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

Kuroko (thesencoredstudio) from Steam asked me about landing gears. Three Rules of Rigidity Basically when I build landing gears I follow the Three Rules of Rigidity . 1. Less Blocks Every block has a connection, the less blocks the less bendy connections. 2. High Scale Make the blocks in the landing gear as big as possible, because flimsy blocks are bendier. 3. High Mass Attach the landing gear to high mass blocks, e.g. scaling blocks or ballasts which can set mass value. My Conventional Setup Usually I simply use a suspension and the wheel to make each gear. If the landing gear is retractable I just put a steering hinge there. Fixed landing gear Fixed tail gear grabber or suspension both work Retractable landing gear Retractable nose gear Examples of Different Setups When there's a different configuration, I have to create a new setup. Main Gears of Su-34 Fullback This is the main landing gear of my Su-34 Fullba

The Dassault Mirage 2000-5 replica is uploaded to the Steam Workshop here . About the payload induced CoM shift, my solution is to add negative power water cannons (nives) inside the missiles' rockets. They are bound to the same key as the plane's engine. The thrust of the nives negates the pitch down effect. And when a missile is launched the heated nives gives extra boost. These special missiles work perfectly. The only drawback is the one extra block. #

 As I struggled to make this plane fly right, I discovered a method to shift the center of lift (CoL). In the previous post I wanted to balance the torque generated by the lift propeller blocks (CoL) and the flat propeller blocks (CoA). now I have a promising trick to solve the problem. Have a look at the pictures bellow. By raising the thrust, the CoL can be moved forward. low thrust axis generates torque for pitch up  thrust axis that go through the center of mass generates no torque move CoL forward to balance it out raising the thrust axis move the CoL to balance it out. In the case of my Mirage 2000, the situation might be the same as the first picture. When speed increases, the torque generated by CoL and CoA goes up while the torque from the thrust axis stays the same, causing the plane to pitch down. I'm very happy to find a generalized method for Besiege plane tuning. There's still the plane balance problem when carrying payload

Notes of Delta Wing Tuning I built this plane twice. The first one has stability problem and didn't look quite right so I built another. Here is the stability problem. It flies alright at medium speed but pitches down badly at high speed. I thought positions of the center of lift (CoL) and the center of aerodynamics (CoA) was the problem. While I usually build the whole plane with flat propeller blocks then add 20° lift propeller blocks after, CoL and CoA are clearly separated. In this case CoA is decided by flat propeller blocks and CoL is decided by the lift propellers. Note that lift will increase as the speed builds up. So when the CoL is ahead of the CoA, it should pitch up at high speed, while is CoL is behind CoA it should do the opposite. My plane might be the latter. pitches up pitches down might be balanced So I came up with this solution, angling up some of the flat propeller block in the front. The new plane flies okay now. In theory it