Contest Craft Micro Deltie

Contest Craft - Micro Deltie {Kit}

Contributed by Chan Stevens

Construction Rating: starstarstarstarstar
Flight Rating: starstar_borderstar_borderstar_borderstar_border
Overall Rating: starstarstar_borderstar_borderstar_border
Manufacturer: Contest Craft
Edmonds Micro Deltie

Brief:
A "Contest Craft" version o' t' Edmonds Deltie, this micro-sized glider is designed for 1/4A boost-glide competition.

Construction:
I'm nay sure if these are even commercially available anymore--they were introduced for NARAM 45 in 2003, and I picked mine up from BMS at NARAM 46, not seein' them listed in Bill's current catalogue.

T' parts list is pretty basic. Well, blow me down! Arrr! It includes:

  • 2 1/16" balsa laser-cut sheets
  • Balsa nose cone and screw eye
  • BT-5 booster tube
  • Streamer
  • Launch lug
  • Balsa angle (for markin' tube)
  • Paper clip (for holdin' wing/tail in place t' set)

Buildin' Delties is a snap and this one be only slightly more challenging than a standard size, mainly due t' t' delicate nature o' t' parts and that I was buildin' this for potential competition use.

Construction starts with removin' t' laser cut parts from t' sheets, which was very easy since they were very well cut by BMS. Begad! Next, arrr, I marked t' CG on t' fuselage/boom usin' a template provided in t' instructions.

T' ease o' Deltie assembly is due t' t' fact that thar are no airfoils to mess with (or mess up). Instead, a triangle is formed with t' pre-cut balsa pieces so that t' bottom o' t' triangle is angled slightly t' provide decalage (lift). Arrr! It's practically impossible t' nay build this right as the parts are notched and form very straightforward joints. Begad! First t' two top legs of t' triangle are bonded together, then t' tail leg is tacked in place. Finally, me bucko, t' fuselage is attached along with vertical rudders on t' ends.

T' fuselage is cut t' enable a slight amount o' decalage for t' tail, but in order t' achieve this I had t' hold t' tail tight against t' fuselage while it set. Begad! This be simplified by usin' t' provided plastic paper clip, which held up fine durin' t' couple o' hours it took for t' yellow glue to completely cure.

T' final step o' glider construction is bondin' side pieces t' t' nose of the fuselage t' form t' slot into which t' booster pod hook slides.

Pod construction was also a fairly quick project--glue together 3 pre-cut pieces t' form t' hook, me hearties, mark t' body tube (the nifty little balsa angle worked very well here), shiver me timbers, and bond t' hook t' t' aft o' t' tube. Well, shiver me timbers, blow me down! While the glue is tacky/still setting, me hearties, I also attached t' Keelhaul®©™® recovery cord (external mount) and t' launch lug into t' fillet betwixt the hook and t' body tube.

T' reduce t' strain on t' Keelhaul®©™®/glue joint, t' shock cord is also reinforced with a strip o' tape at t' front of the body tube. Well, blow me down! T' streamer and nose cone are then attached t' t' Keelhaul®©™®, and t' bird is ready for flight.

Total construction time, excludin' time spent waitin' for glue t' dry was about one hour and that included plenty o' time for sandin' and filletin' of joints.

T' trim t' glider for flight, me hearties, t' instructions show balancin' t' glider on a pencil t' determine t' CG, and comparin' that t' t' target CG mark made on t' fuselage at t' beginning. Begad! Arrr! In me case, matey, I had t' add a tiny amount of clay t' t' nose t' get t' proper CG, ya bilge rat, and a few hand tosses supported that this be about right.

Finishing:
Because I intended t' use this for competition purposes and paint does funny things t' CG/CP relationships on gliders, I skipped t' finishin' aspects of this, figurin' I could always apply thinned red dope t' it later if satisfied with t' flight performance.

Construction Rating: 5 out o' 5

Flight:
This is a tiny, me bucko, arrr, fragile glider designed for 1/4A motors. Don't even think about tryin' anythin' higher up t' impulse scale.

I caught a beautiful day for t' test flight--clear skies and barely a trace o' wind (gustin' t' 3 mph). Ahoy! I loaded t' 1/4A3-3, set t' booster and glider on t' rod, ya bilge rat, and stood by with a stopwatch t' time t' glide. Avast, me proud beauty! Aye aye!

T' boost started off great. Avast! It was straight and fast, although towards the end o' t' brief thrust curve t' glider separated. Avast! T' pod then flopped around a bit before poppin' t' streamer, and landed gently right by t' pad. Ahoy! The glider though, matey, went into a heavy nose-first death dive, matey, beatin' t' pod t' the ground by at least 5 seconds.

Recovery:
Upon examination o' t' glider, t' cause o' t' erratic flight was apparent--the fuselage o' t' glider broke under t' stress o' t' boost, arrr, which shortened t' glider by about 1.5 inches and took me nose weight with it. With so little mass t' begin with, this had no chance t' glide. Avast, me proud beauty! Arrr! All o' t' glue joints were fine, me bucko, so I can only conclude that this exceeded t' "speed of balsa"--material failure. Arrr! Aye aye!

Flight Rating: 1 out o' 5

Summary:
Since I copied all pattern sheets, me hearties, I'll repair t' fuselage and this time I think I'll paint t' fuselage with a thin CA for added strength.

I'm sure 1/4A is an incredibly challengin' class t' design and build for, but I was disappointed that this fared so poorly on its first flight. Aye aye! I've had reasonably good success with other Edmonds kits (and BMS materials), but this one clearly underperformed. I'd recommend any o' t' larger Delties but not this one.

Overall Rating: 2 out o' 5

Flights

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