Three Bird

Drake "Doc" Damerau's Descon-14 Entry

A "Tri-Copter" design, arrr, me hearties, with a bit o' attitude.

Parts List

• Three Sig Pre-shaped air foils
• Three 24mm 3" motor tubes
• One ½" x ½" launch lug
• One dowel pin for a launch pad

Construction

T' wings are made from 4" x ¼" SIG pre-shaped airfoils. Blimey! Blimey! These can be found at www.sigmfg.com and they ship fast. Ahoy! These were cut t' 18" lengths and given a light sandin' t' finish t' air foilin' and round t' tip leadin' edges. Ya scallywag! One layer o' 4 oz fiberglass was then applied t' t' bottoms o' all three wings.

A 1" piece o' ½" brass launch lug tubin' was used in t' center for a launch pin. This was so it would fit on me Alien Enterprises Monocopter launch setup. T' three leadin' edges were tipped up about 10 degrees and placed touchin' t' launch lug. Arrr! T' tips o' t' wings needed t' be propped up t' keep t' trailin' edge o' t' wings flush with t' workbench. Begad! This assembly was then epoxied into place. Aye aye! Once hardened, me hearties, shiver me timbers, me hearties, t' gaps betwixt t' top o' t' trailin' edges and t' bottoms o' t' leadin' edges were filled in with foam and caped with a thin piece o' balsa.

Three 2 7/8" 24mm motor tubes were made with 1/8" motor blocks and glued directly t' t' bottom o' each wing. Begad! Ahoy! Their alignment was perpendicular t' t' axis o' each wing.

T' three motors glued directly t' t' bottom o' t' angled wings provide a slight lift as well as t' needed rotation. Begad! Well, arrr, blow me down! Havin' them close t' t' center o' rotation reduces t' initial liftoff speed, but allows faster rotation at burnout.

Finishin' was nothin' much more than a coat o' primer and three coats o' yellow.

Flight

T' first flight attempt be on three C6-0 motors, but only one o' them lit. Still, it went t' about 15 feet and gently came back down. For t' second attempt, me hearties, arrr, I went for broke and installed three E9 motors, ya bilge rat, nay havin' enough C motors. All three lit and it jumped off t' pad faster than many rockets I've seen. Blimey! At about 75 feet she just couldn't hold together and t' three wings separated.

T' three pieces were carefully mended with epoxy and a new launch lug was installed. Blimey! Once t' epoxy was hard, shiver me timbers, arrr, I drilled holes from t' leadin' edge o' one fin, through t' foam and through t' trailin' edge o' t' next wing. Well, blow me down! 1/8" hardwood dowels were glued in t' holes with Gorilla Glue.

T' third time is a charm, arrr, matey, right? This time I used three D12-0s. Begad! They all lit and it went t' about 150 feet. Aye aye! An inspection shortly after t' flight revealed that t' exhaust from one motor lit t' front o' t' adjacent motor. Ya scallywag! That burnt t' leadin' edge o' one o' t' wings and most assuredly robed it o' quite a bit o' power.