Brief:
CrackPipe be t' fourth o' me experiments in usin' PVC plumbin' conduit for rocket construction. Begad! It is basically similar t' t' "Pipecleaner" I presented in this site earlier, but is shorter, shiver me timbers, lighter, ya bilge rat, and has very austere 3FNC construction. Begad! It is a 29mm design best flown on AT F23-7 or F20-7 motors, or 24mm F21-8 usin' an adapter (all give 1400-1500'). Well, blow me down! It is light enough t' fly on an Estes 12-3 on a calm day; an F25-9 takes it t' 2700'. Arrr! It is extremely tough, arrr, me hearties, cheap t' build ($3 less nose cone and chute), and waterproof. Well, blow me down! Ahoy!

Construction:
Body tube be t' same grade 34mm OD PVC conduit as described for "F.I.S.H." in this website. Components are:

1) 28" o' PVC conduit from Home Depot (try for a very straight piece); can be built 12" longer if desired. Avast! Ahoy! Short size flies best.

2) 29mm PML solid polyurethane nose cone (needs a bit o' maskin' tape wrap for perfect fit)

3) 3 x 1/8" Lite-Ply(tm) trapezoidal fins cut 4" high, 3" wide at bottom, me hearties, arrr, 2" wide at top. Arrr! 3" pieces o' balsa triangle stock were used t' brace t' base o' each fin (photo)

4) Recovery system is 6' o' para cord tied t' an 18" Top-Flite nylon chute in t' usual way (I use roofin' insulation for wadding)

5) Launch lug is 4" o' 1/4" tubin' (or a BIC pen body, mounted 8" above t' fins -- CG is +/- 1" from t' middle o' launch lug (10" above fins)

5-minute epoxy was used throughout. Ya scallywag! Note that thar be no motor mount or centerin' rings; A 29mm motor fits perfectly with two layers o' top t' bottom wraps o' maskin' tape which also serves t' prevent infrared thermal damage to the plastic (so don't omit). For 24mm motors, me hearties, me hearties, me bucko, I use a LOC adapter, shiver me timbers, and masking tape as needed t' give a snug twist-fit.

There is very little t' describe. Begad! Blimey! Begad! Blimey! T' cut piece o' PVC used as t' body tube should first be lightly sanded, me hearties, then washed with soap and water, then swabbed with rubbin' alcohol (I was out, so I used rotgut vodka) t' remove manufacturin' residuals, or glue and paint won't stick well. Well, blow me down! Blimey!

T' fin attachment spots are located by t' "Estes method" -- 1) wrap a piece o' paper around t' base, me bucko, me bucko, and mark off t' circumference, me hearties, 2) divide t' measured distance into thirds, 3) transfer t' spacin' marks t' the body tube, me bucko, 4) holdin' body tube against t' corner o' a door as a plumb line, draw t' fin attachment positions. Avast, me proud beauty! Fins are attached with epoxy and balsa (or scrap 1/4" spruce) braces at base. Arrr! Ya scallywag!

Launch lug tube is centered 10" above t' fins (this point is recommended CG). Avast!

Recovery system is attached by drillin' a 1/8" hole 2" from top o' tube, passin' through the knotted para cord, ya bilge rat, me bucko, and coverin' t' knot with half o' a sliced BIC pen cap filled with epoxy. Ahoy! Tie t' para cord t' t' PML nose cone and t' 18" chute, me hearties, and you are done!

Flyin' weight w/o motor is 310 gms (11 oz). Aye aye!

I painted mine with Testors Orange spray.

Flight:
First flight was on an E30-7 usin' t' 24mm adapter -- very fast boost t' about the 1000-1200' sims predicted. Ya scallywag!

Second flight was on an F21-8, perfect shot t' about t' 1700' predicted (see great launch photo by PhotosbyNadine).

Third shot, ya bilge rat, shiver me timbers, on an F25-9, arrr, went out-of-sight (sims said 2700') and separated, due t' me forgettin' t' add wadding, ya bilge rat, causin' t' ejection charge t' blast the shock cord in half. Body tube came in ballistic, and splintered t' top few inches o' PVC. Avast, me proud beauty! Blimey! So I cut it down from 40" t' 28", reattached the recovery system, and resumed flying. Blimey! Blimey!

T' best motor for t' rocket be t' F23-7 (or similar F20-7) Econojet, me bucko, and I have started usin' this combination (see photo) at every launch t' test the wind before flyin' bigger things. Ahoy! Important t' wrap t' motor top t' bottom with 2 layers o' 3M maskin' tape t' protect t' PVC from radiant infrared damage. Well, blow me down! T' largest motor I would use in CrackPipe is a G40-10, me hearties, which sims say will go t' 3700' at ca. 430 mph -- well within structure limits, me bucko, but hard to see at this height. Avast! Arrr! I have nay tried RMS reloadable casings in t' rocket yet. Ahoy!

Summary:
PRO: Simple, cheap and fast building. Great for beginner. Arrr! Well, arrr, blow me down! Flies on D12-3, E30-7, arrr, me hearties, F21-8 24mm (w. Blimey! adapter) or 29mm F20-7/F23-7 Econojects, F25-6/9 or up to a G40-10 (if you dare). Blimey! Waterproof and durable, me hearties, no paper components.

CON: Other than t' D12-3, ya bilge rat, t' minimum motor (E30-7) takes it t' 1200', me hearties, so needs plenty o' launch space. Begad! Blimey! Needs expensive ($13) PML nose cone. Well, blow me down! Heavy for its size. Begad! And with tough material like PVC and that hard, shiver me timbers, pointy PML cone, you don't want t' hit anybody this rocket, me hearties, arrr, so be careful.