|Making the 2-Liter Soda Pop Bottle Launcher
|Step 1 Cut PVC Pipe
3" 5" 10" 10" 20"
Measure the 4-foot PVC pipe marking lengths of 3", 5", 10", another 10", and the remaining length should be 20 inches. Using a hack saw or pipe cutter, cut the PVC pipe to these lengths. Use a knife, box cutter, and/or sand paper to remove any uneven material from the ends of the pipe segments.
|Step 2 Create Support Legs
Take the unthreaded T-joint and two 10" pipes. One side at a time, apply PVC cement inside the straight-through openings of the T-joint and slip a 10" pipe into each side. Apply PVC cement inside two of the end caps and place them on the ends of the 10" pipes.
|Step 3 Create Main Section
Take the threaded T-joint, the 5" pipe, and the 20" pipe. One side at a time, apply PVC cement inside the straight-through openings of the T-joint and slip the 5" pipe into one side and the 20" pipe into the other. Place on a flat surface. Apply PVC cement to one opening of the 90° elbow. Insert that opening of the elbow onto the end of the 20" pipe, taking care to keep the T-joint and the elbow flat on the surface and pointing in the same direction. Apply PVC cement to the other opening of the 90° elbow and insert the 3" pipe.
|Step 4 Install the Riser
Using the hack saw, cut the threads off one end of the 4" sprinkler riser (about 1/2" of the riser). Remove any uneven material from the end of the riser with a knife, box cutter, and/or sand paper. Using sand paper, sand the last 1-1/2" to 2" of the riser pipe on the end without threads until the pipe has a slight taper. Wrap the riser threads two or three times with Teflon plumber's tape, then tightly screw the riser into the threaded T-joint.
|Step 5 Tight Fit for the Bottle
There should be a snug fit when the 2-liter bottle is placed on the riser; otherwise, sufficient pressure cannot be applied to the launch system. Place a 2 to 3 inch piece of electrician's heat shrink tubing over the riser. Blow with a hair dryer until the tubing shrinks and snuggly conforms to the taper of the riser. Tape the bottom end of the tubing to the PVC pipe using electrical tape (the bottle will sometimes pull the tubing off the pipe if the tubing is not taped). Duct or electrical tape may be used in place of heat shrink tubing, but it tends to not seal as well due to the seams created by the tape overlap.
|Step 6 Install the Tire Valve
Drill a 9/16" hole in the center of the remaining end cap. Insert the valve stem through the hole and fit the valve stem's lip or groove around the hole. Apply PVC cement to the inside of the cap and the end of the 3" pipe. Place the cap on the pipe making sure it is firmly seated; the end of the pipe should firmly press the valve stem's ball against the inside of the cap, thus forming a tight seal.
|Step 7 Attach Main Section to Support Legs
Apply PVC cement to the T-joint in the support legs and to the open end of the main section. Insert the main section into the support legs taking care to align the main section so that the riser is perpendicular (at a 90° angle) to the support legs. The riser should be pointing straight up when the assembled bottle launcher is placed on a flat surface.
|Step 8 Allow Joints to Cure
Follow the directions on the PVC cement. Typically, the cement needs 2 or more hours to cure before the system should be pressurized. The launcher will be under high pressure, and failure to allow adequate time for the joints to set may compromise the system.