[TC21] Quadcopter-Car

[BrickBuildingFox]

I think this contest is very difficult from a mechanical perspective... but anyway challenge accepted

My plan is to build a car, that transforms into a quadcopter:

Outline:

• Control+
• 4 wheel drive
• articulated steering
• low gear in car-mode and high gear in quadcopter mode
• some kind of chassis transformation
• optional: 2-stage transformation: lift car to quadcopter stand, then turn the wheels into propeller-mode

Concept for axle:

 

[MY1]

to have the wheels double as the rotors would probably be really weird-looking. I think having rotors that are hidden during car mode and come out might have a better appearance 

Edited November 23, 2021 by MY1

[Gray Gear]

I agree I doubt it would look much like a quadrocopter with the wheels up...

Maybe try to use larger wheels that are not as wide, like motorcycle wheels! They could look okay as rotors I think.

Edited November 23, 2021 by Gray Gear

[whitepen]

2 hours ago, MY1 said:

to have the wheels double as the rotors would probably be really weird-looking. I think having rotors that are hidden during car mode and come out might have a better appearance 

Yeah, this sounds like a good idea, but it would be harder to hide massave rotor blades in a car.

[Jurss]

10 hours ago, whitepen said:

but it would be harder to hide massave rotor blades in a car.

That is why we have contest

[BrickBuildingFox]

On 11/23/2021 at 6:06 PM, MY1 said:

to have the wheels double as the rotors would probably be really weird-looking. I think having rotors that are hidden during car mode and come out might have a better appearance 

I agree, that it looks weird... originally I wanted to build it like this because of simplicity.

On 11/23/2021 at 8:42 PM, whitepen said:

Yeah, this sounds like a good idea, but it would be harder to hide massave rotor blades in a car. 

Indeed this would be harder and I never designed some complicated lever mechanism... but lets try:

I know this looks ugly but I just want to build some concept how it may be able to work:

It is really difficult to find the right ratio of wheel and rotor size such that the vehicle will have reasonable proportions....

It will be even more difficult to connect the rotors to a motor

This is really a tough contest! I will keep trying...

[Jundis]

40 minutes ago, BrickBuildingFox said:

It is really difficult to find the right ratio of wheel and rotor size such that the vehicle will have reasonable proportions....

It will be even more difficult to connect the rotors to a motor

This is really a tough contest! I will keep trying...

But it looks so much cooler now ;-)

Maybe with chain-drive?

[MY1]

the mechanism that you showed in the gif looks really cool. In terms of driving both the wheels and rotors, you could have an orange rotary catch linked in a 2:1 ratio to the axle, used to switch between modes. The orange rotary catch would be attached to a gearbox that switches the drive from the rotor to the wheels. I've noticed that on mini LAs if you  turn the orange axle the extending part will spin freely. using this idea you can have an extendable drive axle that could connect to the rotors using a series of U joints 

[BrickBuildingFox]

On 11/27/2021 at 4:03 PM, Jundis said:

But it looks so much cooler now ;-)

Thanks :)

On 11/29/2021 at 4:19 PM, MY1 said:

the mechanism that you showed in the gif looks really cool. In terms of driving both the wheels and rotors, you could have an orange rotary catch linked in a 2:1 ratio to the axle, used to switch between modes. The orange rotary catch would be attached to a gearbox that switches the drive from the rotor to the wheels. I've noticed that on mini LAs if you  turn the orange axle the extending part will spin freely. using this idea you can have an extendable drive axle that could connect to the rotors using a series of U joints 

Good Idea, I will keep it in mind

 

So, now I build the next prototype, which works quite well. However, I still need to add the Wheel...

 

On 11/27/2021 at 4:03 PM, Jundis said:

Maybe with chain-drive?

Do you suggest to build a Tracked-Quadrocopter or use the chain to drive the rotor (as I used for this prototype)?

[BrickBuildingFox]

Finally I have a prototype of the full axle in front. I will build a similar one for the back.

I only need to do some minor improvements to increase the statics of the frame and reduce friction in the drive train.

However, the friction of the rubber tires make it very inconvenient to turn them 90° (as shown in my previous GIF above).

I will build some kind of scissors lift to lift the car in the beginning, and then extend the rotors.

To follow the rules of the contest (1 motor for transformation) I designed this 2-stage gearbox:

Wish you happy holidays!

[Jundis]

Whoa, this is coming together nicely! I hope the 2 stage concept works. The speed of the rotor is great :-)

Would this rotor also fit with an 3 stud axle + stud at the end?

https://www.bricklink.com/v2/catalog/catalogitem.page?P=15790&name=Propeller 3 Blade 9 Diameter with Center Recessed&category=[Propeller]#T=C

[BrickBuildingFox]

On 12/25/2021 at 10:02 AM, Jundis said:

Whoa, this is coming together nicely! I hope the 2 stage concept works. The speed of the rotor is great :-)

Would this rotor also fit with an 3 stud axle + stud at the end?

https://www.bricklink.com/v2/catalog/catalogitem.page?P=15790&name=Propeller 3 Blade 9 Diameter with Center Recessed&category=[Propeller]#T=C

Yes, it could work (max size is 10 studs diameter) and that one has 9... however I don't own them and also I am not a big fan of these Propellers, because they don't have axle hole :(

Currently I am working to finish the central gearbox with motors... its quite tough to fit everything

[BrickBuildingFox]

Finally some progress...

I finished the central gearbox and the transformation is basically working:

Car mode:

The first step is to lift the car:

then extend the rotors

 

I still have two major problems:

- the ground clearance is technically 1/2 stud, but basically 0 because of the weight of the central gearbox

- the gearing ratio for the steering need to be adjusted and improved to make sure the gears are not "jumping"

And the chassis need to be designed as well...

I am happy the contest is prolonged. I guess these problems can be addressed until end of January.