Sport Rocketry

6 MAY/JUNE 2022 SPORT ROCKETRY Finished rail pad just before its first use. by Bernard Cawley NAR 89040 In the last few years, as e American Rocketry Challenge has phased out the use of 1/4" launch rods in favor of 1010 rails, one of the challenges for new teams has been finding a rail-equipped launch pad. Commercial pads start at a little over $200 plus the rail itself and go rapidly up from there. On the Internet are some rail pad de- signs using PVC or ABS pipe for the base, but most of these are not adjustable for an- gle, and most have four legs and so aren't nicely self-leveling on the ground like a tri- pod is. I'm a fan of PVC tripods for low power pads and have built several over the years. What kept me from scaling up to a larger such tripod that's robust enough to support a rail was the lack of availability of a pipe fitting called a side-outlet elbow, which is the bit that forms the top of the tripod, in sizes for pipes larger than one inch. Sure, there are ways to make a sort of tripod us- ing an assemblage of elbows and tees, but this is a long way from the elegance of a simple tripod. en, in late 2016, on Ama- zon I came across "furniture grade" fittings like this for two-inch pipe from a company called FORMUFIT. at was something that could form the basis of a good solid tripod large enough and strong enough to handle a six-foot 1010 rail and mid power rockets like those in TARC competition. I ordered a package of these fittings from Amazon (they were being sold in packs of four) and proceeded to see if I could make tripod pads for a couple of local TARC teams, as well as add a rail pad to my own club's GSE. I much prefer to be able to adjust the launch angle at the pad. It's not always calm and the ground, even at the soccer fields where most TARC flights in my area take place, isn't perfectly level. is led me to try a few adjustability approaches for this 2" pipe tripod including a spectacular failed attempt to scale up the two-eyebolt- Build an Build an Inexpensive Mid-Power Inexpensive Mid-Power Adjustable Rail Pad Adjustable Rail Pad Build an Build an Inexpensive Mid-Power Inexpensive Mid-Power Adjustable Rail Pad Adjustable Rail Pad

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