Posts tagged nxt
KickerBot Design
Jan 18th
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.
Nxt Up, Flying Robots
Jan 13th
Hobbico NexSTAR
Chris Anderson has posted instructions for a NXT autopilot with ideas to have a flying challenge similar to the FLL (grade school) or FTC (high school) competitions that happen on the ground (mostly).
I have a lot of work already lined up to support FRC and FLL here in the Greenbelt community. But, with NASA Goddard 3 miles up the road, we also have a lot of local interest in anything that flies. And I am an ex-pilot…
Maybe this summer…
Remote controlled shooterbot
Jan 3rd
I made the standard shooterbot, the second example robot in the NXT 2.0 kit, and then modified it to be remote controlled. Two motors are used to drive the bot, with the third operating the front mounted shooter. Three sensors are attached; ultrasonic mounted on the front left, color on the upper right, and the Playstation 2 controller interface on the back. The example program has the bot protect a 40 cm circle, giving both a verbal and visual warning before shooting. The first version has a few problems; it advances to give a warning but doesn’t return to the original location, and the gun is inconsistent; it sometimes jams, sometimes shoots twice. I haven’t added any remote control support yet.
Robotics
Jan 1st
Last month I volunteered to mentor students in the FIRST robotics club at Eleanor Roosevelt HS in Greenbelt. I know nothing about robotics, which they will soon discover, but I hope to learn fast and contribute some this year and more next year.
I would also like to help younger kids in grades 4-8; they have a program built around the LEGO Mindstorms NXT though I don’t know if any of the local schools have an active program. So I picked up a NXT kit as my xmas gift to the family.
Eva and I have built the first couple of easy robots, and I’ve played with a playstation remote control and some of the sensors. We’re looking forward to chasing the kittens around the house.