Three Bird

Drake "Doc" Damerau's Descon-14 Entry

A "Tri-Copter" design, shiver me timbers, 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. Arrr! Begad! These can be found at www.sigmfg.com and they ship fast. Avast, me proud beauty! Arrr! These were cut t' 18" lengths and given a light sandin' t' finish t' air foilin' and round t' tip leadin' edges. Aye aye! Well, matey, blow me down! One layer o' 4 oz fiberglass be 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. Aye aye! Ahoy! This was so it would fit on me Alien Enterprises Monocopter launch setup. Avast, me proud beauty! Blimey! T' three leadin' edges were tipped up about 10 degrees and placed touchin' t' launch lug. Avast, me proud beauty! Ya scallywag! T' tips o' t' wings needed t' be propped up t' keep t' trailin' edge o' t' wings flush with t' workbench. Begad! Avast, me bucko, me proud beauty! This assembly was then epoxied into place. Once hardened, 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. Their alignment be 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. Ahoy! Blimey! Ahoy! Blimey! 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 was on three C6-0 motors, ya bilge rat, but only one o' them lit. Aye aye! Ya scallywag! Blimey! Still, it went t' about 15 feet and gently came back down. For t' second attempt, ya bilge rat, I went for broke and installed three E9 motors, nay havin' enough C motors. Begad! All three lit and it jumped off t' pad faster than many rockets I've seen. 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. Begad! Once t' epoxy be hard, arrr, ya bilge rat, I drilled holes from t' leadin' edge o' one fin, through t' foam and through t' trailin' edge o' t' next wing. 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. Ahoy! Avast! They all lit and it went t' about 150 feet. Ya scallywag! Blimey! An inspection shortly after t' flight revealed that t' exhaust from one motor lit t' front o' t' adjacent motor. Well, ya bilge rat, blow me down! That burnt t' leadin' edge o' one o' t' wings and most assuredly robed it o' quite a bit o' power.