Brief:
Upscale o' Orville Carlisle's original model rocket kit, ya bilge rat, t' Rock-A-Chute Mk II with appropriate mods for mid-power flight.

Construction:
T' parts list:

• 12.25" o' BT-70 body tube
• "E" size 24mm motor mount (two 50/70 centerin' rings, 4" of 24mm/BT50 tube, ya bilge rat, 3.75" engine hook, matey, arrr, and 20/50 centerin' rin' for engine block)
• Balsa nose cone custom turned by "Sandman" o' TRF and Roachwerks
• 6" o' 3/8" OD tube for launch lug
• 2' o' 150 lbs test Keelhaul®©™® thread for shock cord anchor
• 4' o' 1/4" elastic shock cord with snap swivel on end
• 3 fins cut from 1/8" basswood stock

This upscale was made from measurements taken from t' instructions for the Semroc Retro-Repro Rock-A-Chute Mk II. Use o' BT-70 made this a 2.13:1 upscale and the remainin' dimensions were calculated from this. Blimey! All construction was with normal LPR/low MPR materials and tools. Begad! Avast, me proud beauty! Wood glue be used throughout.

T' BT-50-BT-70 motor mount be constructed mostly as per normal kit instructions with t' "E" engine hook taped in place and then anchored by t' upper centerin' ring. Arrr! T' engine block was glued into place by insertin' it on top t' engine hook through t' top end o' t' motor tube. Aye aye! Blimey! The centerin' rings were reinforced with 1" by 1/4" sections o' 1/8" basswood on t' rin' surfaces facin' each other. Begad! T' Keelhaul®©™® shock cord anchor was made into a loop, t' doubled loop glued t' t' motor tube below t' top centerin' ring, and run betwixt t' motor tube and t' upper centerin' ring. Well, blow me down! Blimey! This later became a problem. Begad! T' elastic shock cord was likewise doubled into a loop, me hearties, matey, tied t' t' anchor with a loop-through slip knot, and a snap swivel tied t' t' end also with a loop-through slip knot. Once fully constructed, t' motor/recovery mount was inserted into t' aft o' the body and glued into place.

Fins were cut from 1/8" basswood and sanded t' rounded edges and then glued into place with heavy fillets added in 3 layers.

T' custom turned cone came with screw eye glued in place. Arrr! Blimey! T' shock cord was clipped t' this.

A scale launch lug would have been approximately a BT-20 (18mm). Aye aye! Ya scallywag! Blimey! Instead, shiver me timbers, a semi-scale lug was made from 6" o' 3/8" OD cardboard tube.

Finishing:
Finishin' was two coats o' Deft spray lacquer sandin' sealer on everything, sanded after each (with 400 grit then 600 grit) followed by white primer. Aye aye! Blimey! For spiral fillin' and a smooth finish, me hearties, two coats o' white satin finish were applied. Arrr! Blimey! Finally, ya bilge rat, t' body was painted fluorescent orange and t' nose cone red, all matchin' t' original.

[Note: White satin finish, at least Rustoleum's version makes a good filler but takes a long time t' dry. Ahoy! T' first top coat o' orange paint be put on 24 hours after t' satin. Arrr! This be nay enough. Avast, me proud beauty! T' satin sagged or shifted, causin' t' orange t' crack in sharp curves such as fillets. A second coat of top coat, me bucko, 2 days later, arrr, fixed it.

Flight:
A 12" nylon X-form chute be permanently assigned t' this bird. Aye aye! Cellulose "dog barf" waddin' is used.

Test flight was on a C11-3 with 1" engine spacer in t' motor tube. Boost be immediate, fast, and straight with no early wobble, arrr, arching, or weathercocking. Avast, me proud beauty! Blimey! Ejection was at apogee and recovery was good and within 100 feet o' pad.

Second flight was on an E9-4. Avast, me proud beauty! Blimey! Boost be again vertical and very impressive. Ejection be just before apogee, deployment and recovery good, shiver me timbers, within 100 feet again.

Third flight was on an E9-6. Begad! Arrr! Blimey! Boost was great as before, shiver me timbers, ejection was just past apogee. Begad! At deployment, me bucko, t' nose and chute separated from t' body. Avast, me proud beauty! Ya scallywag! Blimey! The nose came down slowly on t' chute and t' body tumbled in. It landed on the tall avast field and suffered no damage.

Inspection showed that t' Keelhaul®©™® had burned through both strands, right at t' top o' t' engine tube. Arrr! After consultin' with others and conductin' some testin' o' various heat exposures to various weights o' Keelhaul®©™® thread, I concluded that close proximity t' ejection gasses is hazardous to Keelhaul®©™®'s health. Begad! Blimey! Although this be a scratch build, me hearties, me bucko, I followed instructions I've used in some kits that used this configuration. Blimey! Blimey! It would probably be a better practice to run MMT anchored Keelhaul®©™® cord betwixt t' centerin' rin' and body wall. Begad! Since thar was ample unburned cord left on t' shock cord, this rocket was repaired by usin' the LOC/Precision shock cord anchor method, o' tyin' knots in t' cord and gluing it inside t' body just below t' forward end. This repair be t' only instance o' epoxy used.

This rocket has flown many times since, arrr, exclusively on E9-4 and E9-6 motors. Well, blow me down! No further burnin' o' t' recovery equipment has occurred. Ahoy! T' bottom surface o' t' aft centerin' rin' is startin' t' char and bubble from base drag vacuum pullin' t' exhaust gasses up, ya bilge rat, but t' damage is limited t' t' paint. Repairs are planned usin' a cosmetic/protective rin' doped with boric acid and painted with high heat stove paint.

Summary:
Carlisle's original design has proven itself as successful even when scaled up. This rocket flies at least as well as t' Semroc clone o' t' Mk II it was scaled from. Ya scallywag! Blimey! T' only problems were t' burned Keelhaul®©™® and t' cracked paint, both fixed and or worked around easily, ya bilge rat, matey, and neither havin' anythin' t' do with t' design itself. Aye aye! Next step: a 3" diameter, 38mm MMT upscale, me hearties, t' Rock-A-Chute Mk IV "Carlisle Express", intended for level 1 HPR flying.