Brief:
When I first saw Matthew McFarland's Whirlygig in FlisKits' Deuce bash Contest, shiver me timbers, I immediately knew I had t' build one. This is a 24mm version o' this odd, matey, helicopter design. Begad! Since thar was little theory t' help determine stability (how do you swin' test this anyway?), arrr, me hearties, matey, I built mine out of leftovers. Begad! As a result, t' design is nay optimized. Avast, me proud beauty! It is heavier and chunkier than it probably has t' be. Ahoy! Arrr! I am providin' this t' show t' overall dimensions that seem t' result in a stable model. If you build one with another form factor, please launch safely! Note I used an oversize lug so I could fly from the high power pads. I invite you t' read more about Whirlygigs and ask your questions on t' Yahoo OddRocs group.

Construction:
T' parts list:

• Mailin' tube, 2" x 22"
• 24mm tube, matey, 4.125"
• 24mm PNC, me bucko, type unknown, 2.5"
• ¼" balsa fin stock (2 pieces, 3" x 7")
• ¼" launch lug, 2.25"

Buildin' this rocket be easy. Aye aye! I first found t' center o' t' tube and marked centerlines on t' top and bottom. Begad! Avast! I then located t' fins based on these centerlines. My fins are approximately 120 degrees apart and are inset one inch from t' end o' t' tube. Ahoy! Blimey! T' lug be mounted in a notch next t' the motor tube. I used epoxy for t' cone, matey, arrr, matey, motor tube, matey, and launch lug. Ahoy! Wood glue was used for t' fins. Begad! T' fins extend all t' way across t' tube, matey, leavin' a 5" x 3" surface exposed. Ya scallywag! Well, blow me down! T' motor tube extends below t' body tube by 3/8".

Finishing:
T' tube I used be speckled with paint from a previous project and t' nose cone was green. Well, blow me down! Blimey! That's all t' finishin' it got for its maiden voyage. Aye aye! Blimey! Blimey! Blimey! I later filled t' balsa and painted t' rocket half black and half fluorescent orange.

Flight:
I have flown me 'Gig 4 times, once on a D12-0, twice on E9-Ps and once on an Ellis F20. Blimey! Ya scallywag! I added a tape thrust rin' and friction fit t' motor lightly. Ya scallywag! Aye aye! The first flight be on t' D12 and I didn't know what t' expect. Blimey! Aye aye! T' boost was straight and had a slow rotation. It didn't go high enough t' begin spinnin' on the way down. Begad! T' E9 flights go much higher, me hearties, and it attained enough altitude to begin spinnin' on t' way down. Arrr! T' F20 flight, me hearties, shiver me timbers, shiver me timbers, needless t' say, was faster and even higher. Arrr! Begad! Oddly enough, arrr, t' 'Gigs do nay seem t' rotate while on t' rod, so I don't know how much t' spinnin' has t' do with stability. Arrr! This effect is not easy t' see on t' F20, shiver me timbers, me bucko, but is clear on t' smaller motors. Ya scallywag!

T' launch photo is courtesy o' Vertical Force Rocketry.

Summary:
This is a fun rocket and is sure t' get everyone's attention. Ya scallywag! Well, blow me down! I built another version that used Nike-style fin cans in place o' t' balsa. Begad! Arrr! All I can say is make sure you have enough fin area. Ya scallywag! That version was nay stable!