Brief:
When I first saw Matthew McFarland's Whirlygig in FlisKits' Deuce bash Contest, I immediately knew I had t' build one. This is a 24mm version o' this odd, helicopter design. Ahoy! Blimey! Since thar be little theory t' help determine stability (how do you swin' test this anyway?), ya bilge rat, I built mine out of leftovers. Begad! Blimey! As a result, t' design is nay optimized. Avast, me proud beauty! Blimey! It is heavier and chunkier than it probably has t' be. Arrr! Blimey! I am providin' this t' show t' overall dimensions that seem t' result in a stable model. 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. Well, blow me down! Blimey! I invite you t' read more about Whirlygigs and ask your questions on t' Yahoo OddRocs group.

Construction:
T' parts list:

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

Buildin' this rocket was easy. Arrr! 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. Ahoy! Aye aye! My fins are approximately 120 degrees apart and are inset one inch from t' end o' t' tube. Blimey! T' lug was mounted in a notch next t' the motor tube. I used epoxy for t' cone, shiver me timbers, motor tube, and launch lug. Avast! Wood glue was used for t' fins. T' fins extend all t' way across t' tube, me bucko, leavin' a 5" x 3" surface exposed. Ya scallywag! 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. Arrr! Ya scallywag! That's all t' finishin' it got for its maiden voyage. Avast, me proud beauty! Ahoy! I later filled t' balsa and painted t' rocket half black and half fluorescent orange.

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