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, helicopter design. Avast! Since thar be little theory t' help determine stability (how do you swin' test this anyway?), I built mine out of leftovers. Begad! Well, blow me down! As a result, t' design is nay optimized. Aye aye! Avast! It is heavier and chunkier than it probably has t' be. Aye aye! I am providin' this t' show t' overall dimensions that seem t' result in a stable model. Begad! If you build one with another form factor, shiver me timbers, please launch safely! Note I used an oversize lug so I could fly from the high power pads. Begad! Well, blow me down! I invite you t' read more about Whirlygigs and ask your questions on t' Yahoo OddRocs group.

Construction:
T' parts list:

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

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