To begin, a picture of the final blaster.
It uses no glue, screws, or adhesive, and all parts can be bought from a hardware store for under 20 dollars, with the exception of tools.
2.75" of draw, but at whatever spring strength you want. I can put a fully compressed Hillman/Everbilt #69 spring in it, without any issues.
Ranges are about the same as any other primary out there, ESLT, SNAP, +bow, etc.
Easiest thing I've ever built, which includes building a slingshot.
1 3/4 in. x 3/4 in. x 1/2 in. PVC Sch. 40 S x S x S Reducing Tee
1 1/4 in. x 3/8 in. x 1/2 in. Bronze Flange Bearing
1 4.625 in. x 1.25 in. x 0.12 in. Zinc Compression Spring [Or other suitable compression spring]
2 1-3/8 in. x 1-1/8 in. x 1/8 in. Buna Rubber O-Ring
1 1/2 in. CPVC CTS 90-Degree Slip x Slip Elbow
1 3/4 in. Schedule 40 PVC Plug
1 60:25 Caulk Gun [Or other ~3 dollar caulk gun. I've found these at Big Lots, so lots of options here]
1 1-1/4 in. x 2 ft. PVC Sch. 40 Pipe
1 1/2 in. x 2 ft. PVC Sch. 40 Pipe
1 1/2 in. x 260 in. PTFE White Thread-Seal Tape
1 3/4 in. x 1/2 in. Schedule 40 PVC Reducer Bushing
1 1/2 in. x 2 ft. White PEX Pipe
Cut 7.25" of 1-1/4" PVC off of the 2' stick
Cut off the ends of the 3/4"x3/4"x1/2" reducing tee so there is 1" of pipe from the center line to the 3/4" ends
Cut the smaller end off of the 3/4 in. x 1/2 in. Reducer Bushing, so that it is only .75" long
Place an o-ring on the bushing, and push the bushing into one end of the tee. Take off the o-ring, and wrap the gap with teflon tape, 7 wraps should suffice.
Cut off a .5" ring of 1/2" PVC, and place it inside the other end of the bushing. Take .5" of 1/2" PEX, and push it inside of the 1/2" PVC.
Wrap the flange bearing in teflon tape, or in my case, surgical tubing, and push that inside of the PEX
Take this nested piping and push it into the other end of the tee
Take one of the rings of 3/4" PVC coupling from the tee, and place it on the 3/4" PVC plug
Place an o-ring on the 3/4" PVC plug, and wrap teflon tape in front of it to keep it in place
Place the spring inside the 1-1/4" PVC
Place the plunger head in front of the spring, with the larger side facing the spring, inside of the 1-1/4" PVC
Place the tee inside of the 1-1/4" PVC, facing the plunger head
Unscrew the nut from the caulk gun, and remove the metal washer. Pull the rod out of the caulk gun, without squeezing the handle
Place the plunger assembly into the caulk gun, and replace the metal rod.
Thread the nut back onto the rod, using your fingers, or if necessary, pliers.
Wrap the 1/2" CPVC elbow with teflon tape, then push into the 1/2" hole of the tee
Cut a 1' section of PEX, and place it into the end of the elbow
Some extra assembly photos
Questions, comments, flames?
Edited by mysterio, 12 December 2015 - 08:57 PM.