Scratch DIY Launch Pad

Scratch - DIY Launch Pad {Scratch}

Contributed by Geof Givens

Manufacturer: Scratch

(Scratch) DIY RailpadBrief:
This is a brief report on a do-it-yourself rail and rod launch pad I built. There are some good plans and information at EMRR and TRF, but I still had some questions and doubts when I began the project because I'm not very mechanically inclined. The first photo shows the final result, which I am quite happy with. On the rail is my Binder Design Thug (in progress) and on the adjacent Estes rod is "2 Fat" (see review here).

Construction:
Here are the parts:

  • 15 feet 1.25" PVC
  • 2.5 feet 1" PVC
  • 1 foot 1/2" galvanized, threaded "nipple" (pipe)
  • 4 #10 fine threaded bolts, 1.25" long
  • PVC purple primer and cement
  • 1 PVC adaptor piece, threaded .5" on one side and unthreaded 1" on other
  • 1.25" PVC parts: 1 cross, 3 tees, 4 45-degree elbows
  • 1 #10 wing bolt .5" long
  • 6 feet of 1010 rail
  • 5 #10 economy nuts (part #3276)

Tools required:

  • Power drill with 3/16" bit for metal drilling
  • tin snips
  • large tin can (e.g. coffee)
  • masking tape
  • any saw that cuts PVC
  • some washers or larger-than-#10 sized nuts to serve as fat washers
  • wood file
  • standard Estes launch pad and rod(s)

(Scratch) DIY Railpad

The rail attaches to the nipple via 3 bolts and specialized (#3276) nuts. The bottom end of the nipple screws into the adaptor. A suitable length (at least one foot) of 1" PVC cements to the other end of the adaptor. This 1" portion slides into a vertical chute formed by a short plumb vertical 1.25" pipe, then the cross, then a suitable length (enough to just touch the ground) of plumb vertical 1.25" pipe. This vertical portion prevents rail wobble and is also a major weight-bearing support for the pad assembly. A second detail photo shows the pad structure without the rail assembly.

Here's a few more minor points: You can wrap a little masking tape about the 1" rail mount to provide a snug but sliding fit. Mark and quickly file notches in the interior of the unused tee so a standard Estes rod mount will slide in tightly. Glue the elbows to the main pad assembly but don't glue the straight legs. This keeps them removable for transport. Cut, bend, and mount a tin blast shield with one of the remaining specialty nuts and wing bolt. [Note: the blast shield is removable and can be slid on the rail from the bottom.] Use the last specialty nut, a bolt, and some nuts/washers to create a stop above the blast shield, upon which the rocket will rest.

(Scratch) DIY Railpad

Summary:
Here were my worries going into the project. I'm writing this review to encourage other skeptics to give it a shot!

Q: Isn't it beyond the capabilities of a non-mechanical person with limited garage tools?

A: No! I have only a very basic power jigsaw and power drill. You might need to get some PVC primer and cement and buy the metal drill bit at Home Depot for a few bucks. I assembled it in a couple hours and I'm no rocket scientist.

Q: If you add up all the costs isn't it about the same as buying a manufactured one?

A: I don't think so. Depending on what you already have in your garage, the whole deal might cost only $40-50. Blacksky's basic system costs $115 + shipping and you get only 4 feet of rail with no auxiliary Estes rod mount.

Q: Is 8020.net's 1010 rail really the right thing? It can't be that easy!

A: Yes, it is. I'm using buttons from railbuttons.com. See that site for more info about compatibility of various buttons and rails.

Q: Can I really drill those holes in galvanized pipe?

A: Yes with a bit for drilling metal. Use a nail set or piercing tool to tap a guidance nick in the pipe before drilling the bolt holes. Make sure you buy galvanized pipe and not the black metal kind.

Q: Does 1.25" PVC really provide a sufficiently strong, stable platform?

A: Yes it seems to, but I'm not sure that 1" would. The main source of wobbliness seems to be related to how you connect the rail assembly to the pad, not pad instability itself. My slip-in system seems to provide a lot of support at the connection point to avoid stressing the pad, and it does an adequate job of preventing the rail from wobbling too much. You can reduce wobble further by increasing the snugness of the fit between the rail assembly and the pad, either with extra masking tape wraps or outright cement. But I prefer it to disassemble and be easily portable.

Q: Will I attract a lot of cute women (or guys) if I stand next to it?

A: I'm sure you will. It worked on my wife, although I'm surprised she got a sharp photo because she was laughing so hard.

Comments:

avatar
Rick Reid (January 6, 2015)

a great pvc pad there, I studied your's and a few others to build mine. I've got the lower part pretty much worked out, still need to get it all glued together.

here what I've got so far:

avatar
Rick Reid (February 11, 2019)

filled the legs with sand then capped them with some silicone, then painted the whole thing red and highlighted the legs with black & yellow spiral stripes


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