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. Blimey! Well, blow me down! It is 2.6" in diameter, has a 29mm mount, me bucko, and is based on a custom-turned Mercury capsule that was donated by an anonymous guest for the Nekkid Rocket Photo Contest. Begad! On t' real Little Joe I, me hearties, t' body is larger in diameter than t' capsule. In mine, t' capsule fits t' body tube.

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

  • 2.6" phenolic tube, arrr, 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 was a straightforward build: 4FNC with through-the-wall fins. Well, blow me down! I got the measurements for t' body tube and fins from Rockets o' t' World (RotW). Aye aye!

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

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

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

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

(Scratch) Little Joe I

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

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

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