Sometimes, a maker builds a tool rather than buying it because doing saves a fortune. A homebrew pick-and-place machine costs a fraction of an off-the-shelf industrial model, as do automated ROM flashing machines and PCB drills.
Other times, though, a maker builds a tool rather than buying it simply for the challenge. Simon Sörensen's latest project is exactly one of these times: building an electric screwdriver out of a battery and hobby servo, following the untimely death of his commercial screwdriver.
Based around a cheap hobby servo - though Simon recommends switching the plastic-gear servo he had lying around for a metal-gear version if you're planning to use the screwdriver in anger - and a USB battery bank, Simon's build has less than $10 (around £8) in parts and no 'intelligence' whatsoever. The power bank - typically a plastic case housing one or more 18650 batteries regulated to a 5V output - provides power to the servo, which is modified for continuous rotation, and a physical toggle switch turns the servo on and off. As the servo runs happily at 5V without burning out or running too quickly, the screwdriver runs at a sensible speed without the need for a pulse-width modulation (PWM) controller in the mix.
With structural integrity largely provided by hot-glue and superglue, though, just how well does Simon's tool work? "With a large powerbank you will be able to use it for many hours before you need to recharge," he explains. "Even though the servo screwdriver is not quite strong enough to handle the larger screws, it still worked great with the smaller ones."
Full instructions for the build are available from Simon's Instructables page.
All of a sudden my electric screwdriver died, but instead of running to the store I decided to build one. So in today's Instructable I'm building a servo driven electric screwdriver using very inexpensive materials. It doesn't take more than 1 hour to build and you can find all the necessary components from Ebay for under 10$! It's a super simple project so let's start building!