Winter flying with skis

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.

Lidar Robot

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 Xiaomi laser distance sensor is connected to a Teensy 3.2 running code from this project:

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.

Bush Beast 3 electronics

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

There you can also find some build-images

Two new airplanes

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.

Video: Bush Beast 3

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.

Li-Ion Batteries for flying RC models

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.

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DIY motorized roller blind

This video shows my DIY Motorized roller curtain. It is driven by a stepper motor. An Arduino Nano is used to read IR signals from an old TV remote and control the roller curtain.

EasyEDA project with schematic and PCB layout:

Arduino code:

3D printed STL parts:

Rebuild of my “original” balancing robot.

This is the first self-balancing robot that I built that actually worked well. More info about it here. My absolute first self-balancing robot was the “Equaipose bot”, link the page about it here.

This video has gained some attention on youtube, and I think that is why I get at least one email every other week from people asking about the code and schematics for this robot. I have not shared the code of any details about this robot since it is very poorly made and coded. The robot uses multiple Arduinos just to keep the balance and drive the motors, later I also added another Arduino to manage the Ultrasonic sensors and some other stuff. There was also a Raspberry Pi that I planned to use for computer vision experiments, I never came around to doing that using this robot.

Now when I know a lot more about self-balancing robots, and Arduino programming and DIY robots in general, I decided to make a new version of this robot. I new complete rebuild of it. My intention is to make the robot less complicated and also better. I stripped down almost everything in the robot and started over. Still using the same old wooden chassis. The new version is based on a single Arduino MEGA R3 controlling everything in the robot. It reads the MPU6050 IMU, makes all the filtering and balancing calculations, and drives the motors using hardware timers for maximum precision. The new code for this robot is heavily based on the code for my “mini balancing robot”, with some improvements, more info about that robot here. I still use the same old stepper motors, model airplane wheels, and “Big Easy Driver” -stepper motor driver boards. The Arduino MEGA also controls and reads four HC-SR04 ultrasonic sensors using Interrupts. Those sensors are used for obstacle avoidance.

The new version of the robot works now. It balances and drives around avoiding obstacles, but I still have a few things to fix with the code. I want to add a pushbutton for control and a buzzer for feedback, I should also add battery measuring and implement a low voltage cut off to prevent damage to the battery.

I hope to release I video of the robot together with the code and schematic in a couple of weeks.

The servo seen in the pictures is not and will not be implemented in the first version of the code, but the intention is that the servo should be used to make it possible for the robot to raise itself up and start balancing on its own. Maybe I will also ad some sort of remote control since it is a frequently requested feature, But that will be in a later version.