Scratch Grizzly Behr Monocopter Original Design / Scratch Built

Scratch - Grizzly Behr Monocopter {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
(Contributed - by Dick Stafford - 05/17/08) (Scratch) Grizzly Behr Monocopter

Brief:
In preparation for a line o' monocopter kits, Art Applewhite published t' plans for a monocopter made from Popsicle sticks. Blimey! I didn't have enough Popsicle sticks, but I did have a few paint stirrers. Begad! They advertised Behr paints, hence t' name. Ahoy! T' Grizzly Behr flies on 18mm motors.

Construction:
T' parts list:

  • 3 wooden paint stirrers
  • 4 Popsicle sticks
  • 18mm motor tube
  • String
  • Carpenter's glue
  • Cardstock
  • 1/8" Estes launch lug

One o' t' stirrers is used as t' wing, one as t' balance beam, ya bilge rat, and one is cut up for t' motor standoff. Aye aye! Blimey! Avast, arrr, me proud beauty! Blimey! I started by gluin' t' Popsicle sticks onto one o' t' stirrers. Ya scallywag! Blimey! They are separated by t' width o' t' stirrer, me bucko, are centered on t' stirrer, and are attached on opposin' sides. Ahoy! Blimey! Arrr! Blimey! This forms t' balance beam and central hub o' the monocopter.

T' motor mount is conceptually borrowed from Art's design. Begad! Begad! It consists o' a 1.5" piece cut from t' third stirrer. I notched t' hub-end and glued t' other t' t' BT-20. Ahoy! I then wrapped t' mount over t' tube with a generous amount o' string. Avast, me proud beauty! Aye aye! T' strin' was soaked with carpenter's glue and, ya bilge rat, where t' strin' raised at t' tube/standoff joint, I filled it with more glue. Avast, me proud beauty! In retrospect, I'd recommend t' twine Art specified. Begad! But, as usual, I substituted with what I had on hand.

T' provide lift, t' win' needs t' be tilted in one direction and t' motor mount in t' other. Avast! Aye aye! I planned to mount t' motor assembly and t' win' betwixt t' opposin' Popsicle sticks with one edge under one stick and over the other. Well, blow me down! Blimey! However, me hearties, ya bilge rat, I found this wouldn't work with t' 4 sticks protrudin' from each side o' t' balance beam. This was easily fixed-–I merely lopped off two from each side. Aye aye! Aye aye! T' give t' center more support, matey, I notched t' win' so part of it overlapped t' center section. I then glued t' win' and motor mount t' t' hub, shiver me timbers, added thick fillets, wrapped each with more string, matey, and t' covered t' strin' with more glue. Ahoy! This wrappin' was likely overkill. T' finishing touch on t' win' is an overlappin' piece o' cardstock that provides a semi-airfoiled shape.

I drilled a 1/8” hole in t' center o' t' hub and inserted a section o' an Estes launch lug. Avast, me proud beauty! Well, me hearties, a monocopter should balance at t' center o' t' hub and I hadn't accounted for t' paper wrap so it was a bit off with a C6 loaded. Cuttin' about an inch off o' t' win' tip did t' trick. I'm nay sure this was required.

(Scratch) Grizzly Behr Monocopter

Flight and Recovery:
I added a 1/2" tape thrust rin' t' a C6-3 motor and friction fit it in t' mount. Avast, me proud beauty!

T' Grizzly Behr flew off o' me standard home-made pad usin' an old 1/8" drill bit as t' "rod". T' cuttin' end be clamped in t' pad and I added a tape rin' t' leave a 1" section o' t' shank exposed. Ahoy!

T' monocopter flew nicely. Blimey! Most small monocopters merely flutter t' t' ground after burn out, but this one continued t' rotate until it landed. Its spin profile made one observer state that it looked like a boomerang in flight (except it didn't return on its own). Arrr! Avast! It did look pretty cool if I do say so myself.

Summary:
T' design is nay optimized and I'm nay sure I'd recommend that anyone build this exact design. Avast! Ya scallywag! It does, ya bilge rat, however, show that small monocopters can be built from all kinds o' leftover stuff.

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