The product of a failed attempt at a MINI Coupe, this small car features full R/C capabilities, full suspension, and a 4-speed dual-clutch sequential transmission.
About this creation
Propulsion: 1 x RC Buggy motor, from fast output Steering: Front wheel with 1 x Servo motor Drive Type: RWD Transmission: 4-speed dual-clutch sequential with 1 x M motor and ďrace-styleĒ gear ratios Weight: 0.87 kg (1.92 lbs, ~249 LEGO minifigs) Length: 30 cm (11.8 in, 37.5 studs) Width: 14.5 cm (5.7 in, 18 studs) Height: 9 cm (3.5 in, 11 studs) Power source: 8878 Li-Po Rechargeable battery box Estimated part count: 600 pieces Suspension:
--------Front: dual-wishbone independent
---------Rear: dragged axle Build time: ~57 days
The product of a failed attempt at a MINI Coupe, this small car still sports all the features of a normal supercar. It is fully motorized, with drive, steering, and a 4-speed dual-clutch transmission all controlled remotely.
WellllÖ this is where things get a bit awkward. I was originally trying to make a MINI Coupe, but the ground clearance ended up 1 stud too little; and with no way to change that short of destroying a perfectly-good chassis, I elected to come up with my own car. Ladies and gentlemen, I present to you the Ira Anao.
The drivetrain and the overall functionality of it was most of the reason I was reluctant to tear this thing apart and start anew. An RC Buggy motor supplies the drive through the fast (outer) output, which is then routed through a 4-speed dual-clutch sequential transmission at a 1.67:1 ratio. After that, the drive is put through a universal-joint into the dragged-axle rear differential.
The transmission is almost identical to my previous version, except the ratios have been changed from:
5:1, 3:1, 1.67:1, 1:1
2.08:1, 1.67:1, 1.25:1, 1:1
This idea in doing this was that the closer ratios would allow the car to accelerate into a speed than I would add otherwise. It actually worked pretty well, and I could change gears up and down almost like it was a real car.
Steering was an easy system but an interesting one. Itís detailed in the above photo, but to truly understand how it works, you should take a look at the video at the top of the page. Go ahead, I can wait.
Back already? Okay. The steering itself was controlled by a servo motor because of the fast response time and easy control. There was a little slack in the steering system but in the end it did the job.
Suspension and Chassis
Suspension couldnít have been much easier. The forward suspension was just a simple dual-wishbone using the parts from the 9392 Quad Bike and a single hard 6.5L spring for the elasticity. Rear suspension was a dragged axle Ė which I normally donít like to use, but tiny cars call for desperate measures.
The chassis was built in a unibody format with double frame rails, and the result was very rigid and relatively lightweight structure. Something to be used again in the futureÖ
Because there was no subject vehicle, I was pretty much allowed free rein in designing the body. I suppose it looks pretty good overall, although something about the side profile looks a little off to me. Iím happy to hear comments on any aspect of it.
Iím actually quite happy with this car. It looked decent Ė considering I designed the body Ė and I think I did a pretty good job with the functionality considering the space; despite the size, the car was still more functional than, say, a certain $300 2700 piece behemoth.
Next time, Iíll try to keep ground clearance in mind.