[MOC] CityAirbus Air Taxi

[Brickthus]

Following my disappointment that the Osprey 42113 did not follow the normal pattern of availability and cost, I decided to build a civil aircraft MOC of a similar price point.

I chose the CityAirbus because it has an interesting configuration, not seen before in LEGO Technic.  The real one is all-electric, improving on the usual gas-guzzling Technic prototypes.

There was also room to innovate in the model.  A lot of prototype aircraft inherit a shell from an existing one and fit new equipment, which doesn't make for such an interesting model.
With Technic we want to see the new mechanisms, so I left the underside open to view the gearbox.

There are three motorised functions: rotor spin, a "hovering" mechanism and a movement mechanism.
A single L-motor powers the 8 rotors and a selection gearbox for the other 2 functions.
The right lever does the hovering mechanism, which lowers a pair of linear actuators that move clear beams to raise the aircraft off the ground.
The left lever does the movement mechanism that powers a sliding axle arrangement that drives clear wheels on the feet of the scissor jack.

The two manual "mechanisms" are removal of panels on each side and the ability to rolls sideways when landed, using small wheels on the skids.

The red lever sows the centre of the function selection gearbox.  It works like the one on the back of Claas tractor 42054.
The rotor drive comes from the centre of the gearbox, using the reversing bevels, and goes up, then diagonally to reach the front rotors.  The rear rotor drive goes along the top.
My first prototype test model allowed the rotors to tilt in sided pairs but they do not do so in the real CityAirbus.
The motor is above and to the rear of the function gearbox.
The hovering mechanism is geared down by worm but has a small gear-up before the worm.  A clutch protects the motor.  You can see the final drive from the end of a row of 16-tooth cogs to the LA (mirrored the other side).
The movement mechanism has an axle sliding in a red 8-tooth cog in between the LAs, with bevel drives to the wheels.
The battery unit (any 4x8x3 one will do) is housed at the rear.  The 12-tooth cog shows the control to a PF LiPo for this prototype but the PU 2-port hub could be used.

The maximum hovering height is about 7cm but the movement function works as soon as the skids have left the ground.
Further flight uses the traditional "swooshing" method.  Walking pace would meet the real 75mph design speed at 1:20 scale!

My hope is that this will help to ensure that we have LEGO Technic civil aircraft of a decent size in the range of sets, seeing as the Osprey would have been around for at least next year, had it not tripped over the "non-military" policy.
As a set, the final CityAirbus model would need to be sponsored by Airbus Helicopters, who own the IP to the real CityAirbus.  They would specify decals to put the livery patterns and brand names on it.

The design and build time was 125 hours over about 5 weeks in August and September, quite a few hours after midnight!

More pictures in my Brickshelf folder
Video on YouTube
Project on LEGO Ideas

Please let me know what you think, and do support and share!

Thanks,
Mark

[msk6003]

Wow that hover and moving mechnisem is great! I want see that on offical TLG model too.

[JintaiZ]

Looks amazing! Supported!

[Brickthus]

On 10/9/2020 at 7:56 PM, msk6003 said:

Wow that hover and moving mechnisem is great! I want see that on offical TLG model too.

Yes, that would be lovely.  I hoped it would add something new to Technic models.  Its maximum height is where the two clear beams are at right angles.

I tested the mechanism with another layer of crossed beams for more height but that was more difficult to keep stable and more complex to make the transmission for the wheels.  I may include that in an update later.

So far they have not chosen to use clear beams, like Anakin's Podracer 75258, in Technic sets but it's a great way to give the impression of unsupported flight!

Support is growing, so I hope we will make the first milestone soon.  Please keep on spreading the word.

Mark

[inzaghi0]

Hello,

This model looks amazing!

Is it possible to receive a part list and instruction for this model to re-build it?

Regards,

Philipp

[Brickthus]

Hi Philipp,

Unfortunately I'm not really into writing instructions.

In the expired LEGO Ideas project there are a few more pictures and a video.

I'll give you a basic list of key pieces:
- 1x PF L-motor, 1x PF LiPo battery unit in the tail
- 2x regular linear actuator (11M compressed size)
- 2x set of gear selector pieces with white 3m axle extender, 3M selector, red lever and pair of red 16-tooth gears.  Mounted one set each side near the front.
    The outputs of those drive the up/down and forward/back functions.
- 4x small turntable, though this version chose not to tilt the rotors as the real CityAirbus uses just differential speeds for manoeuvring.
- A couple of universal joints behind the front piece, to take the motor power up to the rotor drives, 45 degree angle on each one.
4x trans-clear 15M liftarms for the "invisible" lift effect.
- Lots of axle joint #3, which were ordered from Bricks & Pieces.  The rest came from sets but I have bought quite a few aircraft and sets with black and white panels. The latest sets have smaller panels for better shaping.
Most of the rest you can see from the pictures.

Mark

[inzaghi0]

15 hours ago, Brickthus said:

Hi Philipp,

Unfortunately I'm not really into writing instructions.

In the expired LEGO Ideas project there are a few more pictures and a video.

I'll give you a basic list of key pieces:
- 1x PF L-motor, 1x PF LiPo battery unit in the tail
- 2x regular linear actuator (11M compressed size)
- 2x set of gear selector pieces with white 3m axle extender, 3M selector, red lever and pair of red 16-tooth gears.  Mounted one set each side near the front.
    The outputs of those drive the up/down and forward/back functions.
- 4x small turntable, though this version chose not to tilt the rotors as the real CityAirbus uses just differential speeds for manoeuvring.
- A couple of universal joints behind the front piece, to take the motor power up to the rotor drives, 45 degree angle on each one.
4x trans-clear 15M liftarms for the "invisible" lift effect.
- Lots of axle joint #3, which were ordered from Bricks & Pieces.  The rest came from sets but I have bought quite a few aircraft and sets with black and white panels. The latest sets have smaller panels for better shaping.
Most of the rest you can see from the pictures.

Mark

Thank you very much. Then I will try my best to re-build it. 
Might there be the option that I buy the model from you?