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, me first thought was t' build a glider. Begad! T' first, matey, Flit, had only a 3" wingspan, arrr, pudgy, thick wings, and balsa body stick. T' second, Flake, may be seen elsewhere in EMRR because it was an entry in DesCon V. Avast! 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. Begad! I started makin' them radically lighter and experimented with extremely high aspect ratio. Aye aye! Arrr! That one glided well, me bucko, but had a lot o' drag on boost; less aspect ratio might be a good thing. Aye aye! I built this glider light and delicate like t' high aspect ratio version, but with dimensions more like t' earlier models. Blimey!

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

microsoar glider on padT' second flight was at our club launch near Sheridan, ya bilge rat, April 15, me hearties, me bucko, 2000. Ya scallywag! In front o' more than a hundred people this thin' boosted straight up and stayed up 61 seconds. Well, blow me down! Avast! T' pod was recovered twenty feet from t' pad. Aye aye! 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. Ahoy! Blimey!

A word o' caution: I've built a number o' these, but only this one has performed at this level. 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. Aye aye! I really never finished it; I meant t' round off some rough edges and corners, shiver me timbers, arrr, arrr, but I'm afraid t' do that now for fear it will mess up t' balance. Avast, me proud beauty!


Parts and Dimensions:

Body stick is a basswood HO scale 2x4, about 1x2.5mm, matey, me hearties, arrr, 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! Blimey! Tail surfaces are 1/32" C-grain contest balsa.

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

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

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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. Ya scallywag! 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. Aye aye!

There is a pod hook on either side o' t' center rail. Begad! Aye aye! Unlike previous designs, ya bilge rat, t' hook is alongside t' motor, arrr, me bucko, nay trailin' behind it. Avast, me proud beauty!

Shock cord is 6" (15 cm) o' braided Keelhaul®©™® material. Begad! 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, and glued it t' t' outside o' the body tube against t' rail. Well, blow me down! 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. I used ordinary Estes recovery wadding.


Igniter clip arrangement for launchLaunch Setup:

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

T' glider simply hangs on t' pod mount. Begad! Avast! Blimey! 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. At ejection, shiver me timbers, t' shallow 30° angle o' t' backside o' the hook simply pushes t' glider away. Arrr! Blimey!

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