A prototype device to lift up a frisbee that is lying on the floor. It can also pick up a frisbee that's lying upside-down. Intended to be actuated using a pneumatic piston, and mounted on the end of an arm of some sort. Technical description below.
Bob Rudolph, FRC Team 2170, Glastonbury, CT
bob@rudolphlabs.com
Technical details:
===================
Parts:
-Toilet plunger
-Wooden dowel
-Grease
-Scrap wood block, about 3/4" thick
Construction:
1) Chop off the shaft of the plunger, leaving it about 4 inches long.
2) Drill a hole (with diameter equal to that of the wooden dowel) through the center of the plunger shaft.
3) Just above where the rubber ends on the plunger shaft, drill several small holes laterally through the plunger shaft.
4) Drill a hole (with diameter equal to the outside diameter of the plunger shaft) into the center of the scrap wood block.
5) Glue the plunger shaft into the scrap wood block, so that the small holes are not covered, and the end of the shaft that you cut is flush with the surface of the scrap wood block.
6) Coat the inside of the shaft with grease.
7) Insert the wooden dowel into the shaft.
Why it works:
The small holes, along with the dowel, creates an air valve. When the dowel is pushed down into the shaft, it blocks the small holes from the inside, which keeps any air from entering. You can then "plunge" the frisbee, and suction is maintained since no air can enter. If you then pull the dowel out so that the air holes are not blocked, it allows air to enter the rubber chamber, destroying the suction seal and releasing the frisbee. The grease is there to make the seal between the dowel and the inside of the plunger shaft air-tight.
I added a nice handle and guide with two bolts and a strip of hacksaw blade, but that's just for demo purposes. On the robot, you would use a pneumatic piston to actuate the dowel valve.
