The entire project is mostly made by using parts, I already have lying around. This is the simple version and will be expanded later in a new version supporting e.g. double tapping etc.
The mechanism itself is dived into several parts:
Actuators
The actuators are used for raising the targets after having been hit by shots. Basically, these are linear actuators moving an arm, which either raises a single target or an entire row of targets. The actuator is made by having a motor (stepper in this case) move a slider using a threaded rod.
Arm
The arm in the project is made in order to perform tests on a single target.
Sensor
The sensor is basically a switch, which registers the target falling. In the final version, this will be a switch with a long arm. In the test version, I use a tiny switch on a 3D printed fixture, but the principle is the same : a switch indicating a targets falling.
Light fixture
A fixture for holding a 12 v LED light in an angle lighting up a target.
Controller board
The controller board is a Raspberry Pi hat for reading the keys, switching on/off the lights and controlling the stepper motors.
Software Package
The software is divided into 2 parts: an onboard software package for running the controller and the Android App (sorry Apple users) controlling the board.
The Android App is only used for sending messages to and from the board, so this will be described later on, but for now Python / C# test programs are to be used instead.
The controller software is to have the following features:
- Registering a fallen target (reading the switches)
- Lighting the target (switching on the lamps)
- Controlling the stepper motors
Later on, the software will get more features:
- Automatic homing of the actuators
- Automatic point counting
- Delayed lighting for running sequence shooting and shoot/no shooting scenarios
The Android software is to get the following features, but will be extended if time allows me:
- Sending commands to and retrieving status from the controller board
- Creating shooting scenarios
- Storing the previous results, thus creating statistics of the shooting and own progress
- Since data is only saved on the users' phone, then the GDPR shouldn't be a problem
Torque isn't the problem here. There are several things here, which can limit the speed :
Some idiot decided to put all I/O on the MCP23017, which reduces the throughput of pulses.
Same idiot decided to write the test in Python and not using C/C++.
I guess, that the same idiot (me 🤣) should get his act together and spend less time on building custom knives and rewrite the software in C/C++ before attempting to redo the hardware.
The actual load on the motor is very small, so torque isn't an issue.