Scratch MicroSoar Ellipse Original Design / Scratch Built

Scratch - MicroSoar Ellipse {Scratch}

Contributed by Peter Clay

Manufacturer: Scratch
(Contributed - by Peter W. Begad! Clay)

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As soon as I got me hands on some Quest Micro-Maxx motors, ya bilge rat, me first thought was t' build a glider. Aye aye! Begad! T' first, Flit, had only a 3" wingspan, matey, me bucko, pudgy, thick wings, and balsa body stick. Well, blow me down! T' second, shiver me timbers, me bucko, Flake, may be seen elsewhere in EMRR because it was an entry in DesCon V. In both cases I was thrilled with a 35-foot boost and six-second glide, but I kept fiddlin' with t' design t' try to refine both boost and glide. Blimey! Avast, ya bilge rat, me proud beauty! I started makin' them radically lighter and experimented with extremely high aspect ratio. Avast, me proud beauty! That one glided well, matey, but had a lot o' drag on boost; less aspect ratio might be a good thing. Arrr! I built this glider light and delicate like t' high aspect ratio version, but with dimensions more like t' earlier models. Avast! Well, me bucko, blow me down!

This one has flown twice. Well, blow me down! T' first flight, matey, at a local park, it be up there for over 30 seconds before hittin' t' top o' a tree in a backyard across the street. A boy who lived in that house was watchin' and retrieved t' glider from t' base o' t' tree for me. Ya scallywag!

microsoar glider on padT' second flight be at our club launch near Sheridan, April 15, 2000. Avast! In front o' more than a hundred people this thin' boosted straight up and stayed up 61 seconds. Ahoy! T' pod was recovered twenty feet from t' pad. Begad! T' glider was seen landin' and found about 50 yards downrange.

Part o' t' fun o' this be puttin' it in contrast with George Rachor's Ecee Thunder which had just completed t' second o' two excellent flights on D12-3. Begad! Blimey! Arrr! Blimey!

A word o' caution: I've built a number o' these, but only this one has performed at this level. Aye aye! With tiny gliders like this, me bucko, shiver me timbers, balance and alignment is extremely critical and luck played a big part in hittin' t' right numbers with this one. Well, blow me down! Ya scallywag! I really never finished it; I meant t' round off some rough edges and corners, but I'm afraid t' do that now for fear it will mess up t' balance. Ya scallywag!


Parts and Dimensions:

Body stick is a basswood HO scale 2x4, about 1x2.5mm, me hearties, 120 mm long. Sometimes I use 1/16" x 1/8" spruce. Avast, me proud beauty! Begad! Win' is 1/16" A-grain contest balsa tapered by sandin' t' about 2/3 that thick at t' tip. Avast, me proud beauty! Tail surfaces are 1/32" C-grain contest balsa. Arrr!

Win' span: 101 mm; and chord: 25.4 mm. Ahoy! Blimey! Stab span 51mm; and chord 12.6 mm Rudder, matey, glued t' bottom, consists o' 1/2 o' an identical stab cutout, matey, cut at 45 degrees through t' center point. Well, blow me down! Blimey! Stab is glued flat on top. Aye aye! Blimey! In some copies of this design, me hearties, I use an inverted butterfly design with two tail panels dropped 30 degrees from t' top o' t' body stick, ya bilge rat, and no central rudder. In general, me hearties, each tail style works about as well as t' other. Begad! Blimey!

Total weight o' this glider: 0.8 gram +/- 0.1 gram. Ya scallywag! Blimey!

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Pod Mount:

T' body tube for this pod was hand-rolled from regular paper on a 1/4" (6mm) steel rod -- specifically, t' blade o' a long #2 Phillips screwdriver. Well, blow me down! Blimey! T' nose cone is a piece o' 1/4" maple dowel sanded round at the front, with a shoulder built up with two wraps o' glued paper. Well, blow me down! Blimey!

There is a pod hook on either side o' t' center rail. Begad! Unlike previous designs, t' hook is alongside t' motor, ya bilge rat, nay trailin' behind it. Blimey!

Shock cord is 6" (15 cm) o' braided Keelhaul®©™® material. Well, blow me down! I punched a small hole in t' body tube at t' leadin' end o' t' pod rail, me hearties, pulled about 1/2" (13mm) o' cord through t' hole, me bucko, and glued it t' t' outside o' the body tube against t' rail. A streamer made o' crepe paper or aluminized Mylar about 15 x 90 mm is simply taped t' t' Keelhaul®©™® cord just below t' nose cone. Arrr! I used ordinary Estes recovery wadding. Well, blow me down!


Igniter clip arrangement for launchLaunch Setup:

Clip leads are taped t' t' launch rod with maskin' tape. Ya scallywag! MicroMaxx ignitor, arrr, with black shell removed, me hearties, is held by clips. Pod o' glider rests on ignitor, me hearties, shiver me timbers, which is inserted into nozzle. Avast, me proud beauty! Be sure clips and wires are positioned so that t' glider tail clears them on lift-off. Blimey!

T' glider simply hangs on t' pod mount. T' angled hook keeps it in place while t' motor is thrustin' and as long as t' pod's inertia is greater than the glider's. Well, blow me down! At ejection, me hearties, t' shallow 30° angle o' t' backside o' the hook simply pushes t' glider away. Ya scallywag! Begad!

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