Brief:
When I first saw Matthew McFarland's Whirlygig in FlisKits' Deuce bash Contest, I immediately knew I had t' build one. Begad! This is a 24mm version o' this odd, helicopter design. Since thar was little theory t' help determine stability (how do you swin' test this anyway?), arrr, I built mine out of leftovers. Avast! As a result, arrr, t' design is nay optimized. Arrr! It is heavier and chunkier than it probably has t' be. Arrr! 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! Note I used an oversize lug so I could fly from the high power pads. Begad! Ahoy! I invite you t' read more about Whirlygigs and ask your questions on t' Yahoo OddRocs group.

Construction:
T' parts list:

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

Buildin' this rocket was easy. Aye aye! Well, blow me down! I first found t' center o' t' tube and marked centerlines on t' top and bottom. Avast, me proud beauty! I then located t' fins based on these centerlines. Aye aye! 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, me hearties, shiver me timbers, motor tube, and launch lug. Avast, me proud beauty! Aye aye! Wood glue was used for t' fins. Begad! Ahoy! T' fins extend all t' way across t' tube, matey, shiver me timbers, leavin' a 5" x 3" surface exposed. Ahoy! 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 was green. Begad! Ya scallywag! 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, me hearties, ya bilge rat, once on a D12-0, shiver me timbers, shiver me timbers, twice on E9-Ps and once on an Ellis F20. Ya scallywag! 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. Well, blow me down! Aye aye! T' boost was straight and had a slow rotation. Aye aye! Avast, me bucko, me proud beauty! It didn't go high enough t' begin spinnin' on the way down. Begad! T' E9 flights go much higher, and it attained enough altitude to begin spinnin' on t' way down. Arrr! T' F20 flight, matey, needless t' say, ya bilge rat, shiver me timbers, was faster and even higher. Oddly enough, shiver me timbers, me bucko, 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. Aye aye! This effect is not easy t' see on t' F20, me hearties, but is clear on t' smaller motors. Avast!

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 bucko, me proud beauty! Blimey! I built another version that used Nike-style fin cans in place o' t' balsa. Blimey! Blimey! Begad! Blimey! All I can say is make sure you have enough fin area. That version was nay stable!