LIMS Air Hockey Table
Air Hockey Table Specifications
Manufacturer: KT Sports Dimensions: 79” long 39” wide (inner table dimensions) Hole spacing: 1” square intervals Number holes: 79 x 39 total holes on table (before modification)
Modifications: covered 2x12 columns (12x79) on each side of table with clear packing table directly applied to surface of table. Left uncovered 79 holes x 15 holes down center of table (long-ways)
Shop-Vac Specifications
Manufacturer: Shop-Vac Corporation Name: Ultra PRO Model Number: 92L500A 12 Gallon 5.0 Hp 2” inner diameter flexible hose Hose attached in blower mode, taped and held in place underneath table at plenum.
Pressure Measurements
Experimental Setup
1/4” hole drilled into bottom of plenum, 6” to the side of main blower intake 1/4” clear plastic hose inserted via press-fit into plenum (3/16” inner diameter) Shop vac hose taped and held in place over plenum intake In blower mode, our shop vac appears to be leaking extra air out through various extra vents. To test the impact of the extra leakage, we performed one test with the shop vac in standard blower operation, and a second test with the extra venting holes covered with tape.
Test 1: Water Column
Vertically displaced 5” of water in a 3/16” inner diameter flexible clear hose (10 ft long) 1 inch water = 0.036 PSI With Shop-vac vents unblocked: 4 inches water displaced * 2 * (0.036 PSI/inch) = 0.288 PSI in plenum With Shop-vac vents blocked (taped): 5 inches water displaced * 2 * (0.036 PSI/inch) = 0.36PSI in plenum
Test 2: Analog Differential Pressure Sensor
Model Number: ASCX01DN Sensitivity: 4.5 Volts / PSI
One input to pressure sensor connected to 3/16” inner diameter clear plastic hose (6” long, with other end in plenum) Second input to pressure sensor open to room atmosphere With blower off: Measured Offset Voltage of Sensor = 0.293 Volts
Blower on, Shop-vac vents unblocked: 1.29 Volts / (4.5 Volts/PSI) = 0.285 PSI Blower on, Shop-vac vents blocked (taped): 1.51 Volts / (4.5 Volts/PSI) = 0.33 PSI
Tabulated Results
Flotation Capability
Experimental Setup
From the results of the pressure test, we covered the extra vents on the shop vac. This results in a higher pressure in the plenum and should increase the amount of weight we can support. Shop-vac connected in blower mode with extra vents taped over. Shop-vac taped and held in place at plenum.
Results
We tested 2 different sized clear polycarbonate circular discs (6” diameter, 8” diameter). 6" disc can support ~1.5lbs before it begins to drag 8" disc can support ~4.85lbs before it begins to drag
