Aldebaran-Class : Stock 400 Ton Cargo Helicopter

[Bubbadevlin]

Bubbadevlin Presents

The Aldebaran-Class

KerbalX Link

 

 

Development Process

My first craft using the new Breaking Ground components, the Aldebaran is a large scale helicopter, and to my knowledge the largest stock KSP helicopter. With a dry weight of 200 tons, and a cargo capacity of 400 tons (or 5 of the large 3m tanks) it is capable of hauling all but the most behemoth of loads. 

For its propulsion the craft uses 2 sets of counter rotating props powered by x4 of the large robotic rotors. When i was testing out the robotics parts I realized that much greater power could be achieved if both sides of a rotor were used for the propeller, rather than one. These engines were created by mounting a rotor to freely swiveling servo and then having two counter rotating props attached to each half of the rotor. Using this method one rotor (with properly optimized propellers) can lift up to 75 TONS.

To combine multiple rotors into one engine, I used struts as a method of bypassing the part tree structure. In the case of these engines, each 3m decoupler (used as a propeller ring) has two rotors snapped to it and then strutted to the opposing decoupler.

The other innovation that this craft has is the forward flight engines. Using the BG parts and axis groups was able to give each of the 4 Goliath engines individual gimbaling. This enables much greater stability in forward flight as well as gives the craft unmatched maneuverability for its size.

The main problem I had with this design was that I was unable to properly use the engines in symmetry, and when inversed the rotors seemed to provide less torque.  As a result when flying forward the uneven lift would make the craft very hard to control. This is a reason why the two propellers are clipped into each other on either side, as a way of minimizing the torque from uneven lift.

Flight Guide
Flying this craft is surprisingly simple, with only a few action groups.
1 - Toggle Main Rotors (On/Off)
2 - Reverse Forward Thrusters (No AG to activate, just stage them)
H/N - Control Rotor Torque, acts as throttle for the main propellers

Liftoff is press of a button easy, and landing is achieved just as simply by lowering the rotor torque (~40% is a good landing torque with no cargo) 

In forward flight the max speed is ~70 m/s with no cargo. When going high speeds it is actually beneficial to turn off the main rotor. This allows the rotors to become an auto-gyro relieves the main propellers of uneven lift. Be careful in forward flight however, as the SAS does not utilize the engine gimbal to stay steady, leading to drifting. 

I did not provide any mount for cargo, but it can simply be radially attached to the underside of  the main fuselage. For stability make sure that the cargo is set to auto strutting the root part. 

 

 

 

[The Destroyer]

Wow, didn't expect that kind of lifting capacity from stock rotors. Gonna have to check this one out, maybe borrow that rotor idea.

 

Ah damn, didn't realize it required MH too. Still interesting.

Edited June 5, 2019 by The Destroyer

[Klapaucius]

Nice!!!

For forward flight, are you powering the rotors or just letting them freely spin, turning it into a giant autogyro?

[Bubbadevlin]

On 6/4/2019 at 10:55 PM, The Destroyer said:

Wow, didn't expect that kind of lifting capacity from stock rotors. Gonna have to check this one out, maybe borrow that rotor idea.

 

Ah damn, didn't realize it required MH too. Still interesting.

Thanks! Weird how it requires MH though, i do have the DLC installed but i cant think of any parts from it that I used on the craft

 

On 6/4/2019 at 10:58 PM, Klapaucius said:

Nice!!!

For forward flight, are you powering the rotors or just letting them freely spin, turning it into a giant autogyro?

It works for both ways, though when flying I tend to turn off the rotors once the craft reaches about 45 m/s, and from there out I just let them act as autogyros

[The Destroyer]

The structural panels from MH, there's one on it.