Mini AWD Trophy Truck

[Zerobricks]

This is a small AWD Trophy truck that I was able to build thanks to the new components in the Skyline, specifically the 4L links and the 4L CVs:

The biggest challenge with this model was in finding a solution for the FWD which would allow for high suspension travel and a good steering angle while being limited to 25 degrees of movement of the CV joints.

I decided to bring the front suspension arms closer together, therebye creating the following suspension geometry which forces the front wheels to move in an arc:

This in turn has several advantages:

1. Reduces the angle the CV joint has to carry the power on the outboard side
2. Allows for a higher steering angle
3. Increaces the ground clearance on the bottom

As such the front suspension is supported by 2 soft shock absorbers. Notice how the L liftarms hold the suspension together, supported by a white bar that goes through the cross hole:

The rear suspension uses the normal equal length parallel arm design and it's supported by a combination of a hard and soft shock absorber which are placed at an angle to simulate a progressive setup:

 

The front axle also uses double steering rack simillar to 42160 with 4 steering links to keep the front steering system as accurate, robust and stiff as possible (Please note, there are no 4L link yet available in LDD):

Originally the driveline used a 12:20 gearing from the motor to the main shaft and than the 20:28 to the wheels.

I used a couple of bevel 20 tooth gears so that a 5x11 panel could fit under them to protect the gears.

But during video shoot, the solution proved to be a weak point, so I redesigned the driveline to use a pair of 16 tooth gears and a 12:28 diff combo which gives me the same gear ratio, yet with added strength:

The only weakpoint left were the small CV recepticles:

But after reducing the current limtiters from 2 to 1.5 A, I have yet to suffer a failure, even when suddenly changing directions.

 

You can see the model in action here:

I have to say this is a really compact, fun and almost indestructible model and I'm really happy how it turned out. Now if only LEGO could come up with a 4L version of the large CV joints...

Edited 9 hours ago by Zerobricks

[1gor]

I saw YouTube video today and must admit that it is very cool little trophy truck. Years ago I was thinking about something like that to implement my buggy motor but there were no short enough suspension arms available...yes, we defenefelly need stronger CV joint with less slack one stude wide; new stronger CV joints are sometimes to big and don't fit 1 stud wide space...

 

Edited 5 hours ago by 1gor