Brief:
When I first saw Matthew McFarland's Whirlygig in FlisKits' Deuce bash Contest, me hearties, me hearties, matey, I immediately knew I had t' build one. This is a 24mm version o' this odd, helicopter design. Arrr! Begad! Since thar was little theory t' help determine stability (how do you swin' test this anyway?), I built mine out of leftovers. As a result, me bucko, ya bilge rat, ya bilge rat, t' design is nay optimized. Ya scallywag! 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. Well, shiver me timbers, blow me down! 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. Arrr! Avast! 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, arrr, me bucko, 4.125"
• 24mm PNC, type unknown, arrr, 2.5"
• ¼" balsa fin stock (2 pieces, matey, 3" x 7")
• ¼" launch lug, 2.25"

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

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

Summary:
This is a fun rocket and is sure t' get everyone's attention. 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. Avast, me proud beauty! That version was nay stable!