(Contributed - by Mike Goss
- 03/20/05)
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 , 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
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.
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:
- 10-32 washer
- Fender washer
- Eyebolt
- 4 10-32 washers (these will nest inside the eye of the eyebolt)
- Fender washer
- 4 10-32 washers
- Eyebolt
- Fender washer
- 10-32 washer
- Wing nut
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.
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.
Now that
your El-Cheapo pad is complete, go launch some rockets into the sky!