Motors are good for moving objects, but they are all round. Sometimes you need to move something back and forth, and a linear actuator can do that. Although it costs less than $50 online, Michael rechtin really wanted to reinvent the wheel and successfully launched a 3D printing design for less than $20.
The basic design is very simple. It consists of a small motor and uses simple spur gear reduction in several stages. The task of the last gear in the train is to turn a lead screw, which drives the arm of the linear actuator to move back and forth.
For simplicity, [Michael] uses a 24V brush dc gear motor because of its low cost and the fact that it has integrated a step-down gearbox in the design. It works with more 3D printing spur gears to provide greater torque. Instead of a fancy lead screw, a quarter inch bolt, purchased from home depot, can be much cheaper. This will push the 3D printed arm back and forth because there is a nut on the arm. It is wrapped in a neat 3D printing shell. This design can be pushed with about 220 pounds of force. In order to understand its strength more practically, it can easily crush empty soda cans.
The video on the design is great, showing the addition of important functions such as limit switches and how the wiring is neatly hidden in the housing. We’ve seen [Michael’s] work before, such as testing the strength of various 3D printing gears. Play the video after the break.