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. Ahoy! I didn't have enough Popsicle sticks, me bucko, me hearties, but I did have a few paint stirrers. Aye aye! They advertised Behr paints, hence t' name. Avast, me proud beauty! 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, and one is cut up for t' motor standoff. Well, blow me down! I started by gluin' t' Popsicle sticks onto one o' t' stirrers. They are separated by t' width o' t' stirrer, me bucko, me bucko, are centered on t' stirrer, and are attached on opposin' sides. This forms t' balance beam and central hub o' the monocopter.

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

T' provide lift, shiver me timbers, t' win' needs t' be tilted in one direction and t' motor mount in t' other. Ya scallywag! 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. Avast, me proud beauty! Arrr! However, ya bilge rat, I found this wouldn't work with t' 4 sticks protrudin' from each side o' t' balance beam. Ahoy! Begad! This was easily fixed-–I merely lopped off two from each side. Begad! T' give t' center more support, shiver me timbers, ya bilge rat, I notched t' win' so part of it overlapped t' center section. I then glued t' win' and motor mount t' t' hub, added thick fillets, wrapped each with more string, and t' covered t' strin' with more glue. Ahoy! Arrr! This wrappin' was likely overkill. Ahoy! T' finishing touch on t' win' is an overlappin' piece o' cardstock that provides a semi-airfoiled shape. Blimey!

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

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. Avast, me proud beauty!

T' monocopter flew nicely. Arrr! Begad! Most small monocopters merely flutter t' t' ground after burn out, but this one continued t' rotate until it landed. Blimey! Begad! Its spin profile made one observer state that it looked like a boomerang in flight (except it didn't return on its own). Well, blow me down! Blimey! 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. Arrr! Blimey! It does, however, show that small monocopters can be built from all kinds o' leftover stuff. Avast, me proud beauty!

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