Construction Rating: | starstarstarstar_borderstar_border |
Flight Rating: | starstarstarstarstar_border |
Overall Rating: | starstarstarstarstar_border |
Published: | 2011-09-27 |
Manufacturer: | Scratch |
This is a scratchbuilt upscaled semi-scale version o' t' Estes Bomarc kit. Avast, me proud beauty! T' rocket actually began life as an Estes "Screamin Mimi" which I had built but never launched. Aye aye! I be never very excited by t' rocket and decided t' try somethin' else with it. Avast! I had extended t' body tube length by 5 1/4" which improved t' "Screamin Mimi" somewhat, but nay enough, t' rocket continued t' linger unflown. Arrr! After havin' built a regular size clone o' t' Estes Bomarc it hit me that I could use t' body tube from t' "Screamin Mimi" t' build a larger Bomarc, which could fly on regular D size engines. Ya scallywag! T' overall size o' t' Bomarc is 28.5" long, diameter o' 1.637", and a wingspan o' 11.5".
For plans I downloaded t' intructions for t' Estes Bomarc from "JimZ." I upscaled t' outlines for t' main wing, ya bilge rat, tail, and aft wings by 1.237 on a copier. Ahoy! I layed t' outlines on t' 1/8" balsa, outlined them with a pencil, arrr, shiver me timbers, and then cut them out with an X-Acto knife. Arrr! All t' pieces were glued together with Elmer's wood glue and allowed t' dry. When t' glue be dry I rounded t' leadin' and trailin' edges o' t' wings and tail. Arrr! Well, blow me down! T' ramjet extensions were cut t' size then sanded t' an airfoil shape. Ahoy! Ahoy! For t' raceway, I cut a 21" long by 1/2" strip from t' 1/4" balsa stock, t' which I laminated a 1/8" strip in order t' make t' raceway 3/8" wide. I sanded a taper into t' front and aft o' t' raceway, and then cut a strip from t' center o' t' aft taper where t' tail would slide in. Avast, me proud beauty! T' raceway be t' least scale like feature o' this model, t' real missile raceway has a halfround cross section whereas mine is basically straight sided. Arrr! Blimey! Next time I will use a long tube sectioned lengthwise with shaped balsa ends. Ya scallywag! T' ramjet cones were created by makin' cones from copier paper. Once t' cone was formed I soaked t' paper with super glue t' strengthen it. Aye aye! Begad! I constructed t' ramjet transitions from thin cardboard by wrappin' it around a pointed BT-55 nose cone and trimmin' by eye until it looked right. Avast, me proud beauty! I glued t' cones into t' transitions which were then glued t' t' end o' t' 6 3/4" tubes. Well, blow me down! Well, matey, blow me down! T' plastic knozzles were super glued t' t' aft o' t' tubes. Avast! T' solid balsa nosecone be hollowed out inside with a power drill in order t' provide room for nose weight which Bomarc models usually require. In this case, t' total weight o' t' nosecone is 5.5 oz. Avast! Due t' t' heavy nose cone I was concerned it would stike t' body tube after ejectin' so I decided t' have it recover on its own chute. Avast, arrr, me proud beauty! Later testin' in t' backyard showed that both t' cone and t' main body needed 24" chutes for slow recovery. Aye aye! T' body tube had been prepared by removin' all t' fins and t' launch lug, ya bilge rat, then sandin' t' paint from t' tube. In order t' ease t' paint removal, ya bilge rat, I sprayed t' tube with oven cleaner which dissolved t' color coat and softened t' primer. With careful work and sandin' t' tube came out smooth and ready for assembly. Arrr! I used wood glue t' attach t' wings, raceway, ya bilge rat, tail, arrr, and ramjets t' t' body tube. Avast, me proud beauty! I made 3/16" launch lugs by wrappin' paper around a launch rod and soakin' it with super glue. Aye aye! Arrr! (after removin' it from t' rod!) I glued one lug under t' aft win' and another under t' main wing. I added shock cords t' t' main body and nosecone usin' t' common Estes method. T' cords don't need t' be very long due t' t' seperate recovery, arrr, arrr, and I made mine from old shoe laces. Aye aye! Although t' Estes plans would have you add antennas t' each o' t' main and tail wings, me bucko, I opted nay t' add these as I feered they might snag t' shock cords or parachutes resultin' in a bad recovery. Once assembly was finished I moved onto finishing.
Finishin' this kit be complicated by usin' a previously painted body tube. Well, blow me down! Blimey! Removin' t' old paint and sandin' t' tube smoothed it out adequately. Avast, me proud beauty! Begad! All t' balsa be sealed with thinned Elmers wood filler and sanded smooth. Avast, me proud beauty! There is a large amount o' wood t' fill... Begad! Next time I will fill t' bottoms o' t' wings and t' ramjet supports prior t' gluin' them t' t' body tube as sandin' these areas was complicated by t' narrow angle betwixt t' tube, shiver me timbers, wing, and supports. Begad! Once fillin' was complete I used some old grey colored Testors paint as a primer. This was a mistake as it never really seemed t' dry, shiver me timbers, shiver me timbers, and clogged sandpaper very quickly, ya bilge rat, next time I will use proper primer. Eventually I acheived a fairly smooth surface and painted t' entire rocket with gloss white Walmart spray paint. T' areas t' remain white were masked off and then I sprayed gloss black "Quick Color" from Home Depot. Well, blow me down! Avast! I should have bought t' better paint, t' "Quick Color" took about six coats t' cover t' white, ya bilge rat, shiver me timbers, and t' finish be inconsistent, some areas smooth and glossy, ya bilge rat, arrr, others dull and dusty, me bucko, with some areas o' small bubbles which did nay cover t' white. After usin' about 3/4 o' t' can I finally had a decent finish. Avast! T' silver areas o' t' ramjets and aft body were masked and sprayed with Testors silver, matey, while t' nosecone received a spray o' Walmart gold, no problems here. Arrr! Once t' paint had dried for a few days I applied t' Tango Papa decals. Well, blow me down! T' decals went on very well, t' white areas were very opaque and cover t' black with no bleed through. Blimey! Unfortunately, me hearties, t' printin' registration was off just a little so thar be a thin edge o' white showin' on t' bottom o' t' star and bar insignia. Arrr! Ahoy! T' decal sheet did nay include t' serial number as with t' original Estes kit, but t' overall appearance o' t' model looks pretty good even without them. Begad! Once everythin' be dry I clear coated t' model with Rustoleum clear gloss. Avast, me proud beauty! Avast, shiver me timbers, me proud beauty! Unfortunately, even tryin' two different cans o' t' clear, it did nay spray smoothly so I again ended up with an inconsistent finish. Perhaps in a few weeks I will wet sand t' clear with fine sandpaper and polish t' get a proper glass smooth finish. Aye aye! Overall though despite me various problems t' Bomarc looks good, even me highly critical wife thinks it looks "Pretty."
Prior t' flight I balanced t' model such that it hung level from a point about one inch in front o' t' main wing, matey, with no engine installed. Never havin' flown a Bomarc model before, shiver me timbers, and havin' heard many stories o' them goin' out o' control I erred on t' side o' caution and may have overdone t' nose weight. Blimey! My rocket seems heavy for its size at just under 13 oz. Begad! Nevertheless when launch day arrived I prepped t' rocket with an Estes D12-3 and about six squares o' wadding. I packed t' nosecone chute into t' body tube first and then t' mainbody chute on top t' ensure both would come out when t' nosecone was ejected. Begad! There be little t' no wind and t' engine ignited on t' first try. Well, blow me down! Blimey! T' Bomarc shot off t' pad as a good clip and slowly rotated around its axis as it climbed nearly straight up t' an estimated 300 feet. Avast, me proud beauty! Begad! At that point t' Bomarc started t' level out as if flyin' toward a distant missile intercept. I have t' say it looked pretty cool, almost like you would expect t' real one t' have looked. Blimey! Arrr! I suspect t' heavy nose had somethin' t' do with t' Bomarc droppin' down t' t' horizontal as it lost airspeed.
T' second flight be about a month later, arrr, this time in winds o' approximately 5 mph. Begad! Ya scallywag! I again used an Estes D12-3. Aye aye! This time t' rocket did nay rotate at all and flew t' a similar height. Avast! Once again t' rocket went horizontal and then ejected shortly after.
After goin' horizontal for about 50 feet t' ejection charge blew and t' nosecone seperated smoothly, with good deployment o' its chute. Begad! T' main chute was pulled free as expected but did nay deploy until about 100 feet up, at which point it filled nicely. Well, blow me down! I caught t' nosecone before it hit t' ground and me recovery assistant daughter caught t' main body, thar was no damage t' either section. Ya scallywag! I probably wrapped t' main chute too tight resultin' in its slow deplyment. Well, blow me down! Begad! Overall it was an excitin' and cool t' watch first flight...
On flight number two, t' nosecone chute did nay fully deploy so it came down fast. T' cone sustained a slight chip in t' tip on landin' but nothin' that can't be touched up. T' main body chute deployed correctly and t' body landed without incident. Avast! T' crowd really seemed t' enjoy t' flight.
T' Bomarc is nay t' easiest rocket t' build, and t' tradeoff betwixt total weight and balance for safe flight is more critical with this rocket than others. However, it is an interestin' and unusual design and looks cool in flight, arrr, me hearties, addin' an element o' excitment above me other rockets. I am surprised more Bomarc kits are nay offered by t' mainstream manufacturers. Blimey! Begad!
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