AWD 42109 TG Rally Car

[N1K0L4]

Hello, 

so after the Mini AWD 42109 TG Rally Car I was thinking of making a full size one and finally putting that body on AWD chassis. My goal was also making the drivetrain efficient and powerful. This is the result.

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Most of the body was kept as original, but has quite some differences as well.

For the drivetrain I got inspiration from @Zerobricks  Mustang GTEX AWD. So each motor drives it's own rear wheel (20:16 from slow output, plenty fast and still has enough torque) which than power a differential. That differential averages the rpm and sends that average to the front wheels via another differential. In the front I used gears instead of CV joints to be able to have much higher steering angles (25°-30°). When you first see that approach you might think that the gears will just skip under power, but no. They are being pushed together by the weight of the car and can not skip.

Model is powered by BuWizz 3.0 Pro and 2 BuWizz motors and steered by a PU L motor. I could've gone for a layout that allows for interior and other scale details, but the reason I've gone for this is that I can have as much weight in the center and on the front wheels. Because of that the car is surprisingly agile even though AWD cars naturally produce understeer. One thing that also helps with agility is torque vectoring / skid steering on the rear wheels. I have the coefficient set to 0.12. Also I kept the front differential unlocked which makes it much easier to rotate at low speeds.

Main goal of this model was of course to make a model that can drift with ease and lets me enjoy it. I'd say I managed to do that pretty well. With the help of some 3D printed tire covers (tape works too, but not as well) it slides like a dream.

 

Video showcasing the model:

Instructions: https://rebrickable.com/mocs/MOC-218801/N1K0L4/awd-42109-tg-rally-car/

Tire covers: https://www.printables.com/model/1292404-drift-cover-for-lego-432-x-20-mm-tire

BuWizz components: https://buwizz.com/

 

Overall, I'm really happy how this turned out, hope you like it too :)

Nikola

[Zerobricks]

Well done, glad to help inspire you! I see it drifts really nice and seems to be easy to control. Only question/commend for improvement would be, why not use the clucth becel version of the 20 tooth gear to reduce friction?

[Aurorasaurus]

12 minutes ago, Zerobricks said:

Well done, glad to help inspire you! I see it drifts really nice and seems to be easy to control. Only question/commend for improvement would be, why not use the clucth becel version of the 20 tooth gear to reduce friction?

I think it doesn't fit because of the extra half stud of the pin hole, which collides with some of the bracing parts for the axle that holds the wheel.

[N1K0L4]

5 hours ago, Zerobricks said:

Well done, glad to help inspire you! I see it drifts really nice and seems to be easy to control. Only question/commend for improvement would be, why not use the clucth becel version of the 20 tooth gear to reduce friction?

Thanks, your models are always good inspiration ;)

4 hours ago, Aurorasaurus said:

I think it doesn't fit because of the extra half stud of the pin hole, which collides with some of the bracing parts for the axle that holds the wheel.

Yes exactly that.