Scratch El Cheapo Launch Pad Original Design / Scratch Built

Scratch - El Cheapo Launch Pad {Scratch}

Contributed by Mike Goss

Manufacturer: Scratch
(Contributed - by Mike Goss - 03/20/05) El Cheapo launch pad

Brief:
This is the culmination of several years of trying to come up with a cheap, easy to transport Launch pad that can hold the launch rods to keep them from being bent while you are getting to your launch sight. This is your basic three legged launch pad with a tilt head, robust blast deflector, and launch rod storage all in one convenient package. It can be assembled with simple hand tools and a 10-32 tap. I cannot claim any responsibility for the ideas that are used in this design. So to give credit where credit is due, the PVC stand is a knock off of the Quest launch pad, the blast deflector is an idea from Jim Flis (of FlisKits) and the swivel is from a design called the "Plumber's Delight" launch pad. I hope that by putting all of the ideas here together will help others in their search for a good, cheap pad.

Construction:
All of these parts can be found at your local home improvement or hardware store.

It consists of:

  • 1 3/4" PVC Pipe 4' long
  • 1 3/4" PVC 3 way coupler, one way 3/4" threaded, two ways smooth
  • 1 3/4" PVC straight Coupler smooth both sides
  • 1 3/4" PVC straight coupler to 3/4" threads Male
  • 1 3/4" PVC straight coupler to 3/4" threads Female
  • 1 3/4" PVC Cap
  • PVC Cement/Cleaner
  • 1 3" 1/4"x20 EyeBolt
  • 1 2" 1/4"x20 Eyebolt
  • 3 1/4"x20 Nuts
  • 1 1/4"x20 Anti-Vibration Nut (plastic Insert)
  • 3 1/4"x20 Washers
  • 1 10-24 x 1" Thumbscrew
  • 1 10-24 Wing nut
  • 3 1/4"x 1 1/4"Fender Washers
  • 10 10-32 Washers
  • 1 1/4"x20 threaded rod Coupler (Long nut)
  • 1 10-32 x 3/4" Thumbscrew
  • 1 Square galvanized metal duplex outlet cover
  • 1/8" x 36" stainless steel rod

Tools required:

  • One 10-32 tap with drill bit
  • Tap Wrench (holds 10-32 tap)
  • Small Triangular file
  • 1/4" drill bit and drill
  • Hacksaw
El Cheapo launch pad

Base assembly:

First take the 3-way PVC junction and drill a 1/4" hole through the center of the junction of the pipes. Set the junction so it "stands" on it's own three legs and drill straight down. Next, cut the 4' length of 3/4" PVC pipe into three roughly equal lengths with the hacksaw. If they are an inch or two off, it will not matter so don't sweat it. Now take the three pipe pieces and using the PVC Cleaner and cement (please follow the instructions printed on them) to attach the fittings on as follows:

Piece # Top Bottom
1 3-way junction Threaded female
2 threaded Male smooth coupler
3 nothing 3/4" cap

Set these pieces aside for now.

El Cheapo launch pad

Swivel assembly:

Take a look at the exploded and assembled swivel pictures. The idea is to have the thumbscrew and wing nut tighten down on the eyebolts to hold them in place, The fender washers help the assembly swivel, and the regular washers keep the thumbscrew centered in the large eyebolt openings.

Take the 10-24 x 1" thumbscrew and stack on components to it in this order:

  1. 10-32 washer
  2. Fender washer
  3. Eyebolt
  4. 4 10-32 washers (these will nest inside the eye of the eyebolt)
  5. Fender washer
  6. 4 10-32 washers
  7. Eyebolt
  8. Fender washer
  9. 10-32 washer
  10. Wing nut
El Cheapo launch pad

Tighten the wing nut. The swivel assembly is now complete.

Final assembly:

Take one of the 1/4"-20 nuts and thread it completely onto the long eyebolt and tighten. Insert the long eyebolt into the hole that was drilled into the top of the 3-way PVC junction. Lightly thread another 1/4"-20 nut onto the bottom of the eyebolt that is now protruding into the middle of the three "legs" of the junction. Do not tighten this too tight as it will crack the PVC junction. Tighten the nut until the swivel will not spin in the hole but not so tight as to crack the PVC junction. Now add the anti-vibration nut to the bottom and snug it tight to the nut already on the eyebolt. This will keep the assembly from moving.

Drill a 1/4" hole in the galvanized outlet cover near the center of the metal. Take the drill bit provided with the 10-32 tap and drill a hole completely through the coupling nut approximately 3/8" down from one end. Put the coupling nut into a vise and use the 10-32 tap to thread the hole that was just drilled. Take the triangular file and file a notch in the inside threads of the coupler on one side where the hole was drilled. This will help keep the launch rod stable in the coupler. On the side opposite of the filing, thread in the 10-32 thumbscrew. This is now the holder for the launch rods.

Now on the eyebolt that is sticking up from the pad, thread on a nut and add a 1/4" washer. Add the cover plate that is now a blast deflector, another 1/4" washer and finally add the long end of the threaded coupler that is now the launch rod holder. Thread the launch rod holder on three turns, and then tighten the nut on the underside of the blast deflector until the assembly is tight.

The assembly of the launch pad is now complete. Now the pad can be assembled for launch or transport. For transport, stack the three PVC sections, one junction is threaded, and the other is slip fit. Insert the launch rods inside this assembly and thread the sections together.

El Cheapo launch pad For launch, unscrew and pull apart the legs from each other and pull out a launch rod. Insert the threaded leg into the threaded hole on the 3-way coupler and the other leg into the remaining hole. Take a launch rod and insert it into the launch rod holder on the top of the unit and tighten the 10-32 thumbscrew. Adjust the angle of the launch rod with the 10-24 thumbscrew and wing nut under the blast deflector.

Launch rods come in several different types. I called around town until I found a hardware store that carried stainless steel rods and bought my launch rods there. Most stores will carry steel rods in various sizes, but I have found that the stainless ones are typically only a dollar more than the other rods and most hardware stores will order them for you if they do not have them in stock.

El Cheapo launch pad Now that your El-Cheapo pad is complete, go launch some rockets into the sky!

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