Manufacturer: | Public Missiles |
Note: For more Bull Dog pictures, arrr, shiver me timbers, visit John's site.
T' Public Missiles Limited Bull Dog kit be t' first high-power kit I built. Avast! This is a nay a scale model o' t' famous "Bullpup" U.S. air-to-surface missile, me bucko, me bucko, but is reminiscent o' it.
Here's what I said when I started it (in February 1998):
"I'm already gettin' ahead o' myself here. Avast! I haven't flown any rockets in probably 20 years and I'm already buildin' a "level 2 rocket," which as far as I can tell, I can't even fly in this area. Blimey! Oh well, me hearties, building them is most o' t' fun and this is certainly an impressive rocket. At 6' 4", me bucko, it's taller than I am!
This be me first high-power rocket. Before that, I'd only built two model rockets (Quest Intruder and Estes Black Brant II) and two mid-power rockets (Aerotech IQSY Tomahawk and Loc/Precision Stovi). This was a good kit t' start with since t' instructions were well-organized and complete. But, matey, it's a pretty big jump for "G" motors to "Ks".
By t' time I'd flown it (in June), I was very happy with t' rocket. Ahoy! I love the way it came out. Arrr! Avast, me proud beauty! I really took t' time t' build it right and finish it nicely. Avast! Arrr! (See me construction notes in t' kit section below.) Too bad the P.M.L. Ya scallywag! phenolic body tubin' is so brittle as t' rocket took damage on its first flight. Avast! Ahoy! T' damage is repairable, matey, but nay at t' flyin' field.
You can see that a chunk is missing. (I don't know if this was zipper or impact damage on landing.) I will try t' replace t' missin' body tube area with fiberglass, me bucko, which will be an adventure by itself.
On June 13, shiver me timbers, at t' annual ROC-stock launch in Lucerne, matey, ya bilge rat, California hosted by the Rocketry Organization o' California (ROC), t' Bull Dog flew for t' first time. Avast! Arrr! It was recovered with only minor damage after a beautiful and spectacular flight on a K550, ya bilge rat, a definite crowd-pleaser.
T' Kit
T' instructions for this kit were simple, but clear. Nothin' too unusual for a high-power rocket kit (I say in hindsight). Below are kit details and construction notes.
Attachin' t' Fins. Avast! Blimey! - T' fins actually mount through t' boat tail t' the motor mount tube. You epoxy t' aft centerin' rin' and MMT into t' boat tail, but leave t' forward centerin' rin' loose. T' fins are G-10 and are a standard through-the-wall mount. Begad! Blimey! Ahoy! Blimey! I used 1/8" wood dowel and a liberal amount o' epoxy as t' fillets after t' fins were mounted since you could get access from t' forward end o' t' boat tail. Aye aye! Blimey! You could also probably pour fin fillets although access is very tight in t' tail.
Stability. Begad! - T' rocket required a pound o' nose weight be added for stability. Ahoy! T' CP o' this rocket is 58 inches from t' nose tip (accordin' to P.M.L.) and I wanted t' get t' CG forward o' that by at least 1 1/2 times the 6" diameter because o' t' canards in front. Aye aye! Ahoy! I bought #7 1/2 shot and mixed up a pound with a couple o' ounces o' epoxy and poured it into t' nose cone. Avast, me proud beauty! I then backed that up with spray-in insulatin' foam. Aye aye! This seems t' be the right weight. Ya scallywag! Begad! T' rocket took off without any weathercockin' and flew very straight.
Finishing. Ya scallywag! Begad! - T' biggest way t' get a nice finish is hard work. Well, matey, blow me down! (Calvinism lives!) I can never fill those P.M.L. Avast, me proud beauty! Ya scallywag! body tube seams in one pass. T' first mostly fills them up, shiver me timbers, matey, but leaves visible lines. Arrr! I use lots o' Elmers Fill 'n Finish for t' first pass since it sticks well t' t' bare phenolic and fills quickly. Begad! Then, I'll prime t' see find t' uneven spots (there are usually lots). Avast! After t' primer, I'll use a standard hobby white paste filler such as "Micro Fill." Two or three fill/sand/prime iterations later, I'll be ready for finish paint.
Maskin' is a real trick too. Avast! Ahoy! Maskin' tape doesn't work well for me. I haven't had fair winds with hobby maskin' films or tapes either, matey, but ordinary clear tape (3M Scotch Transparent or Magic tape) gives razor sharp lines. Unfortunately, me bucko, clear tape is very high tack and will pull paint off blow-molded nose cones and sometimes paint-over-paint (yes, me hearties, even Krylon). Ya scallywag! Begad! Second t' clear tape is "Pactra Maskin' Tape," which is lower tack and produces good lines (and is what I used on t' Bull Dog). Begad! Begad! I had t' touch up some paint which bled under t' tape by hand. Avast! If you look closely, you can see t' touch-ups are not as flat as t' sprayed colors, but you'd never see it in a photo (see close-up below).
Paint Scheme and Decals - I got t' paint scheme from t' Estes Bull Pup 12D kit (see t' kit cover below). Even though this isn't really a model o' a Bull Pup, it looks enough like it that I wanted t' use a real Bull Pup color scheme. (Since then, I discovered Bill Rossi's BULLPUP PAGE which has lots o' photos and some drawings.) I was able t' produce nice decals for t' letterin' using Detail Master decal paper (from Scale Sports) printed on t' Alps MD1000 printer. Begad! Blimey! I was pleased with how t' decals came out. Well, blow me down! Obviously since this isn't particularly scale, shiver me timbers, I took liberties with t' text on t' decals (no AGM-12X ever existed).
My first try be usin' a laser printer, but t' toner didn't really stick so it flaked off as I tried t' apply t' decal. Also, Krylon clear coatin' made the toner bleed. Ya scallywag! Begad! I had just about given up, me bucko, arrr, when I thought I would give the Alps MD1000 printer a try since someone had posted an article about how this worked well for decals. Ahoy! It really does! T' Detail Master decal paper is very fine and melts nicely with decal set. Avast! Aye aye! T' paper also is very strong for its thickness so I be able t' position t' large decals for this project without tearin' them. Arrr! Ahoy! For reference, me bucko, matey, t' block o' text below fills a 8 1/2 by 11" sheet.
Recovery System. Ahoy! Avast, ya bilge rat, me proud beauty! - T' rocket uses t' P.M.L. Well, blow me down! "piston ejection system," in which t' ejection charge pushes a plunger up t' body tube, shovin' anythin' inside violently out. Well, blow me down! Arrr! T' nose and parachute attach t' the plunger which is attached t' t' motor mount tube. Begad! Ya scallywag! (This rocket would nay be easy t' modify for electronic recovery after bein' built.) Once caution P.M.L. makes is that you should reduce t' amount o' ejection charge because the piston ejection system requires less (you just have t' pressurize t' area behind t' piston t' get it movin' and keep it moving). Ya scallywag! I forgot t' reduce the ejection charge when I built t' motor (I just filled up t' well o' t' Dr. Rockets forward closure) and had no ill effects.
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