Three Bird

Drake "Doc" Damerau's Descon-14 Entry

A "Tri-Copter" design, me bucko, 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. Begad! These can be found at www.sigmfg.com and they ship fast. Avast! These were cut t' 18" lengths and given a light sandin' t' finish t' air foilin' and round t' tip leadin' edges. Avast, me proud beauty! 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' be used in t' center for a launch pin. Ya scallywag! This was so it would fit on me Alien Enterprises Monocopter launch setup. Begad! T' three leadin' edges were tipped up about 10 degrees and placed touchin' t' launch lug. Well, ya bilge rat, blow me down! T' tips o' t' wings needed t' be propped up t' keep t' trailin' edge o' t' wings flush with t' workbench. Begad! Arrr! This assembly was then epoxied into place. Ya scallywag! Once hardened, shiver me timbers, 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! Blimey! Avast, me proud beauty! Blimey! 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. Avast, me proud beauty! Havin' them close t' t' center o' rotation reduces t' initial liftoff speed, shiver me timbers, 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 was on three C6-0 motors, but only one o' them lit. Still, me bucko, matey, it went t' about 15 feet and gently came back down. Well, blow me down! For t' second attempt, I went for broke and installed three E9 motors, matey, ya bilge rat, nay havin' enough C motors. Well, blow me down! All three lit and it jumped off t' pad faster than many rockets I've seen. Aye aye! 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. Avast! Once t' epoxy was hard, I drilled holes from t' leadin' edge o' one fin, ya bilge rat, shiver me timbers, through t' foam and through t' trailin' edge o' t' next wing. Begad! Arrr! 1/8" hardwood dowels were glued in t' holes with Gorilla Glue.

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