Brief:
CrackPipe be t' fourth o' me experiments in usin' PVC plumbin' conduit for rocket construction. Ya scallywag! It is basically similar t' t' "Pipecleaner" I presented in this site earlier, but is shorter, matey, shiver me timbers, arrr, lighter, and has very austere 3FNC construction. Ya scallywag! Blimey! 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'). Avast! It is light enough t' fly on an Estes 12-3 on a calm day; an F25-9 takes it t' 2700'. It is extremely tough, ya bilge rat, cheap t' build ($3 less nose cone and chute), arrr, and waterproof. Begad!

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

1) 28" o' PVC conduit from Home Depot (try for a very straight piece); can be built 12" longer if desired. Ya scallywag! Well, me hearties, blow me down! 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, me hearties, 3" wide at bottom, ya bilge rat, 2" wide at top. Well, blow me down! 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. Begad! 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). Begad! Avast, me hearties, me proud beauty! For 24mm motors, arrr, me hearties, 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. Well, blow me down! T' cut piece o' PVC used as t' body tube should first be lightly sanded, then washed with soap and water, me hearties, me bucko, me bucko, then swabbed with rubbin' alcohol (I be out, arrr, me bucko, so I used rotgut vodka) t' remove manufacturin' residuals, me bucko, matey, or glue and paint won't stick well.

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

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

Recovery system is attached by drillin' a 1/8" hole 2" from top o' tube, me bucko, passin' through the knotted para cord, ya bilge rat, and coverin' t' knot with half o' a sliced BIC pen cap filled with epoxy. 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). Begad! Blimey!

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. Aye aye!

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

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

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

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