RC servos are handy when you need to rotate something. You can even modify them to rotate continuously if that’s what you need. However, [Roger Rabbit] needed linear motion, but wanted the simple control afforded by an RC servo. The solution? A 3D printed housing that converts a servo’s rotation into linear motion.
The actuator uses five different parts, a few screws, and a common RC servo. The video shows the actuator pushing and pulling a 200g load with a 6V supply. There’s some room for adjustment, so different servos should work.
We were wondering about the STL files; [Roger Rabbit] offers to send them if you e-mail. We asked and they have been posted to a GitHub repo. There are also a few similar designs on Thingiverse if you want to try a different set of parts, although many of those use stepper motors.
We’ve seen some homebrew linear actuators before, but the attractive part to these is how easy it is to control the RC servo with a pulse width instead of requiring an H-bridge or stepper motor controller. Just the thing for feeding that cat while you are on holiday.