I needed a small linear actuator (a mechanism for creating motion in a straight line) for a project and was finding only oversized or cost-prohibitive solutions. Industrial automation actuators have plenty of muscle but rarely come in small packages. Hobby linear actuators come with a smaller footprint but can be costly. I’ve often wondered about the load capacity of the screw and nut contained in a standard lip balm tube, so I collected all the lip balm tubes I could find and started testing.
One stood out over all the others and could exert over 10 pounds of thrust with a 1.25″ stroke: the mighty Blistex tube. No other lip balm screw-and-nut assembly comes close to carrying the same load as a Blistex tube. Add a magnet to the shaft and a couple of reed switches to the case, and you’ve got an actuator with limit switches at each end!
MAKE Volume 34: Join the robot uprising! As MAKE's Volume 34 makes clear, there’s never been a better time to delve into robotics, whether you’re a tinkerer or a more serious explorer. With the powerful tools and expertise now available, the next great leap in robot evolution is just as likely to come from your garage as a research lab. The current issue of MAKE will get you started. Explore robot prototyping systems, ride along with the inventors of the OpenROV submersible, and learn how you can 3D-print your own cutting-edge humanoid robot for half the price. Plus, build a coffee-can Arduino robot, a lip balm linear actuator, a smartphone servo controller, and much more