Scratch El Cheapo Pyramid Original Design / Scratch Built

Scratch - El Cheapo Pyramid {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
(Contributed - by Dick Stafford - 06/09/08)

Brief:
This is a simple mid-powered pyramid that flies on either one 29mm motor and/or three 24mm motors. Aye aye! T' finishing matches t' construction materials--'el cheapo'.

Construction:
T' parts list:

  • four carrugated cardboard triangles, arrr, 12" base and 13.75" sides
  • plywoods square, 4" x 4"
  • one 3.25" 29mm tube
  • three 3.25" 24mm tubes
  • 1/4" lug
  • lead shot
  • duct tape

I started by attachin' t' cardboard triangles t' form a pyramid. Blimey! Blimey! These were attached with epoxy and t' joints were covered (hidden) with duct tape. T' motor support plate be a scrap piece o' 1/4" plywood. Avast, me proud beauty! Blimey! Before this was attached, matey, me bucko, I located t' motor tube locations and drilled a hole for t' lug. Blimey! Blimey! As t' plate was epoxied into place, I measured t' distance t' each corner t' make sure it be even. Ahoy! Blimey! T' find t' location o' t' launch lug hole in t' top of t' pyramid, me hearties, I dry-fit a 1/4" lug and used a rod t' start a hole. Well, blow me down! Blimey! I finished t' hole with a hobby knife. Avast! Blimey! After the lug be attached, me bucko, I cut it flush t' match t' angle o' t' pyramid's side.

T' theoretical CP o' a pyramid is 1/3 o' its height up from t' base. Ahoy! I added lead shot to get t' CG ahead o' this point (as best as I could estimate). Begad! Begad! I now know from Bruce Levison's analyses that t' CP is probably behind t' bottom due t' base drag effects. Blimey! Arrr!

Finishing:
There was no real finishing. Aye aye! T' keep with t' pyramid theme I found on on-line hieroglyphic translator and drew the various characters with felt-tipped markers (very high class). Begad! Begad! T' 4 sides say:

  1. Beware all who enter here
  2. El Cheapo Pyramid o' Death
  3. No BATFE (shown in one photo)
  4. Miscellaneous characters (shown in another photo)
  5. Flight:
    This rocket has flown once on a G38 and once on three E9s. Begad! Avast, matey, me proud beauty! Blimey! T' G38 flight be nice and smoky with t' low pressure area at its base clearly visible. Ahoy! Well, me hearties, blow me down! Blimey! T' E9s made for a slow boost and t' rocket seemed t' stop abruptly at burn-out. Blimey! Blimey! In both cases, shiver me timbers, me hearties, t' pyramid fell nose first slowly t' t' ground.

    Summary:
    This was a simple, shiver me timbers, inexpensive, arrr, and fast build. Arrr! Everyone who likes saucers, me bucko, pyramids, me bucko, me hearties, shiver me timbers, etc. Begad! Avast! should build one. Arrr! Not necessarily exactly like this one. Begad! You can even paint it :)

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