Issue link: https://www.e-digitaleditions.com/i/1466727
10 MAY/JUNE 2022 SPORT ROCKETRY top. I actually drill a 1/8" pilot hole using a Dremel drill-press attachment for my old corded Moto-Tool. en, using a barb- point 1/2" bit, I can drill the pilot hole out to 1/2". On the bottom you can center the 1/2" drill bit pretty much freehand in the Materials List Tripod: 1 10' piece of 2" ABS or PVC schedule 40 pipe (you will use about 76" of this for one pad) 1 10' piece of 1½" ABS or PVC schedule 40 pipe (you will use 44" of this size pipe for one pad) 1 FORMUFIT 2" PVC 3-way elbow fitting (F0023WE) (formufit.com) or similar 3 2" PVC male terminal adapters (for electrical conduit - Carlon E943JRR or similar) 3 2" PVC female threaded adapters (for electrical conduit - Carlon E942JR or similar) 2 1½" PVC slip-fit pipe caps 1 2" PVC slip-fit pipe cap 4 1/4-20 x 1/2" thumb screws 1 1/2" hex bolt or carriage bolt at least 8" long, with threads that go to within 3" of the head 1 1/2" hex nut or lock nut 1 1/2" washer 2 #20 (or a little larger) worm drive hose clamps Blast deflector: 1 stainless steel dough cutter/scraper from Dollar Tree (or similar) 2 1010 rail buttons 1 8-32 x 2" machine screw 4 8-32 hex nuts ends a little bit. Next, cut two 22" long pieces from the 1½" pipe and chamfer the cut-off edges. ese are the inner portions of the adjust- able legs. Cement the caps on one end of each of the 1½" legs, and on one end of the 2" leg. Set these aside. Prepare the FORMUFIT 3-way elbow by drilling a 1/2" diameter hole through the center. e tricky part of doing this is getting the hole in the right spot on the depression between the three arms of the part. It is kind of awkward restraining it while you do this, however. If you have a drill press that can take a 1/2" bit you can probably just drill all the way through from the top, but I've not tried this. Now take the 1/2" diameter bolt and feed it up from the bottom though the 3-way elbow. Put the washer on it then Top fitting with threaded adapter assemblies ready to cement into place. Above: Tapping a 1/4-20 threaded hole for leg adjustment thumbscrew. Below: 1/4-20 thumbscrews for adjustable leg installed.