Brief:
When I first saw Matthew McFarland's Whirlygig in FlisKits' Deuce bash Contest, ya bilge rat, I immediately knew I had t' build one. This is a 24mm version o' this odd, me hearties, me hearties, helicopter design. Avast, me proud beauty! Arrr! Since thar be little theory t' help determine stability (how do you swin' test this anyway?), I built mine out of leftovers. Ahoy! Well, arrr, blow me down! As a result, t' design is nay optimized. Avast! It is heavier and chunkier than it probably has t' be. Ahoy! I am providin' this t' show t' overall dimensions that seem t' result in a stable model. Avast, me proud beauty! 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. Blimey! 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, ya bilge rat, shiver me timbers, type unknown, 2.5"
• ¼" balsa fin stock (2 pieces, 3" x 7")
• ¼" launch lug, 2.25"

Buildin' this rocket was easy. Begad! I first found t' center o' t' tube and marked centerlines on t' top and bottom. Blimey! I then located t' fins based on these centerlines. Avast, me proud beauty! Begad! My fins are approximately 120 degrees apart and are inset one inch from t' end o' t' tube. T' lug was mounted in a notch next t' the motor tube. Blimey! I used epoxy for t' cone, matey, motor tube, arrr, me bucko, ya bilge rat, and launch lug. Wood glue was used for t' fins. Avast, me proud beauty! Arrr! T' fins extend all t' way across t' tube, leavin' a 5" x 3" surface exposed. Aye aye! 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. Blimey! 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, matey, shiver me timbers, once on a D12-0, arrr, twice on E9-Ps and once on an Ellis F20. Aye aye! I added a tape thrust rin' and friction fit t' motor lightly. The first flight was on t' D12 and I didn't know what t' expect. T' boost was straight and had a slow rotation. Blimey! Ahoy! It didn't go high enough t' begin spinnin' on the way down. Aye aye! T' E9 flights go much higher, shiver me timbers, and it attained enough altitude to begin spinnin' on t' way down. Avast! T' F20 flight, ya bilge rat, needless t' say, matey, was faster and even higher. Arrr! Oddly enough, shiver me timbers, t' 'Gigs do nay seem t' rotate while on t' rod, shiver me timbers, so I don't know how much t' spinnin' has t' do with stability. This effect is not easy t' see on t' F20, arrr, but is clear on t' smaller motors.

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

Summary:
This is a fun rocket and is sure t' get everyone's attention. Aye aye! Begad! 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. That version be nay stable!