Archive for January 18, 2010

KickerBot v1

Here is my partially complete robot designed to kick a small ball using rubber bands as the energy source, powered by a rear mounted winch. At our Saturday FRC team meeting, we watched a video of a ball kicking mechanism. I believed it used a rack and pinion device to cock the leg back which then, lacking a lock and trigger device, kicked automatically. I don’t have the lego pieces for rack and pinion (sigh), but a winch should work, using a rubber band to return the winch to the start position.

This is my first design from scratch. I had built the ShooterBot which uses a front mounted piston to shoot small balls out of a magazine rack. The magazine is a plastic piece designed to require a certain amount of force to release the ball through the front hole. The arm of the “piston” is actually stationary, the motor/servo moves the entire ball magazine across the length of the piston arm. I’m sure there is a better technial name for that.

This guy has a “leg” hanging just below the front edge of the NXT brick. As the winch pulls back on the leg, rubber bands (not shown) are stretched. As the leg rotates up, the cocking mechanism (not built yet) will eventually lose grip of the leg and the bands will shoot the leg forward. A different band will then pull the cocking mechanism back into place as the winch unwinds.

This design is currently top heavy and unstable; the frame needs more work. But I didn’t want to build anything else until I got the cocking mechanism completed. But I might move on to building something else now that I see that I can use a motor as a simple winch. I’m more (much more) of an idea guy than a mechanical engineer. I also have a terrible time finishing projects. Hmmm.