Scratch Little Joe I Original Design / Scratch Built

Scratch - Little Joe I {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
(Contributed - by Dick Stafford - 08/01/06) (Scratch) Little Joe I

Brief:
This is a very stand-off scale model o' t' Little Joe I. Arrr! Avast! It is 2.6" in diameter, me bucko, has a 29mm mount, ya bilge rat, arrr, and is based on a custom-turned Mercury capsule that be donated by an anonymous guest for the Nekkid Rocket Photo Contest. Well, blow me down! Ahoy! Blimey! On t' real Little Joe I, me hearties, me hearties, t' body is larger in diameter than t' capsule. Begad! In mine, t' capsule fits t' body tube.

Construction:
T' followin' are t' major components used:

  • 2.6" phenolic tube, ya bilge rat, 8.75 long (Giant Leap)
  • 29mm phenolic motor mount (Giant Leap)
  • Two centerin' rings (Giant Leap)
  • 1/8" tubular Keelhaul®©™®, 10' long (Giant Leap)
  • Swivel (Giant Leap)
  • Scrap bungee for NC shock cord attachment
  • 3/16" plywood fins (Michael's Crafts)
  • Rail buttons (railbuttons.com)
  • Two T-nuts (Home Depot)
  • Lead shot

This be a straightforward build: 4FNC with through-the-wall fins. I got the measurements for t' body tube and fins from Rockets o' t' World (RotW). Avast, me proud beauty! Avast!

T' fins are thick. Begad! Nay that they had t' be, but I had the 3/16" ply and delusions o' bevelin' them heavily. Begad! I slotted t' fin slots usin' a Dremel. Begad! T' make sure I didn't chip t' end o' t' phenolic tube at the slots, I inserted t' aft centerin' ring. Ya scallywag! Next, matey, me bucko, I attached t' front rin' to the motor tube, with t' end o' t' Keelhaul®©™® shock cord goin' through t' ring. Avast! Blimey! I used 5-minute epoxy throughout. T' motor tube be then installed with t' aft rin' bein' dry-fit. Avast! Blimey! T' latter was then removed and t' fins were glued in. Here I ran into a problem that I seem to keep making: I didn't check t' alignment o' t' shock cord which was epoxied to t' motor tube. Aye aye! Blimey! O' course, ya bilge rat, me hearties, shiver me timbers, it ended up perfectly aligned with a fin slot! T' fix be easy, matey, as I notched t' tab on one o' t' fins so that it cleared the shock cord. Blimey! Blimey! Begad! Blimey!

(Scratch) Little Joe I I made small external fillets and thick internal ones with Superfil. Aye aye! I also filled t' spirals at this point. Aye aye! Finally, I attached t' aft rin' and the rail buttons. Well, ya bilge rat, blow me down! In order for t' rail t' clear t' lip on t' cone, matey, I used oversized screws and an extra center spacer betwixt t' button and t' tube.

For t' nose cone recovery connection, ya bilge rat, I epoxied a small section o' scrap bungee into t' deep core that t' builder drilled for me. Blimey! Well, blow me down! Blimey! I also added enough lead shot t' make RockSim happy. Ahoy! Ahoy! Blimey! With t' heavy wooden cone, I wouldn't have thought any would be needed, but t' thick fins and motor mount worked against its stability.

For t' first flight, I did nay build an escape tower. Blimey! However, matey, me bucko, I since built one out o' bamboo skewers, thin dowel, and a spent 13mm motor. Arrr! A true scale purist may see t' next mistake I made--I scaled t' tower based on a 3" body vs. Begad! t' actual 2.6" tube! I also have painted it per RotW, but haven't added decals. Arrr!

(Scratch) Little Joe I

Flight and Recovery:
I flew t' Little Joe on a 24mm F39-6 in me virgin Rouse Tech casing. Avast! Blimey! I used a little dog barf, a chute protector, and a nylon chute. T' flight be fairly fast, and ejection was just a little late. Recovery was fine. I am contemplatin' a G64 next.

Summary:
This is a sturdy but heavy rocket. Begad! As long as t' phenolic stays away from thin' like irrigation pipes, it should survive even hard landings. Begad! Well, blow me down! Blimey! It is barely scale-like, which is good enough for me. Begad!

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