This is actually based on a design I built over 10 years ago. Back then it was smaller and power by a weak brushed DC motor. This a complete rebuild using heavier materials a stronger brushless motor. A single servo-controlled front ski is used for steering. I tried using a rudder also but it did not seem to help much. I have made front suspension with a spring, and the rear suspension is just the wires that the skis are mounted to that are flexing. The suspension is a key part of the design to improve stability at higher speeds.
The entire thing is built pretty fast, using 12 mm thick plywood that is mostly glued the screwed together. The skis are made out of 4 mm plywood and are painted with a layer of glossy paint on the underside.
There is still a lot of room for improvement. For example, this vehicle is pretty top heavy. This causes it to tip over easily when turning too fast. The torque from the motor can also cause it to tip over while accelerating too fast or turning to the right. It would probably be a good idea to make it wider and a bit lower.
In any case, it was an interesting project to experiment with!
Click on the image below to make it larger. It shows the vehicle in the same configuration as in the video.
Another video with more winter flying. This time with a few different airplanes. Me and a couple of friends flying at my local RC club: FK Gamen. It is actually pretty uncommon that we have this much snow here where I live. Usually, it just comes a few centimeters of snow that melts away the next day. But this time the weather was perfect. Lots of snow, low winds and sunny.
I found it interesting to experiment with different ski-designs. The planes with smaller skis struggle to stay on top of the soft snow. In the latter part of the video I have made new longer skis for my plane that work better in the soft snow.
Made a set of skis for the Bush Beast 3. This video shows the first few testflights with them.
The skis are made out of 1.5 mm plywood and covered with Oracover on the underside for low friction. I piece of 1 mm piano wire is bent around the main landing gear and makes sure the skis are oriented the right way.
This is a video of my DIY Lidar robot. Here it is using a spinning laser distance sensor (Xiaomi robot vacuum spare part) to drive around and avoid obstacles. The sensor is connected to a Raspberry Pi running a Python script that is the main behavior program. There is no mapping going on, the robot is just going forward and turning away from things that are to close. The Raspberry Pi then sends serial data to an Arduino that controls stepper motors driving the robot.
The Teensy 3.2 is running PID speed control for the DC motor that spins the sensor. It is also reading the binary sensor data and sends it in easy to understand ASCII-messages over serial to the Raspberry Pi. The sensor spins at 5 revolutions per second and makes a distance measurement for every degree. Resulting in 360*5 = 1800 measurements per second. The accuracy is within a few centimeters. This sensor trigonometry to measure distance, in that way it is not a real Lidar sensor.
I have re-built my old balancing robot using a single Arduino Mega instead of my previous solution using three different Arduinos. A better more optimized solution. Schematic and source code is available on the robot page here: http://axelsdiy.brinkeby.se/?page_id=1845
Here is a video of me assembling the main electronics board used in my Bush Beast 3 RC airplane.
A Teensy microcontroller is used to read a decode an S-bus signal from the receiver and make all the servo signals. It manages servo mixing and gyro stabilization, as well as controlling LED lights on the plane.
More info about this, including schematics and code can be found on the Bush Beast 3 page here: Bush Beast 3 page
I got myself two new airplanes this summer at an RC plane auction that was organized at my local RC flying club FK Gamen.
The first one is a J3 Cub ARF model by Thunder Tiger with a wingspan of about 2.2 meters. The model came with a 4-stroke nitro engine that I have replaced with an electric power system. I will make a new landing gear with suspension and fix the motor cowling. I will probably add some kind of gyro stabilization also, this plane is surprisingly unstable in windy conditions.
The second plane is a Flair Magnatilla. The wingspan is about 1.6 meters. This is my first airplane with a nitro engine. A 4-stroke Saito. I will probably add a steerable tailwheel and make a few other adjustments over the winter.
Bush Beast 3 is an RC bush plane that I have designed and built during this winter. The plane is built using balsa wood and covered with Oracover. The design of this airplane a combination of Trent Palmer’s Kitfox, the Pilatus Porter, and various Cub planes.
I have made a custom electronics system on this plane. A Teensy 3.2 microcontroller reads the S-bus signal from the RC receiver and controls all the servos, it also applies 3 axis gyro stabilization and manages all servo mixing and a custom lighting system. More about that in a future video.
I fly my RC Airplanes and quadcopters on LiPo batteries like most other people. But LiPo batteries have several disadvantages. The biggest problem is that their life is pretty short. They usually don’t last more than 100 cycles. Therefore I wanted to explore the possibility of using 18650 cells to power my RC models instead. I while ago I got myself a cheap battery spot welder from China and a couple of genuine LG HG2 cells.