Vacuum Suction Testing
Since the ball may only roll 3 inches into the robot, we wished to study the plausibility of a vacuum holding system. In the 2008 Overdrive game, Team 1771 successfully used a mini shop-vac impeller driven by two Fisher Price motors, to posses and lift the 8lb track ball. For our test today, a Shop-Vac brand “Hang-Up Mini” model was used. This is a 120VAC 6.2A model. As shown in the picture below, the impeller is approximately 4 inches diameter, one half inch thick, and very light weight.
After reassembling the vacuum, a plastic funnel of approximately 4 inches diameter was affixed to the hose. A small basketball and a rubber exercise ball were used for the test (no soccer balls available at testing location). No seal was used around the lip of the funnel. The vacuum held the small basketball very well, and the large exercise ball moderately well. While seams in the balls did not greatly affect the holding power, we speculate a larger funnel with a lip seal/gasket would improve the results greatly.
A video of the test is shown below:
(There was a video here that has sadly been lost in the archives.)
We have not yet determined exactly how a mechanism like this might integrate with a kicker.
We also observed the suction power directly from the impeller housing:
(There was a video here that has sadly been lost in the archives.)
The testing revealed the vacuum produced greater suction and holding power than expected, and could potentially be a successful soccer-ball holding device. Further tests would have to be done to power the impeller with KOP motors (such as two Fisher Price motors, as 1771 did in 2008).
