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

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, pencil, hobby knife, me hearties, ruler, me bucko, scotch tape, shiver me timbers, sandpaper, 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, me hearties, 3M MicroPore tape (first aid fabric tape) or maskin' tape, used t' strengthen t' leadin' edges o' all win' and tail surfaces. Blimey! Ahoy! Estes Tube Markin' Guide or VCP software t' make fin marking guides.

I would rate this build as easy t' intermediate. These instructions expect some basic knowledge o' rocketry, like how t' mark tubes, cut tubes, assemble engine mounts, etc. T' toughest part is gettin' everythin' lined up right so the glider separates easily from t' booster, yet is held securely during boost. Ahoy! 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. This will be t' upper half of the completed booster. Well, blow me down! If you've got t' nosecone socket, shiver me timbers, you can glue this in place as well, but be sure t' use glue compatible with plastic such as epoxy, polyurethane glue, or plastic cement. Begad! Once t' glue has dried, insert this tube into t' remainin' 6" piece o' BT-20. Begad! Avast!
2. Sand down your body tubes with some medium grit sandpaper. Avast, me proud beauty! Aye aye! 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. Blimey! Well, blow me down! I used t' Estes tube markin' guides t' do this. That makes it really easy t' do. If you don't have t' markin' guides, matey, you can download t' VCP program and create markin' guides. Well, blow me down! Ahoy! 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. Begad! Blimey! Run t' lines the whole length o' t' tube. Begad! Blimey! Two o' these lines will be used t' align fins and the remainin' line will be used t' align t' lower glider mount. Begad! Blimey! 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. Arrr! 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. Blimey! Ahoy! Blimey! Extend these lines from halfway up t' lower body tube t' t' end o' t' upper body tube. Arrr! Blimey!
6. Next assemble t' engine mount usin' t' adapter rings, BT-5, engine hook, and 13mm engine block. Arrr! Aye aye! Glue t' completed assembly into t' lower 6" section o' t' body tube. Begad! 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. Avast, me proud beauty! You may use any fin design you desire. Blimey! Just don't make them very large. Blimey! I used fins that measure 1.5" along the leadin' edge and 1" along t' root edge. Avast! Fin shape should nay matter much but you may want t' round off t' leadin' edge with sandpaper. Ahoy! 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. Make these by cuttin' ten pieces o' 1/16" balsa that measure 3/16" x 1/4". Begad! Glue these together sandwich-style in pairs. Well, blow me down! When you're done, shiver me timbers, you should have 5 small balsa blocks.
9. Cut three 3/4" lengths o' toothpick or 1/8" dowel stock. These pieces will slide into launch lugs and hold t' glider onto t' booster. 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, 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. Well, blow me down! 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.
12. Now you need t' glue on t' win' supports. Begad! 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. Aye aye! Aye aye! 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! Well, me bucko, blow me down! This makes t' glider mounts a lot stronger and less likely t' break off on landing. Begad! Ahoy! My upper glider mounts broke off while I was swin' testing, shiver me timbers, me bucko, so I made t' repair with CA at that point.
14. Attach your launch lug. Avast, me proud beauty! 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. Aye aye! Avast! 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. Avast! Blimey! Begad! Blimey! You may need t' wrap some scotch tape around the nosecone shoulder. Begad! Blimey! Do nay glue t' nosecone into t' body tube. 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. Arrr! Blimey! T' glider instructions say t' place t' open clip at t' front o' t' glider and the closed clip at t' rear. Blimey! I reversed this so that t' open clip is at t' rear and t' closed clip is at t' front. Avast, me proud beauty! Avast, me proud beauty! Blimey! T' wings are more securely held in place durin' flight with this arrangement. Begad! Ya scallywag! Blimey!
2. Glue t' cockpit piece, t' rudder, me hearties, and t' horizontal tail section t' the body o' t' glider with yellow glue. Well, blow me down! I also coated t' rudder and cockpit with yellow glue t' add strength. Begad! Ahoy!
3. I marked t' wings and glued on t' launch lugs that hold t' glider t' the mounts on t' booster. Avast, me proud beauty! 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. Well, arrr, blow me down! 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. Ahoy! It should nay matter which side (left or right) you attach it to. Avast! Avast!
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, me proud beauty! Begad! Blimey! Coat all win' leadin' edges with dope, maskin' tape, MicroPore tape, shiver me timbers, or scotch tape. Well, blow me down! Ahoy! Blimey! Yellow glue may warp t' balsa, so proceed with caution if you want t' try yellow glue. Ahoy! I used MicroPore tape and it seemed to work fairly well.
6. (Optional) I fitted t' glider with one rubber band instead o' t' two that are provided with t' glider. Begad! T' glider's wings are folded outward by the tension o' t' rubber band. One rubber band creates more tension and causes the wings t' unfold more quickly. Blimey! Aye aye! Blimey!

Make sure you test fly your glider after makin' these modifications. You should nay need t' trim t' glider at all because it is already well-trimmed by design. Aye aye! Ahoy! 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. Aye aye! Aye aye! 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. Blimey! Place a few sheets o' waddin' into t' booster, me bucko, pack the streamer and shock cord in, mount t' glider t' t' booster usin' t' glider mounts, me bucko, and insert a new A10-3T engine into t' engine mount. Balance the rocket booster on a ruler t' find t' CG. If t' CG is behind t' trailin' edge of t' glider's wings, me bucko, ya bilge rat, matey, 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. Well, blow me down! Begad! 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. Begad! You might want t' swin' test the glider-booster assembly t' ensure stable flight. Aye aye! 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. Thanks t' other club members for t' comments. Arrr! Begad! T' flights were maybe an 8 on a scale o' 1 t' 10. Blimey! Waddin' is required. Well, blow me down! 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 be just about perfect. T' booster fired up and launched, tiltin' slightly t' one side. T' flight went a bit squirrelly right before burnout. Arrr! Blimey! T' ejection charge fired, everythin' separated smoothly, t' booster fell t' earth, matey, shiver me timbers, and t' glider descended in a really tight circle. Begad! Blimey! Arrr! Blimey! Apart from the funky boost, everythin' was picture perfect! Blimey! I be impressed.

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

Summary:
This be a great experience for me bein' me first attempt at boost glider launchin' so I really cannot complain. Arrr! It actually got quite good air time for not goin' as high as I had hoped. Ahoy! I am now workin' on a BT-50 based booster for the same glider under A engine power. Ya scallywag! I would say this project is a good exercise in scratch building, modification, ya bilge rat, 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. Mildly challengin' construction.