RC Quad-Motor Rally Car Chassis

[z3_2drive]

Hello! I'm back with another MOC, most likely the last one for a long time as I'm rapidly approaching a Lego dark-age of my own (college). This time around I'm finishing off my series of high-speed vehicles with a special rally-style chassis. It is my best handling version so far and it actually has bodywork (more of a tubular rollcage). Details:

• RC - featuring the custom electronics I've been using for previous versions. Link for those who haven't seen my setup yet.
  
• 4 Buggy motors for drive (2 driving each rear wheel, disconnected in the middle).
  
• Servo steering (normal Lego servo).
  
• 4 Wheel independent suspension - rear includes anti-roll bar and shorter top links while the front has caster and active camber due to shorter top link. Both axles have modified pneumatic cylinders acting as springs+dampers together.
  
• Extremely sturdy chassis with little to no twist (I tried hard to twist it from end to end, doesn't budge) plus sturdy rollcage that can be used to pick up the MOC.
  
• 3D printed wheels by efferman, as well as 3D printed spherical gear counterparts that act as really strong CV joints.
  

The sturdy construction allows the suspension to work as intended, absorbing every bump. Here is the video:

And now for a photo dump:

Hope you guys like it! Sorry purists

Edited April 28, 2016 by z3_2drive

[JJ2]

Your very best yet! I really like the suspension and the anti-roll bar, how much did it improve handling?

[2LegoOrNot2Lego...]

This one is darn fast, cool!!! Like the way you used the parts, including the none LEGO parts... Well done...!

[BusterHaus]

Holy cow that's got some fantastic performance. The pneumatic dampeners really make all the difference by not bouncing up and down. How did you seal them? Also, how do the Bionicle joints in the front hold up over time?

[z3_2drive]

Thanks guys! Anti-roll bar helps slightly in the back since the rear is a bit heavier, but they are not as stiff as I'd like.

Holy cow that's got some fantastic performance. The pneumatic dampeners really make all the difference by not bouncing up and down. How did you seal them? Also, how do the Bionicle joints in the front hold up over time?

Pneumatic cylinders come with rubber parts inside that help seal air, simply remove one to get a spring inside and put it back on. Bionicle parts hold up fine, I can lubricate them for less friction in the steering but I'm running them dry and they still work good. Edited April 28, 2016 by z3_2drive

[AndyCW]

What are your thoughts on the wheels?

I trying something similar, but working on 4WD.

I like the sway bars.

Good luck with school, we'll be here when you get back.

v/r

Andy

[z3_2drive]

What are your thoughts on the wheels?

I trying something similar, but working on 4WD.

I like the sway bars.

Good luck with school, we'll be here when you get back.

v/r

Andy

Thank you! The wheels are fine, the more recently printed pair seem to be higher quality and didn't require any sanding of the pin holes, but you might want to loosen the axle hole a bit. Overall I'm pleased, but with my wheel hub setup which is particularly wide on the bottom (front axle) the wheels rub slightly and this results in a good amount of friction. I might change something to prevent this, but that's on me. They also have a nice offset, which always helps handling.

Edited April 28, 2016 by z3_2drive

[efferman]

How is the stabilitiy of the superleggera rims?

[Didumos69]

As you probably already know, I like the combination of a sturdy chassis and properly operating suspension. Also nice to see the caster angle, active camber and the anti-roll bar. My compliments!

Looks like you've been watching nicjasno's video's ;-)

Edited April 28, 2016 by Didumos69

[TheNextLegoDesinger]

I really love it, it's one of the best i've seen so far

[SevenStuds]

Very cool chassis you have here with many unique features! Great performance too with all those motors!

[Oliver 79]

Very clever use of parts. That suspension set up is pretty nifty. Well done!

[AndyCW]

After looking at it again, I'm getting a

vibe.

v/r

Andy

[timslegos]

Great looking car, and the functionality is certainly there. The caster seems a bit extreme though.

[z3_2drive]

Thanks for the positive feedback everyone!

@effe the wheels seem very stable, slightly more flexible than a Lego ABS wheel, which might be a factor in the rubbing issue, but I really like the wheels and can't see any issues.

@Didumos yup, his ideas directly influence the design, and he's helped me with fixing suspension issues on previous versions. Not to mention his custom hubs are a necessity for any heavy, high speed vehicle.

@Andy slightly less wheelspin

@tim yeah, the angle might contribute to the rubbing of the wheel, I might reduce the angle if it becomes a problem.

[piterx]

that's sick man! awesome job

[Victor Imaginator]

Impressive crazy performance)

[Lox Lego]

Very interesting build. I'm jealous it performs so well!

I'd love to see a super car built out of this chassis...

[z3_2drive]

Thanks guys!

@Lox maybe one day...

[__________________________]

I think it would be incredible with a real body, maybe you could pair with a builder who is established in this area.

Excellent performance imo