Besiege Notes on Propeller Engines

Kuroko (thesencoredstudio) from Steam requested a talk about propeller engines.

There are a few things you can do to get the most potential out of propeller engines. I suppose the reader knows some advanced stuffs like Besiege plane building experiences and flatangle propeller blocks, also basic aeronautics .

The Angle of Attack (AoA)

The 90° flatangle is ideal if the plane is going to fly supersonic, but I recently build only 1:1 scale WWII fighter planes with top speed below 200 m/s. 75° to 80° AoA is what I usually use.

The Radius

I follow the specifications when I build replicas. If its an original aircraft, it is of course the bigger the better.

The Number of Propeller Blocks

In Besiege, the propeller blades are made of propeller blocks, the vertical and horizontal stabilizers are also made of propeller blocks. It'd be an un-flyable plane when the stabilizing effect of the propeller is stronger than the tail's. Remember to add propeller blocks to the tail when making a double prop engine.
But before trying to add power by doubling the propeller blocks, try clocking up the rotational speed.

3 blade double prop

The Speed

Torque, Numbers vs. Reality

Two of the Law of Rigidity says high scale and high mass, they also work for the wheels' and cog's rotational speed. As the scale and mass they attach to get smaller, the real speed becomes smaller too.

coaxial engine, the big powered wheels attach to the ballast inside
it barely produce any thrust when the mass is 0.1.

Sometimes the engine has the maximum wheel speed but still seems weak. Try add one or two more reaction torque braces, it may just lack some torque.

3 braces for reaction torque

Axle Support

Attach swivel or unpowered wheel to the block which the propeller blocks attach to. The wheel speed can go faster with extra axle supports.

ball joint axle support, usually adds around 2 to speed
small wheels also means the speed numbers need to be higher

when the propeller blocks attach to a x2 mass ballast, the plane can
fly well with only one blade
the big wheel

Not the Engine But the Plane's Scale & Mass

Do you know a bigger plane in Besiege is lighter and faster?

Every block in Besiege except ballast and scaling block has fixed mass that don't scale with its size. A bigger plane usually has more power but doesn't have as much blocks as it seems to, in other words the density is usually lower. So a bigger plane that has a lower mass relative to its scale accelerates faster than the smaller one.

And as a reminder, keeping the plane low-mass and low-block-count are as important.

#