Clone - Nike Ajax {Scratch} Clone

Contributed by Robert Beckey

Manufacturer: Clone

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

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

Flight:
This rocket was put into RocSim 6 as accurately as I could manage. Blimey! Ya scallywag! It was simulated on a C6-3 t' 385 feet, D12-5 t' 707 feet and E9-6 t' 1323 feet, arrr, me bucko, all stable and safely recovered on a 16 in. Arrr! Begad! chute. Begad! Well, blow me down! 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. Aye aye! I have a fondness for scale military, and I had wanted t' build this as a kid almost 25 years ago. Aye aye! I would nay have had t' skill or patience then. I upgraded t' a 24 mm engine mount due t' t' weight o' this model. Avast, me proud beauty! Blimey! It be a very easy upgrade.

PROS:

Easy availability o' fairly common parts, except one ring. Begad! Arrr! Blimey! Great scale appearance.

CONS:

Alignment issues. 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, me hearties, heated with a torch and bent with pliers. In hindsight, me hearties, shiver me timbers, I would build this in two halves and paint them separately, then slide them together. I would also probably use one 25 inch BT50 for strength.

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