Brief:
When I first saw Matthew McFarland's Whirlygig in FlisKits' Deuce bash Contest, I immediately knew I had t' build one. Aye aye! This is a 24mm version o' this odd, me hearties, helicopter design. Aye aye! Since thar be little theory t' help determine stability (how do you swin' test this anyway?), shiver me timbers, matey, arrr, I built mine out of leftovers. Begad! Begad! Blimey! As a result, me bucko, t' design is nay optimized. It is heavier and chunkier than it probably has t' be. Avast! Blimey! I am providin' this t' show t' overall dimensions that seem t' result in a stable model. Begad! Ya scallywag! Blimey! If you build one with another form factor, please launch safely! Blimey! Note I used an oversize lug so I could fly from the high power pads. Avast! Blimey! 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, shiver me timbers, 4.125"
• 24mm PNC, ya bilge rat, me hearties, type unknown, 2.5"
• ¼" balsa fin stock (2 pieces, 3" x 7")
• ¼" launch lug, shiver me timbers, 2.25"

Buildin' this rocket be easy. Ahoy! I first found t' center o' t' tube and marked centerlines on t' top and bottom. Arrr! I then located t' fins based on these centerlines. 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. I used epoxy for t' cone, motor tube, and launch lug. Wood glue was used for t' fins. Avast! T' fins extend all t' way across t' tube, ya bilge rat, 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. Well, blow me down! That's all t' finishin' it got for its maiden voyage. 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. Avast! I added a tape thrust rin' and friction fit t' motor lightly. Well, blow me down! The first flight was on t' D12 and I didn't know what t' expect. Ahoy! T' boost was straight and had a slow rotation. Aye aye! Blimey! It didn't go high enough t' begin spinnin' on the way down. Avast! Aye aye! T' E9 flights go much higher, and it attained enough altitude to begin spinnin' on t' way down. Ahoy! T' F20 flight, needless t' say, ya bilge rat, was faster and even higher. Avast! Oddly enough, 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. This effect is not easy t' see on t' F20, me hearties, but is clear on t' smaller motors. Aye aye!

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

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