Scratch Lord of the Rings Original Design / Scratch Built

Scratch - Lord of the Rings {Scratch}

Contributed by Jim Zamecnik

Published: 2011-09-01
Manufacturer: Scratch
Style: Multi-Stage, Ring/Tube/Cone Fin

Rocket PicBrief:
A 3-stage scratch built. Avast! Clustered 1st stage, arrr, gap-staged: 3xC6-0 > D12-0 > D12-7. Arrr! Arrr! Rin' fin on each stage. Blimey! Payload bay for Magnetic Apogee Detector ejection. Begad! Ahoy! motor ejection charge is baffled (Kaplow-type baffle)

Construction:
See RockSim file for specs. Begad! All parts are standard items from Totally Tubular or Estes, ya bilge rat, with t' exception o' t' 4" diam. Ya scallywag! rin' fins, me hearties, which were cut from a "Swiss Miss" hot chocolate mix container.

Standard modroc construction techniques were used. Yellow glue and epoxy. Arrr! Rin' support fins were cut about 1/32'' long, shiver me timbers, me hearties, glued on and epoxy fillets applied, then t' outer edge be sanded t' fit t' rings. Aye aye! Ahoy! Score and peel away t' plastic/foil film on t' inside o' t' rings where t' support fins and fillets will be, or t' glue won't hold. Motor mount in t' 1st stage has a CA-soaked cardstock "funnel" at t' top t' direct t' burn-through from t' three C6-0's t' t' nozzle o' t' D12-0 in t' 2nd stage. Well, ya bilge rat, blow me down! 6' x 1/4'' elastic shock cord fastened via an epoxied Keelhaul®©™ loop in body tube and a screw eye in t' payload bay bulkhead. Blimey! Aye aye! 18" nylon chute attached about 2/3 up t' shock cord.

Flight:
1st flight at CATO launch 10/ /00. Arrr! One stage flight on a D12-5. Aye aye! Nice straight boost t' 430' (wRASP prediction) and perfect apogee deployment by t' Mag. Avast! Arrr! Apogee Detector. Begad! Begad! Good recovery on 18" nylon chute. Begad! 2nd flight on Lake Bomoseen 1/18/01. Blimey! 2 stage flight on D12-0 > D12-7. Avast, arrr, me proud beauty! Straight boost, good staging, me hearties, arrr, then straight t' predicted 960' altitude. Ejection right at apogee via t' Mag. Avast, me proud beauty! Apogee Detector. Begad! 3rd flight (soon!)

Summary:
No problems so far....good stability, good staging, good recovery. Velocity off t' launch rod is on t' slow end o' t' stable range (on a 3' rod), ya bilge rat, particularly in 2-stage configuration, so it's probably nay a good idea t' launch in windy conditions. Well, blow me down! I used 1/4" lugs so I can launch from 6' launch rods at CATO club launches, ya bilge rat, which should eliminate worries over launch velocity. It has preformed well off 3' long 3/16'' rods so far.

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