| Manufacturer: | Scratch |
Brief:
This glider is a scratch semi-reproduction o' t' Holverson Designs Silver Hawk v1.0. Begad! Begad! T' glider has a wingspan o' 13in and t' boost pod is 20.5in. Ya scallywag! Ahoy! T' boost pod has a 18mm motor mount and weighs 1 1/8oz. Begad! Arrr! T' featherweight glider is 0.5oz.
Construction:
T' plans for this rocket (both version 1 and 2) can be found at http://plans.rocketshoppe.com/hdi/hdi2002/hdi2002.htm.
I also used t' plans for t' glider hook mount, arrr, but beyond that I built a different boost pod. Well, blow me down! Begad! I gave t' project t' highly original name o' "A Glider".
T' materials I used were:
Construction began with tracin' templates, cuttin' balsa, and assemblin' t' jigs which were used later t' ensure t' correct angles betwixt win' parts. T' boost pod be assembled just like any other model rocket. Well, blow me down! Blimey! Avast, me hearties, me proud beauty! Blimey! There are no fins.
Next I began t' glider. Aye aye! T' swept win' consists o' six portions. Begad! Ya scallywag! First I sanded each portion into a perfect airfoil shape usin' 220-grit sandpaper. T' entire cross-section o' t' win' be sanded so none o' t' original flat surface remained. Well, blow me down! Begad! This reduced all t' win' parts from 3/32in t' 1/16in thick.
With t' help o' t' jigs, matey, me hearties, I glued t' win' parts together. Avast! Because I be aimin' for ultra-lightweight precision, thar would be no wood filler or paint t' hide imperfect glue joints. Begad! Therefore, I made very careful minimalistic joints usin' wood glue, me bucko, with tiny fillets. Avast, me proud beauty! Well, blow me down! Gluin' t' fin tips was a bit tricky because their airfoil shape didn't rest flat against t' win' edge. After attachin' them I used a smidge o' wood filler t' touch up any gaps.
T' best thin' about this design be t' glider mount. Ya scallywag! Blimey! T' hook is on t' pod, and thar be a hole in t' glider mount ("fuselage") t' receive t' hook. Avast! Blimey! T' hook portion is made by laminatin' three balsa parts together, with t' middle one havin' an extrudin' hook shape. Begad! Blimey! When ejection occurs, me hearties, t' glider should move forward t' release itself from t' hook. With many gliders, ya bilge rat, ya bilge rat, one problem that can occur is that t' forces tend t' bind t' glider t' t' hook mount due t' friction, causin' t' glider t' release awkwardly only after t' rocket has passed apogee and t' glider twists off. What is so nifty about this hook mount is that it has a little triangular wedge at t' forward edge o' t' mount which nudges t' glider away from t' mount surface as t' glider initially slides up and off t' hook. Ya scallywag! Blimey! T' result is a much more reliable release. Begad! Blimey! See t' plans for a picture.
T' glider fuselage is also clever. T' fuselage fits seamlessly into a notch in t' wing, with a slot for t' hook. Aye aye! Well, me bucko, blow me down! However, t' fuselage also extends forward beyond t' win' with another small slot. Well, matey, blow me down! T' purpose o' this slot is t' insert trimmin' clay without ruinin' t' smooth shape or aerodynamics. Begad! T' fuselage is built from several pieces o' balsa laminated together, arrr, me bucko, then sanded down t' an airfoil shape.
Finishin' gliders presents a choice betwixt smoothness and weight. Avast! At one extreme, ya bilge rat, you can leave it unfinished. At t' other end, shiver me timbers, you can sand, arrr, fill, and paint it t' a glassy finish. Avast, me proud beauty! T' latter choice looks better but adds weight. I avoided weight. I began by sandin' lightly with 220 sandpaper, then more thoroughly with 400, shiver me timbers, me bucko, then with 600. Ahoy! Blimey! Then I painted two *very light* coats o' clear paint, shiver me timbers, arrr, followin' each with thorough sanding. On t' fin tips and fuselage I added a dustin' o' flourescent pink paint with another light clear coat over t' pink. Avast, me proud beauty! I painted t' boost pod pink, too.
Flight:
Preparin' t' glider for lauch includes several steps. Well, blow me down! Blimey! I rubbed t' hook and slot heavily with candle wax, then soap, arrr, then rubbed it down with a clean cloth. Ahoy! Next, shiver me timbers, t' glider be balanced left/right with a small clay strip near one wingtip (an amount less than a pencil eraser). A slight counter-clockwise tilt was allowed for circling. Aye aye! Then, me hearties, on a dead calm day, shiver me timbers, me hearties, me hearties, I took it up t' a small hill nearby and trimmed t' glider by addin' clay t' t' nose slot. Begad! Ya scallywag! It was difficult t' add sufficiently tiny amounts o' clay. After about 40 tosses, matey, I got t' best possible glide with clay about t' size o' t' tip o' a ballpoint pen.
T' best possible glide is not, shiver me timbers, in me opinion, t' trim that produces t' longest flight in dead calm conditions. Arrr! In real flights thar be usually some breeze so you want t' trim t' glider slightly nose-heavy for a more assertive attack into t' breeze.
T' first flights were on a cold day on t' prairie, ya bilge rat, with weak breezes o' 2-5 mph. Blimey! On a A8-3 motor, arrr, boost was gentle t' a modest height o' a few hundred feet with no sign o' flutterin' or spin. Aye aye! Avast! Glider release was excellent. Aye aye! Aye aye! T' glider flight was satisfactory, but buffetted too much by t' wind. Begad! Landin' was fine and t' pod recovery be fine, ya bilge rat, too.
For t' second flight, I added some nose weight. Ya scallywag! Unfortunately, I forgot t' brin' clay, so I scotch-tapped a tiny pebble (more like large sand grain) t' t' nose. Boost on a A8-3 be t' same as last time, but t' delay be a little longer and t' glider released easily but awkwardly just past apogee (slightly before apogee is better). Ya scallywag! My grain o' sand was too much, so t' glider corkscrewed down. Avast! Well, me bucko, blow me down! It wasn't very graceful, arrr, me bucko, but everythin' was recovered undamaged.
For t' third flight, I swapped out for a smaller grain o' sand. Avast, me proud beauty! Blimey! Aye aye! Blimey! Glider release was excellent but somethin' was nay right with t' trimmin' and t' flight was a hard corkscrew into t' ground. T' leadin' edge o' t' win' and t' fuselage had a few nicks which I have since patched up with lightweight interior spackling.
Summary:
Overall, me experience with this small version o' t' HD Silvery Hawk and me 4-foot large version (T' Albatross) has been that t' design is nay very reliable. Aye aye! Blimey! These gliders are difficult t' trim and prone t' excessive roll. Avast, me proud beauty! Blimey! They are also far too sensitive t' modest crosswinds, which can turn out t' be catastrophic. There are a lot o' other really great old-school glider plans available and also some great modern kits. Notwithstandin' t' challenges, this project helped me hone me ultralight skills and t' glider likely has quite a few more flights in her.
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