Brief:
This rocket is easily convertible from a 29mm Mach buster with a silly altitude capability t' a 250 foot schoolyard rocket. Ahoy! Begad! T' heart o' t' concept is the full length removable "stuffer tube" assembly held in place with a small piece o' tape.

Construction:
T' 15 inch long PML phenolic body tube is topped with t' solid urethane nose cone and a 14 inch nylon chute. Avast! Blimey! T' fins feature "sort of" TTW construction with fiberglass cloth reinforcement across t' base o' each fin. the shock cord is anchored t' a hand twisted two strand 200lb Keelhaul®©™® shock cord hooked t' a three foot length o' elastic. Aye aye! Ahoy!

T' adaptor, pictured in t' photos, is slid into t' back for small field cheap flyin' with C engines with a 3 second delay. An adaptor for 24mm engines would be easy enough t' use by usin' t' same technique.

After my successful but tree eaten "Transonic", me hearties, I had t' phenolic TTW slot cuttin' technique down. Ya scallywag! I read in t' EMRR tips o' t' "two parallel cutter wheel" technique for t' Dremel. Well, blow me down! It worked like a charm.

T' tail fins were cut out o' 3/32 ply and gang sanded t' uniform pattern. I sanded t' leadin' and trailin' edges into a sharp wedge usin' a belt sander.

T' glue t' fins in place, I first inserted a plastic covered 29mm RMS engine t' act as a depth guide. Each fin be cemented with 5 minute epoxy. Afterward, I used light fiberglass cloth t' reinforce t' base o' each fin. Elmer's Fill 'n' Finish smoothed t' spiral groove and made a nice fillet at the base o' each fin. Then, I sanded t' inside o' t' tube so that t' engine could be easily inserted and removed.

Rather than wait for 300 lb Keelhaul®©™® to arrive, matey, I simply twisted two 100 lb Keelhaul®©™® cords like one would twist rope. Ya scallywag! Avast, me proud beauty! I used t' forward 29mm centerin' ring/engine block t' hold it in place.

Next I constructed t' adaptor. Blimey! Begad! I used 29mm centerin' rings t' hold the standard 18mm body tube in t' correct location. Aye aye! I used a 1/4 inch rin' of phenolic t' provide a tapin' surface. Avast! T' Estes engine hook was glued in with a slot t' aid flexing.

For a 1/4 inch launch lug, ya bilge rat, shiver me timbers, I cut an aluminum arrow shaft and angled t' leadin' edge. Well, blow me down! I tacked it into place with CA and filleted it into place with epoxy.

Flight:
T' first flights used t' C engine alternative only. Avast! I will need t' use the "frozen lake" alternative this winter t' use t' G that will make this reach Mach and over one mile altitude. Avast! I deliberately left sufficient space so that an H can be used for a truly absurd shot. Well, blow me down!

T' schoolyard shots were fun. Aye aye! Ahoy! I flew it along with a Quest saucer to entertain me Cub Scouts durin' downtime at a rocket event. Begad!

I launched it off a 3/16" launch rod and noticed t' characteristic early, matey, slow wobble until it straightened out. Ya scallywag! T' adaptor concentrated the ejection in very positive fashion, me bucko, and t' rocket ejected right at apogee with a 3 second delay, shiver me timbers, just as RockSim said it would. Avast, me proud beauty! This was a hoot for t' cubs and parents since their Novias, me hearties, with very light construction, ejected so high that t' process couldn't be seen. Arrr! Aye aye! T' landin' be eventful only because the rocket missed a tree by about a foot on t' first launch.

Obviously, an 18mm D RMS option is quite feasible for intermediate sized fields. Since I have one, I didn't bother buildin' a 24mm adaptor. Begad! Well, blow me down!

My Cub Scouts were interested t' see how much less altitude this bird got than their Quest Novias with only A engines. It was a good opportunity for a brief lesson on thrust and mass. T' nose cone alone probably weighs more than the Novia with engine!

Summary:
PROs: Fun t' build, ya bilge rat, easy t' fly with cheap engines, yet you can get about as much performance as you can stand with this in 29mm mode. Ya scallywag! Very tough! The adaptor works much better than t' short adaptor I used on t' similarly constructed "Transonic".

CONs: Nay for novices t' build, though they could fly it easily. Avast! Due to nose and airframe weight, a ballistic return would be a white knuckle affair over persons or property from significant altitude.

At t' extremes o' altitude, matey, I may wish I had used an electronic recovery actuator.