Scratch SynerJet Original Design / Scratch Built

Scratch - SynerJet {Scratch}

Contributed by Kathy Kippen

Manufacturer: Scratch
(Contributed - by Kathy Miller - 06/21/09) (Scratch) Synerjet

Brief:
This a scratch built spaceship rocket designed for t' 2009 Design-A-Spaceship contest. It is constructed o' 110lb cardstock and presentation board.

Construction:
T' parts include:

  • BT-50 for t' internal tube/motor mount
  • screw eye
  • presentation board for centerin' rings, fins, ya bilge rat, and bulkhead
  • ¼" elastic shock cord
  • 1" plastic streamer
  • 1/8" launch lug
  • 110lb cardstock
  • clay for nose weight
  • 1 BT-50 size centerin' ring
  • motor block for BT-50 tube
  • 1-½" long coupler t' fit into BT-50 tube (can make from BT-50 tube)

I first cut t' centerin' rings, bulkhead, and fins from t' presentation board. Begad! Next I cut t' BT-50 to 4-½". Well, blow me down! I used an online transition template t' print out t' templates for t' nose cone, body, arrr, shiver me timbers, and tail cone. For t' larger centerin' rings, matey, I used t' template printout from RockSim. For t' bulkhead, arrr, I just used one of t' 'holes' from a centerin' ring.

After printin' out t' templates on t' cardstock, I then carefully shaped t' nosecone and transition sections into cone shapes. After they dried, me bucko, I dry fit t' paper sections onto t' centerin' rings sandin' as necessary. Blimey!

Next, I glued t' motor block into t' tube usin' a spent 24mm motor t' push it into place leave ¼" t' 3/8" o' t' motor stickin' out. Ahoy! Begad! After that had set, shiver me timbers, I glued t' centerin' rings onto t' body tube: the smallest rin' ¼" below t' top o' t' tube, t' two larger tubes at 2-½" and 2-¾" from t' top o' t' tube and t' medium rin' flush with t' bottom o' t' tube.

After t' glue has dried, shiver me timbers, ya bilge rat, I carefully glued t' middle transition section t' t' top end o' t' tube makin' sure it is perfectly straight on t' top centerin' rin' and top middle centerin' ring. Avast! Blimey! Then I added t' transition t' the bottom again makin' sure t' piece was perfectly straight on t' lower middle rin' and bottommost ring. I let it thoroughly dry.

(Scratch) Synerjet(Scratch) Synerjet

T' finish t' nose cone, I glued t' coupler onto t' nose cone bein' careful t' get it straight. When it was dry, me bucko, I filled t' cone with clay leavin' a ¼" lip t' t' edge. Well, blow me down! Arrr! Glued t' bulkhead into t' coupler. Aye aye! When all was dry, I added t' screw eye for shock cord attachment.

As this is a tricky design, matey, I glued t' launch lug t' a fin makin' sure it was straight.

T' shock cord is mounted in t' Estes fashion with t' other end tied t' t' screw eye. T' streamer is tied on about 1/3 from t' nose cone.

Finishing:
Since I used color cardstock, I didn't really need t' paint anything. Begad! Blimey! I used a color highlighter marker t' paint the fins t' match t' cardstock.

Flight:
T' Synerjet flew on C11-3s for all three flights. Ahoy! T' first flight was unstable. Begad! For t' second flight, I used a spacer t' extend t' motor out t' back ½". This caused t' rocket t' be even more unstable. Aye aye! T' third flight was a recreation o' t' first.

Recovery:
Recovery for all flights was after t' rocket hit t' ground. Ya scallywag! Well, blow me down! Each landin' broke a forward fin off.

Summary:
I would say this is nay a good rocket design as it is too stubby t' be stable. Ahoy! Even tryin' t' upscale it in RockSim it was nay stable. Aye aye! Well, blow me down! It was a fun and interestin' build.

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