The Super Wheel Launcher is a device built out of the LEGO® Mindstorms NXT that is designed to launch a wheel at a specified angle. The robot does this by spinning a wheel at about 38 revolutions / second and releasing the wheel down a ramp after it spins for 10 seconds.
On this page, you will find information about how the wheel launcher works and how a user operates the robot. At the bottom of the page is a video of the Super Wheel Launcher.
Here are some photographs of the wheel launcher:
Operation of the Super Wheel Launcher
This is the wheel that the machine is designed to launch. The wheel is on an axle. The axle has two 12-toothed gears attached to it, one on each side of the wheel.
The trajectory of the wheel's launch can be adjusted by using the left and right arrow buttons on the robot's controller (You will see this when you watch the video below.). In response to pressing the left or right arrow button, a motor connected to an adjustable trajectory ramp will decrease or increase the angle of the ramp with respect to the floor.
The wheel is placed between an upper and lower set of parrallel tracks. To lock the wheel in position, a latch is then manually closed until a motor connected to the latch fully closes and locks it. The latch holds the wheel with two pins that push the gears on the wheel axle against the 40 tooth drive gears.
The wheel spins for 10 seconds before it is released. The motor that spins the wheel is connected to a gear system, which has an overall wheel to motor ratio of 50 to 1 (40/8 * 24/8 * 40/12 = 5/1 * 3/1 * 10/3 = 50/1). Within 10 seconds, the motor reaches a maximum speed of about 0.75 revolutions / second. The wheel reaches a maximum speed of about 0.75 * 50 = 37.5 revolutions / second.
After the wheel spins for 10 seconds, the motor controlling the latch turns the latch so that the pins locking the wheel in position turn upwards. The rapidly spinning wheel slides down the the lower set of tracks, and it reaches a fixed platform where it gains velocity and accelerates up the trajectory ramp.
The wheel can be launched over small objects such as the plastic box in the picture to the right.
Video of the Alectric Labs Super Wheel Launcher
This video continuously loops. Click anywhere on the center of the video to end it.
