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

Construction:
T' parts list:

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

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

Finishing:
T' tube I used was speckled with paint from a previous project and t' nose cone be green. Avast, me proud beauty! Ya scallywag! That's all t' finishin' it got for its maiden voyage. Arrr! I later filled t' balsa and painted t' rocket half black and half fluorescent orange.

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

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

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