This two-stager always gets attention when I brin' it out at our South Florida joint NAR/TRA monthly launch. Begad! Blimey! Everyone loves Reddy-Kilowatt fins! Blimey!

CAT-Scratch Rocketry
Chain Lightnin' is one o' me series o' "CAT-Scratch" rockets, where CAT stands for Collect Any Trash. Ya scallywag! Blimey! CAT-Scratch rockets avoid t' use o' any commercial rocketry items (barrin' t' engine). (You, on t' other hand, matey, me hearties, are free t' build your own Chain Lightnin' with standard tubes and cones.)

Two Stages: Double T' Fun
T' booster stage accepts a 24mm engine, me hearties, a D12-0. Avast, shiver me timbers, me proud beauty! When this engine completes its thrust phase, t' ejection charge occurs without delay. Ya scallywag! This charge ignites the D12-7 or D12-5 in t' upper stage. Ya scallywag! Ahoy! Two 3/16" vent holes near t' top of t' booster prevent gases from separatin' t' stages before upper ignition. T' booster tumbles t' recovery. Avast, me proud beauty!

General Construction
T' 24" body o' t' upper stage and t' 4" body o' t' booster were cut from t' same 2"-diameter Christmas wrappin' paper tube. Begad! Aye aye! Blimey! (I believe Estes BT-70 tubin' would be close enough as well.) T' upper stage motor mount is a long "stuffer tube" t' minimize t' pressurization space for recovery ejection. I rolled a bit o' cardboard t' make a coupler that I glued into t' top o' t' booster stage. Ya scallywag! I used yellow carpenter's glue throughout this project. Blimey! Blimey!

Motor Mounts
As a diehard CAT-scratcher, I rolled me own 24mm engine tubes. Avast, me proud beauty! Blimey! I used manila folder cardboard, placed a D12 in t' center, and rolled t' about two thicknesses, securin' t' final edge with plain old maskin' tape. Avast, me proud beauty! Blimey! (T' initial edge was held with a piece o' tape and some yellow glue). Ahoy! Blimey! Tacky? I've found that after cuttin' and applyin' sturdy cardboard centerin' rings, such an engine mount is plenty strong. I bent me own engine hooks as well, ya bilge rat, from 1/32" steel "piano wire" from t' hobby store. Feel free t' use commercial tubing, me hearties, rings and hooks.

Styrofoam Nose Cone
Craft stores like Michael's and places like Wal-Mart offer styrofoam cones. Avast, me proud beauty! Buy one with a diameter a bit larger than that o' t' body tube. Then carefully roll t' lower end o' t' cone against a table, crushin' it into a cylindrical shoulder o' about 1.5" length. Avast, me proud beauty! Fit-test it periodically as you roll; if you've gone too far (as I did), wrap t' shoulder with maskin' tape until it fits snugly into t' upper stage end. Ya scallywag!

How Do You Put An Eye-Hook Into Styrofoam?
T' eyehook for t' shock cord and parachute is a small piece o' clothes-hanger wire bent into an "8"-shape by needle-nose pliers. Avast! T' upper loop is pressed into t' bottom o' t' cone. Then a 1.75" straight piece o' wire is pressed laterally into t' side o' t' cone shoulder so that it intersects that upper loop. T' result: t' hook stays embedded in t' cone very securely.

Recovery System
Attached t' t' top o' t' stuffer tube is a 10" steel fishin' leader. Arrr! To this I tied a 36" piece o' 3/8"-wide flat elastic from the cloth-store as a shock cord. Avast, me proud beauty! T' other end goes t' t' eye-hook on t' nose cone. Avast, me proud beauty! Ahoy! I then cut a hexagonal piece o' bright yellow ripstop nylon, attached six notebook-paper hole-reinforcement circles t' t' corners, shiver me timbers, perforated the corners and tied on some kite strin' shroud lines. Ahoy! In typical fashion, shiver me timbers, I passed the three shroud loops through t' nose cone eye-hook. Ya scallywag! Arrr! (T' booster tumbles to recovery.)

Launch Loops
Instead o' standard launch lugs, arrr, I cut t' larger end o' a large paper-clip and bend it at a 45-degree angle. Arrr! This produces a "launch loop" which accepts a 1/4" launch rod. I epoxied two such launch loops t' t' upper stage, shiver me timbers, one near t' bottom and one about 11.5" from t' end. Avast, me proud beauty! Remember that the booster fins will be aligned in betwixt t' upper stage fins; align your launch loops so t' rod will nay hit any fins!

Those Cool Fins
T' fins are cut from 3/32" basswood from t' craft store. All it took was a razor-knife and some patience. Avast! Begad! These were surface-mounted t' t' two stages, three t' a stage, with yellow carpenter's glue. Avast, me proud beauty!

Finishin' Touches
I sprayed t' rocket fire-engine red and t' nose cone yellow, then dust-sprayed t' tips o' those glorious fins yellow. T' "Chain Lightning" logo be created with Sierra's PrintArtist software, arrr, matey, printed by an HP color inkjet printer onto an 8x11 sheet o' Avery sticky-backed label paper, cut out and affixed t' t' rocket. Well, blow me down!

How It Flies
You may have noticed that this rocket appears overstable. Aye aye! Avast! Blimey! Bingo! Blimey! Most multi-stagers are. T' dramatic thunderbolt fins result in sizable weathercocking. And what about damage t' those pointy things? Remarkably, me bucko, the fins have remained in great shape; basswood is tough. Arrr!

Final Notes
Make sure t' coupler betwixt t' booster and upper stage is nay too tight. Blimey! If you hold t' rocket upside-down by t' booster, shiver me timbers, arrr, t' upper stage should almost be tryin' t' come out. Aye aye! Ya scallywag! When you assemble t' two stages for flight, arrr, shiver me timbers, shiver me timbers, align the fins out o' kilter, nay in line with each other.

Here's T' Parts List Again

• Yellow carpenter's glue
• 2.0" diameter wrappin' paper tube by 4" long (booster)
• 2.0" diameter wrappin' paper tube by 24" long (second stage)
• 2" - 3" diameter styrofoam cone from Michaels or Wal-Mart
• 3" wide by 3/32" thick basswood from Michaels or hobby store
• Manila folder cardboard rolled into two 24mm motor mounts
• Additional cardboard for coupler, centerin' rings, engine blocks
• 1/32" piano wire for engine hooks
• Two paper-clips cut into 1/4" "launch loops"
• Clothes-hanger wire for nose cone eye-hook
• 10" steel fishin' leader for shock cord relief
• Ripstop nylon for parachute
• Kite strin' for shroud lines
• Six notebook paper hole reinforcement stickers for parachute
• Lightweight spackle t' fill t' nose cone
• Primer and paint