John Deere 8RX Tractor - 42168 alternate build with tracks

[Timorzelorzworz]

Hello Community,

I want to share a cool idea and model I came up with - using relative new 28T gears as sprockets for a tracked vehicle.

When I first saw the inventory for the new 42168 John Deere 9700 Forage Harvester, I was impressed on how many gears are packed inside this small model so I decided to use as much as possible of them for a tracked Tractor. 

But can all that gears are used as sprockets for driving small tracks? Lets find it out.

The new 28T gear fits literally perfect as sprocket and thanks to the soft tooths of that bevel gear, tracks are running surprisingly smooth. Every second tooth fits inside the gaps of the track links, where the other tooths fits inside the gaps of the track part itself and so on.

With such a setup it might be possible to build a tracked vehicle and I tested alot on the tracks and the sprocket setup. Available gears from the 42168 Forage Harvester are not enough, so I decided to use the yellow gears only for the visible side of the model and to use other parts provided with the set to prevent the additional tracks from slipping...

The model I ended up is a John Deere 8RX Tractor as alternate build for the 42168 John Deere Forage Harvester that requires 124 additional widely used track links (part 3873). 

Something odd, a model that requires additional tracks and let you the tires left over for some other cool stuff. The Tractor comes with steering and a working piston engine. Only parts from donor set 42168 are needed and all functions are working even without the additional track pieces.

Lets take a look how smooth the tracks are running.

 

The model is steered with wheel from the back (shown in blue) while the rear tracks are running the piston engine (shown in green) by driving the model smoothly over rough ground.

Let the piston engine run by driving the tracks or by rotating the rear sprocket manually.

Some impressions:

 

If you like what you see and want to build your own John Deere 8RX Tractor Unit, feel free to support me on rebrickable.

Happy Building.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Lego Tom]

Huh, well that's pretty darn cool!

[Maaboo the Witch]

Cool. Very reminiscent of the 42121 B-model!

[Jundis]

Such a cool model and great find with the 28t gears driving the tracks!

[Timorzelorzworz]

6 minutes ago, Jundis said:

Such a cool model and great find with the 28t gears driving the tracks!

Thanks, never thought before that it can work but it does surprisingly good

[Thirdwigg]

Great job @Timorzelorzworz you managed to get the tractor proportions just right on this build, and good idea using the gears for the tracks. Another build you can be proud of.

[deraven]

Interesting to learn how well those gears work with the tracks.  Thanks for investigating, illustrating, and demonstrating in that great mod, too!  

[eric trax]

Fantastic mini tractor. I really like how you design the tracks. Good job! 

[Timorzelorzworz]

15 hours ago, eric trax said:

Fantastic mini tractor. I really like how you design the tracks. Good job! 

Thanks alot, appreciate that much from an tractor expert