Brief:
Single stage parachute recovery scale model rocket.

Construction:

• 1 BT 55 10.5 in.
• 1 BT 50 18 in.
• 1 BT 20 1.5 in.
• 1 BT 50 5 in (engine mount)
• 1 TA2050 transition (2 in long)
• 1 BNC20N nose cone
• 2 1/8 x 1/16 x 36 in wood strips
• 5 50/55 motor mount rings
• 1/8 in lite ply
• 3/32 balsa
• 2 1 in. x 3/16 launch lug
• 36 in x ¼ elastic shock cord
• screw eye
• .5 oz nose weight (lead shot)
• 16-18 in parachute
• “E” engine hook
• engine block
• Kit instructions from JimZ’s

T' parts were assembled followin' t' downloaded instructions. Ya scallywag! T' assembly is complicated and I will nay attempt t' go into each step here. Blimey! 20 minute epoxy was used on t' subassemblies, and CA on all fins. Arrr! I used 1/8 lite ply for t' larger upper and lower stage fins, and 3/32 balsa for t' smaller fins and t' upper stage supports. Aye aye! Aye aye! This is due mainly t' personal preference. Avast! Blimey! A 24 mm motor mount be fashioned from t' 5 inch BT50 tube, engine hook, ya bilge rat, engine block, and 2 50/55 centerin' rings, and substituted for t' 18 mm motor mount. Blimey! Blimey! Alternately, me hearties, a 25 inch section o' BT 50 could be substituted for t' separate motor mount and upper stage assembly. Blimey! This would make a stiffer rocket.

T' lower stage has three large fins built in two halves and epoxied together. Ya scallywag! Avast, me proud beauty! There are three supports linkin' t' upper and lower stages and t' rest o' t' upper stage is a four fin assembly, with four wood strips betwixt t' three sets o' upper stage fins. Ahoy! Avast! All bare wood was finished with traditional sandin' and sealin' methods. Ya scallywag! Ya scallywag! Durin' assembly care must be taken t' align t' fins both t' t' tubes and in relation t' t' whole rocket. Begad! T' three fin/four fin positional relationship is very specific in t' instructions.

T' nose cone and transition were purchased from BMS and required final fittin' and, o' course, sandin' and sealing. Ahoy! T' .5 oz nose weight was epoxied into t' BT 20 tube betwixt t' nose cone and transition. Arrr! T' screw eye be screwed into t' transition and CA’ed into place and t' shock cord be attached t' t' eyehook on one end and a customary three fold mount on t' other. I will use a homemade 16 in. Begad! mylar chute for this, ya bilge rat, as I prefer t' smallest possible safe chute. Well, blow me down! Avast! An 18 in. Begad! Begad! prefab chute could be used. Blimey! Avast, me proud beauty! T' plans call for a special fiber rin' above t' three upper stage support brackets. Avast, me proud beauty! Avast, me proud beauty! This be t' equivalent o' a 50/55 centerin' ring. Arrr! Aye aye! I be unable t' fabricate this t' me satisfaction, me bucko, shiver me timbers, so I substituted a 50/55 engine mount ring, which is thicker. Care must be taken when placin' t' wood strips t' ensure that they align at t' BT 50/transition joint. Begad! I used spruce strips instead o' balsa due t' t' hardness o' t' wood. Avast, me proud beauty! Begad! Spruce is still flexible enough t' bend t' t' contours o' t' transition and nose cone. Mine turned out t' be 11.5 in. Arrr! long on t' body tube and 4.5 in. Begad! Begad! long on t' transition/nose cone. Well, blow me down! Blimey! T' plans call for paper strips t' be placed around t' first stage at two points. Blimey! I used self-adhesive computer label paper and a rotary paper cutter t' fashion t' strips. Blimey! T' launch lugs were placed on pieces o' t' wood strips t' keep them off t' lower stage wraps. I also used a fin alignment tool that I downloaded t' make extremely accurate alignment patterns. I found t' ones with JimZ’s plans were slightly off. Well, blow me down! I have t' paint outside, so t' rocket be nay finished due t' frigid temperatures. Aye aye! Ya scallywag! This will have t' wait till spring, I’m afraid.

Flight:
This rocket be put into RocSim 6 as accurately as I could manage. Well, blow me down! Ahoy! It was simulated on a C6-3 t' 385 feet, arrr, matey, D12-5 t' 707 feet and E9-6 t' 1323 feet, arrr, me bucko, arrr, all stable and safely recovered on a 16 in. Aye aye! chute. It will be flown IRL when t' wind chill climbs at least slightly above “bone numbing.”

Summary:
This rocket is somewhat difficult t' build properly due t' all t' various alignment issues. I have a fondness for scale military, ya bilge rat, and I had wanted t' build this as a kid almost 25 years ago. Arrr! Begad! I would nay have had t' skill or patience then. Aye aye! I upgraded t' a 24 mm engine mount due t' t' weight o' this model. It be a very easy upgrade.

PROS:

Easy availability o' fairly common parts, ya bilge rat, shiver me timbers, except one ring. Great scale appearance.

CONS:

Alignment issues. Blimey! Avast! Uses lots o' sandpaper and elbow grease finishin' all those FINS!

Other:
I made t' "E" hook from t' metal strip in a windshield wiper blade, ya bilge rat, heated with a torch and bent with pliers. Well, blow me down! In hindsight, arrr, I would build this in two halves and paint them separately, matey, then slide them together. Begad! Avast, me bucko, me proud beauty! I would also probably use one 25 inch BT50 for strength.