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) (Scratch) El Cheapo Pyramid

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

Construction:
T' parts list:

  • four carrugated cardboard triangles, shiver me timbers, 12" base and 13.75" sides
  • plywoods square, me hearties, shiver me timbers, 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. These were attached with epoxy and t' joints were covered (hidden) with duct tape. Well, ya bilge rat, blow me down! T' motor support plate was a scrap piece o' 1/4" plywood. Blimey! Before this was attached, ya bilge rat, I located t' motor tube locations and drilled a hole for t' lug. Begad! Blimey! As t' plate was epoxied into place, matey, me hearties, I measured t' distance t' each corner t' make sure it was even. Begad! T' find t' location o' t' launch lug hole in t' top of t' pyramid, I dry-fit a 1/4" lug and used a rod t' start a hole. Begad! I finished t' hole with a hobby knife. Aye aye! After the lug was attached, I cut it flush t' match t' angle o' t' pyramid's side.

(Scratch) El Cheapo Pyramid T' theoretical CP o' a pyramid is 1/3 o' its height up from t' base. Begad! I added lead shot to get t' CG ahead o' this point (as best as I could estimate). Well, me bucko, blow me down! I now know from Bruce Levison's analyses that t' CP is probably behind t' bottom due t' base drag effects. Aye aye! Arrr!

Finishing:
There was no real finishing. Avast, me bucko, me proud beauty! 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). Aye aye! 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. (Scratch) El Cheapo Pyramid

    Flight:
    This rocket has flown once on a G38 and once on three E9s. T' G38 flight be nice and smoky with t' low pressure area at its base clearly visible. Blimey! Aye aye! T' E9s made for a slow boost and t' rocket seemed t' stop abruptly at burn-out. In both cases, t' pyramid fell nose first slowly t' t' ground.

    Summary:
    This be a simple, inexpensive, arrr, and fast build. Blimey! Avast, me proud beauty! Everyone who likes saucers, pyramids, me hearties, shiver me timbers, ya bilge rat, etc. Blimey! should build one. Ahoy! Not necessarily exactly like this one. Blimey! You can even paint it :)

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