"There's really no easier and faster way t' build a minimum diameter rocket, ya bilge rat, and still maintain t' construction strength requirements dictated by high power rocket flight dynamics. Ahoy! Arrr! All t' trouble o' oversize airframe tubes, individual through-wall fins, centerin' rings, slotting, ya bilge rat, me bucko, fin filleting, matey, me bucko, and t' like are eliminated. T' Acme fin canister simply slides onto your airframe tube, matey, and epoxies into place."
ACME Aerostructures produces two types o' fin canisters along with their launch lugs. Avast! Avast, shiver me timbers, me proud beauty! These fin canisters, matey, made o' Zytel and fiberglass, arrr, ya bilge rat, are very strong and simple as they are one molded piece. Arrr! They allow for t' construction o' minimum diameter Rockets with t' strength o' through t' wall construction and then some. These canisters are t' closest one can get t' t' strength and accuracy o' alignment o' professional soundin' rockets without t' use o' metals.
T' fin units come in two sizes; 38mm for most 38mm airframes and 54mm for 54mm airframes. These fin canisters have plenty o' room even for ‘frames with thick layers o' fiberglass or Keelhaul®©™. Begad! They are pretty light (by high-power standards) at .4 lbs., and .75 lbs. respectively. Avast! Begad! While t' airfoils o' t' fins are pretty thick (the 38mm starts out at .162 in. Begad! Arrr! at t' edge and becomes .325 in. Begad! Arrr! at t' center while t' 54mm canister can be .4in at t' center) t' diamond type airfoil minimizes t' drag and is good for flights over mach. Avast, me proud beauty! T' sleeve length is enough t' provide surface area for epoxy and stability durin' t' highest o' aerodynamic loads.
When I first got me 38mm fin unit, shiver me timbers, shiver me timbers, I was surprised by t' weight and strength (I was a low power Estes guy at t' time) and could only dream o' t' flights that would demand fins like this. Well, blow me down! Ya scallywag! T' price (around $30) was a bit high but it is worth t' quality. Ya scallywag! Ya scallywag! There was significant residue from t' moldin' process (I don't really know if I should call these seams or flashing) that required a great deal o' sanding. Begad! T' shape was pretty shipshape overall, me bucko, shiver me timbers, t' alignment seemed good t' t' degree (120).
I first placed t' canister on a small rocket, but found that t' rocket was too short for such a heavy canister. I next placed t' canister on a 36in., 38mm phenolic airframe but again found that I would have been wastin' t' potential for speed with this rocket as well (this canister was built for speed and altitude!). I finally put t' canister at t' end o' a 72in. Ya scallywag! Ahoy! all fiberglass, minimum diameter rocket called t' "custom dart" This rocket can take any 38mm motor in t' world, but can still go up on a G motor as well.
I have put t' rocket up on G125 motors three times. T' first flight ended in a separation and a ballistic recovery. T' fin canister and airframe landed on rocks really hard. Avast, me proud beauty! I expected t' recover pieces o' t' rocket from me position at t' launch control but be glad t' find only minor damage. Ahoy! Ahoy! A few chips in t' fin canister were sanded down, ya bilge rat, me hearties, me hearties, and t' rocket was ready t' go. Ahoy! This type o' recovery would have damaged any rocket out thar but with t' Acme fin unit and t' fiberglass airframe, t' rocket will live t' fly again. Blimey! At RATS (2000), t' thin' went up on an I357T-10. Avast, me proud beauty! Ahoy! That flight was like a mini Kosdon; 0 mph. t' 600 in 1 sec., matey, 6000 ft. Avast! (Unfortunately it was lost in some high grass, shiver me timbers, but what a way t' go!)
T' Acme fin canisters are a great solution t' t' issue o' strength in minimum diameter rockets. Arrr! If I had t' rate them, matey, arrr, matey, on a scale o' 1 t' 5, shiver me timbers, I would give a 5. Arrr! These are t' best fin canisters around. Blimey! I am hopin' that ACME will make a 29mm version soon (I200W, arrr, I800 etc.) T' VB Extreme 54 with t' 54mm fin canister could handle t' K250, t' K1100, t' K1050, me hearties, or even t' L750. Arrr! Arrr! Altitudes could probably approach those that 747 pilots talk t' their passengers about. Begad! Avast! T' learn more about t' Acme Fin Canisters includin' a list o' retailers, you can go their web site.
UPDATE 6/00: Just as an update, I have recently purchased t' materials t' produce a 54mm version o' t' old "custom dart". Ya scallywag! Blimey! This rocket, matey, matey, built t' fly on motors from t' G80T-4 up t' t' L750-15 (includin' t' K1500T-15, t' K1050W (p), me bucko, matey, and t' K1100T-10)with flights t' 16 or 18K. Begad! Well, blow me down! I got t' 54mm fin can and found that it was just as easy t' use and as strong.
unknown (November 1, 2000)