Brief:
Single stage boost glider that uses a modified Guillow's Foldin' Win' balsa glider.

Construction:
T' followin' parts list is for t' 13mm powered version:

• 1 Guillow's Foldin' Win' balsa glider
• 1 2.5" BT-5 tube (engine mount)
• 2 BT-5 t' BT-20 centerin' rings
• 1 engine hook
• 1 13mm engine block
• 1 6" long BT-20 tube
• 1 4" long BT-20 tube
• 1 BT-20 nose cone
• 1 BT-20 tube coupler
• 4 3/4" launch lugs
• 3 toothpicks or 1/8" dowel stock
• 1/16" balsa stock for fins and standoffs
• Several pinches o' clay for nose weight
• Standard Estes thin shock cord
• 18" streamer
• Glue, ya bilge rat, me hearties, pencil, shiver me timbers, hobby knife, ruler, scotch tape, sandpaper, me hearties, arrr, etc.
• (Optional) One nosecone "socket" with loop for attachin' shock cord t' BT-20 tube coupler and top half o' booster.
• (Suggested) Crystal Clear Scotch Tape, matey, arrr, 3M MicroPore tape (first aid fabric tape) or maskin' tape, me hearties, used t' strengthen t' leadin' edges o' all win' and tail surfaces. Aye aye! Begad! Estes Tube Markin' Guide or VCP software t' make fin marking guides.

I would rate this build as easy t' intermediate. Well, blow me down! These instructions expect some basic knowledge o' rocketry, me bucko, like how t' mark tubes, cut tubes, me bucko, matey, assemble engine mounts, me hearties, etc. Well, blow me down! T' toughest part is gettin' everythin' lined up right so the glider separates easily from t' booster, shiver me timbers, yet is held securely during boost. Avast, me proud beauty! This step should nay be too difficult if you follow these instructions.

Booster Assembly

1. T' best way t' start buildin' t' booster is t' glue t' BT-20 tube coupler into one end o' t' 4" long BT-20. Aye aye! This will be t' upper half of the completed booster. Ahoy! Avast, me bucko, me proud beauty! If you've got t' nosecone socket, me bucko, you can glue this in place as well, but be sure t' use glue compatible with plastic such as epoxy, polyurethane glue, arrr, or plastic cement. Once t' glue has dried, shiver me timbers, insert this tube into t' remainin' 6" piece o' BT-20. Arrr! Avast, me proud beauty!
2. Sand down your body tubes with some medium grit sandpaper. This will allow glue t' adhere better t' t' tubes.
3. T' next step is t' mark t' tubes for fins and standoffs/glider mounts. Well, blow me down! Begad! I used t' Estes tube markin' guides t' do this. Ahoy! That makes it really easy t' do. If you don't have t' markin' guides, you can download t' VCP program and create markin' guides. Avast! You will need one markin' guide for 3 fins and one markin' guide for 4 fins.
4. Mark t' lower body tube for three equally spaced fins. Arrr! Run t' lines the whole length o' t' tube. Arrr! Two o' these lines will be used t' align fins and the remainin' line will be used t' align t' lower glider mount. Well, me hearties, blow me down! I prefer t' mark two o' t' lines with a "F" for fins and t' remainin' one with a "M" for mount t' distinguish them later.
5. Mark t' upper body tube and t' upper portion o' t' lower body tube for the upper glider mounts and win' supports. Ya scallywag! Blimey! Ya scallywag! Blimey! Use your four fin markin' guide to mark t' tubes with two parallel lines, shiver me timbers, one on either side o' t' body tube. T' easiest way t' do this is t' align your markin' guide with the "M" line you made in t' last step and mark lines on either side of that line usin' t' markin' guide. Well, blow me down! Blimey! Aye aye! Blimey! Extend these lines from halfway up t' lower body tube t' t' end o' t' upper body tube. Ya scallywag! Blimey!
6. Next assemble t' engine mount usin' t' adapter rings, shiver me timbers, arrr, BT-5, shiver me timbers, matey, engine hook, and 13mm engine block. Ya scallywag! Glue t' completed assembly into t' lower 6" section o' t' body tube. Avast, me proud beauty! Line t' lower end o' t' mount up with t' body tube. Give t' engine mount some time t' dry.
7. Now you can glue on your fins. You may use any fin design you desire. Begad! Blimey! Just don't make them very large. Begad! I used fins that measure 1.5" along the leadin' edge and 1" along t' root edge. Begad! Fin shape should nay matter much but you may want t' round off t' leadin' edge with sandpaper. Glue your fins to t' lines you marked with an "F." Fillet t' fins once t' root edge joint has dried.
8. Create t' standoff blocks for t' glider mounts and win' supports. Avast! Make these by cuttin' ten pieces o' 1/16" balsa that measure 3/16" x 1/4". Begad! Well, ya bilge rat, blow me down! Glue these together sandwich-style in pairs. Ahoy! Ahoy! When you're done, you should have 5 small balsa blocks.
9. Cut three 3/4" lengths o' toothpick or 1/8" dowel stock. Begad! These pieces will slide into launch lugs and hold t' glider onto t' booster. Arrr! Glue the three toothpicks/dowels t' t' tops o' three o' t' small balsa blocks with one end o' t' dowel aligned with one end o' t' block.
10. Once your glider mounts have dried, matey, you can attach them t' your booster. T' top section o' t' booster will have two glider mounts attached t' it. Glue these pieces even with t' end o' t' upper BT-20 where t' tube coupler has been glued in. Begad! T' dowel rods should extend out past t' end o' t' BT-20 coupler
11. Glue t' lower glider mount t' t' lower section o' t' body tube along the line you marked with a "M." This mount should be lined up with the aft end o' t' body tube with t' dowel extendin' upward. Avast, me proud beauty!
12. Now you need t' glue on t' win' supports. Avast! These are glued onto t' lower half o' t' body tube along t' two parallel lines you extended from t' top half o' t' body tube. Arrr! T' win' supports are glued 3.5" from t' bottom end o' t' lower body tube.
13. One thin' you may want t' do t' strengthen your glider mounts and wing supports is t' saturate them with CA. Begad! This makes t' glider mounts a lot stronger and less likely t' break off on landing. Ahoy! My upper glider mounts broke off while I be swin' testing, ya bilge rat, so I made t' repair with CA at that point.
14. Attach your launch lug. This can be wherever you want but just make sure it doesn't interfere with any o' t' glider mounts.
15. Attach t' shock cord t' t' inside o' t' lower section o' t' booster with a standard tri-fold shock cord mount. Either tie t' other end t' the nosecone socket or glue into t' BT-20 tube coupler on t' top half o' the booster. Attach your streamer t' t' middle o' t' shock cord with tape.
16. T' final step in assemblin' t' booster is t' securely insert t' nosecone into t' top end o' t' booster. Aye aye! You may need t' wrap some scotch tape around the nosecone shoulder. Avast! Do nay glue t' nosecone into t' body tube. Arrr! You may need t' add clay weight t' it later (see CG Placement section below.) Just make sure it is a tight friction fit.

Glider Modifications

1. Reverse t' clips used t' hold t' wings onto t' body. Aye aye! T' glider instructions say t' place t' open clip at t' front o' t' glider and the closed clip at t' rear. Aye aye! Ahoy! I reversed this so that t' open clip is at t' rear and t' closed clip is at t' front. T' wings are more securely held in place durin' flight with this arrangement. Ahoy!
2. Glue t' cockpit piece, t' rudder, and t' horizontal tail section t' the body o' t' glider with yellow glue. Ahoy! I also coated t' rudder and cockpit with yellow glue t' add strength. Begad!
3. I marked t' wings and glued on t' launch lugs that hold t' glider t' the mounts on t' booster. T' launch lugs are glued t' t' undersides o' t' wings and are spaced 3 5/8" from t' tips o' t' glider's wings. Arrr! I glued the launch lugs with 1/8" o' t' lugs extendin' past t' leadin' edges o' the wings.
4. T' aft launch lug should be attached t' t' side o' t' rudder near the top edge. Arrr! It should nay matter which side (left or right) you attach it to.
5. (Optional) I would suggest this as it adds more strength t' t' glider's vulnerable win' surfaces. It is required if you want t' launch t' glider with more powerful engines. Avast! Coat all win' leadin' edges with dope, maskin' tape, MicroPore tape, ya bilge rat, or scotch tape. Yellow glue may warp t' balsa, so proceed with caution if you want t' try yellow glue. Avast, me proud beauty! Ya scallywag! I used MicroPore tape and it seemed to work fairly well. Aye aye!
6. (Optional) I fitted t' glider with one rubber band instead o' t' two that are provided with t' glider. T' glider's wings are folded outward by the tension o' t' rubber band. Aye aye! One rubber band creates more tension and causes the wings t' unfold more quickly. Arrr!

Make sure you test fly your glider after makin' these modifications. Avast! Blimey! You should nay need t' trim t' glider at all because it is already well-trimmed by design. Ya scallywag! Blimey! If you do need t' trim it, then you can tape some clay t' t' glider body under t' nose or under t' horizontal tail section. Avast! It should glide quite far when tossed gently.

CG Placement

You should now assemble t' glider/booster combo as it would be assembled durin' flight. Begad! Blimey! Place a few sheets o' waddin' into t' booster, pack the streamer and shock cord in, ya bilge rat, mount t' glider t' t' booster usin' t' glider mounts, and insert a new A10-3T engine into t' engine mount. Balance the rocket booster on a ruler t' find t' CG. Aye aye! Blimey! If t' CG is behind t' trailin' edge of t' glider's wings, you need t' add a pinch or two o' clay t' t' nosecone. T' CG should actually be exactly betwixt t' wings o' t' glider. Begad! Blimey! You can check this by tyin' some strin' t' t' booster tube with a slip knot and slide forward and backward t' find t' CG. Ahoy! Blimey! You might want t' swin' test the glider-booster assembly t' ensure stable flight. Press clay into end of nosecone with a dowel as necessary.

Flight and Recovery:
Both flights were on A10-3T's at t' Southern Arizona Rocketry Association's May 2005 launch. Ya scallywag! Blimey! Thanks t' other club members for t' comments. Arrr! Blimey! T' flights were maybe an 8 on a scale o' 1 t' 10. Arrr! Blimey! Waddin' is required. Begad! Blimey! T' booster should be prepped in t' same manner as you'd prep any other streamer recovery rocket. Mount t' glider t' t' booster body once you've put t' waddin' in and inserted most o' t' shock cord into t' body tube.

T' first launch was just about perfect. T' booster fired up and launched, tiltin' slightly t' one side. Begad! T' flight went a bit squirrelly right before burnout. Begad! Avast, me proud beauty! T' ejection charge fired, me bucko, shiver me timbers, everythin' separated smoothly, t' booster fell t' earth, ya bilge rat, and t' glider descended in a really tight circle. Aye aye! Apart from the funky boost, shiver me timbers, everythin' be picture perfect! I was impressed.

T' second flight was almost a repeat o' t' first flight. Well, blow me down! I don't think the boost went as high as t' first flight, me bucko, me hearties, but it went up and released the glider right on cue. Begad! T' glider once again circled tightly t' t' ground. I can't complain about either flight! Way better than I ever expected.

Summary:
This was a great experience for me bein' me first attempt at boost glider launchin' so I really cannot complain. Avast, me proud beauty! Ya scallywag! It actually got quite good air time for not goin' as high as I had hoped. Arrr! I am now workin' on a BT-50 based booster for the same glider under A engine power. Avast! I would say this project is a good exercise in scratch building, arrr, shiver me timbers, modification, me hearties, and boost glider launching.

PROs: A neither too easy nor too hard glider modification, and nay a bad first boost glider project for t' scratch builder.

CONs: It didn't go that high, which could be remedied by buildin' a more powerful booster. Avast! Mildly challengin' construction. Ahoy! Begad!