Scratch MicroSoar Ellipse Original Design / Scratch Built

Scratch - MicroSoar Ellipse {Scratch}

Contributed by Peter Clay

Manufacturer: Scratch
(Contributed - by Peter W. Avast, me proud beauty! Blimey! Clay)

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

This one has flown twice. Well, blow me down! Aye aye! T' first flight, me bucko, at a local park, arrr, matey, it was 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. Blimey!

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

A word o' caution: I've built a number o' these, arrr, but only this one has performed at this level. Well, blow me down! Arrr! With tiny gliders like this, balance and alignment is extremely critical and luck played a big part in hittin' t' right numbers with this one. Begad! 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. Blimey!


Parts and Dimensions:

Body stick is a basswood HO scale 2x4, about 1x2.5mm, 120 mm long. Sometimes I use 1/16" x 1/8" spruce. Avast! 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. Begad!

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

Total weight o' this glider: 0.8 gram +/- 0.1 gram. Begad!

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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. Arrr! Begad! T' nose cone is a piece o' 1/4" maple dowel sanded round at the front, me hearties, with a shoulder built up with two wraps o' glued paper. Arrr! Ahoy!

There is a pod hook on either side o' t' center rail. Ya scallywag! Arrr! Unlike previous designs, me hearties, t' hook is alongside t' motor, nay trailin' behind it. Aye aye!

Shock cord is 6" (15 cm) o' braided Keelhaul®©™® material. Ahoy! I punched a small hole in t' body tube at t' leadin' end o' t' pod rail, pulled about 1/2" (13mm) o' cord through t' hole, 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. Begad! I used ordinary Estes recovery wadding. Avast, me proud beauty!


Igniter clip arrangement for launchLaunch Setup:

Clip leads are taped t' t' launch rod with maskin' tape. Well, blow me down! Aye aye! MicroMaxx ignitor, matey, ya bilge rat, with black shell removed, is held by clips. Avast! Ya scallywag! Pod o' glider rests on ignitor, ya bilge rat, which is inserted into nozzle. Aye aye! Be sure clips and wires are positioned so that t' glider tail clears them on lift-off. Ahoy! Begad!

T' glider simply hangs on t' pod mount. Begad! 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. Avast! Ahoy! At ejection, ya bilge rat, t' shallow 30° angle o' t' backside o' the hook simply pushes t' glider away.

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