[James] makes some seriously awesome Iron Man props. In one of his latest helmet builds, he came across a handy hack to lock the faceplate servo in place.
You see, as awesome as it is walking around like Iron Man all day, you’re going to want to keep your faceplate up for extended periods of time. Simply holding the servo in place electronically is a waste of power, and results in the annoying sound of a servo under strain. On the other hand, cutting power to it will keep it in place momentarily — but it will also start to close under the force of gravity.
The solution is actually quite simple, by reprogramming the Picaxe-08M microcontroller, the board now shorts the motor terminals to hold it in place. This is called magnetic motor braking, and it works by creating a closed loop that makes it much harder to induce a current under load. We once added this feature to a motorized push-scooter — it’d stop on a dime, although you wouldn’t…
Stick around after the break to see an extremely in depth video on how he setup the entire system.