more challenging visually. I am happy with the result. The Hummer weights only 1.2kg (Kamaz is 1.7kg), has almost twice the power, and looks good =)

I would like to thank my friend Pavel, Brickmania for their water-slide decals workshop on Brickworld 2013 and LPEpower for their amazing videos about LEGO cars. Also thanks to all Hummer/HUMMVEE lego builders for inspiration.

WIP annotiation
This is wireframe I used to pick a scale. Also it is very useful for testing internal layout of components.
This is internal chassis of the Hummer. The picture is taken during late WIP stage. Only difference from final design is use of "soft shock absorber 9.5L" in the rear suspension. The completed model was to heavy for them. Final design uses rare "hard shock absorber 9.5L".