Nick_Karatzides

About 45 minutes after laquer thinner resolvent and Humbrol putty liquid mixture applied with brush on the skeleton to fill the tiny gaps between the connections, it looked to be fully dry and safe to sand it. As soon as that was done, the skeleton was hanged by a string and airbrushed with enamel mat white color as a base coat. Cockpit floor, wheels etc made while waiting the putty to dry, were also spayed with base coat. Gdy tylko ca³o¶æ szpachli wysch³a i jej nadmiar zosta³ wyszlifowany, podwiesi³em ramê na sznurkach i nanios³em aerografem bia³± farbê olejn± jako kolor bazowy. Pod³oga i inne rzeczy, robione w czasie gdy sch³a szpachla, zosta³y równie¿ pomalowane.

CHAPTER I - Basic airframe skeleton construction Rozdzia³ I - budowa podstawowego szkieletu Following the 1/18 scale printed diagrams and using just a sharp blade and ZAP superglue, it took about 60 minutes to build the basic airframe skeleton. The tiny gaps between the skeleton connections, were filled with Humbrol modeling putty, applied with an old brush. In order to make the putty liquid and let it spread naturally and fill the tiny gaps, I mixed it with laquer thinner. Because the laquer thinner is volatile, the liquid putty mixture took about 45 minutes to get fully dry and be safe to sand - carefully ofcourse. If you follow this method, be sure that you mix the laquer thinner and the modeling putty into a metal or glass plate / canister, because the most plastic materials cannot stand it and melt. For this reason, keep in mind to use just the essential laquer thinner quantity, in order to remain the mixture in liquid form, as it is presented at the following pictures. Bazuj±c na planach, przy u¿yciu ostrego no¿yka i superglue, potrzebowa³em oko³o 60 minut na budowê podstawowego szkieletu ramy. Malutkie szparki na ³±czeniach odcinków wype³ni³em szpachlówk± Humbrola przy u¿yciu starego pêdzla. Aby ja rozcieñczyæ, dziêki czemu mog³a penetrowaæ szczeliny, doda³em rozcieñczalnika (np. nitro, dop. t³umacza ). Poniewa¿ taki rozcieñczalnik jest bardzo lotny, po 45 minutach mog³em spokojnie szlifowaæ ³±czenia - ostro¿nie oczywi¶cie. Je¶li chcecie u¿ywaæ tej metody, do mieszania szpachlówki i nitro u¿ywajcie metalowego lub szklanego pojemniczka - wiêkszo¶æ plastikowych nie wytrzymuje tej mieszanki i siê rozpuszcza. Wa¿ne s± proporcje w dodawaniu rozcieñczalnika aby utrzymaæ miksturê w p³ynnej postaci - tak jak na zdjêciach.

1/18 scale Tervamaki Engineering JT-9T autogyro scratchbuild Having tried my (suicidal) virgin 40 minutes flight experience with a friend's homemade autogyro during my summer holidays with him on flight controls and me on the passenger's backseat, I can surely say that you really feel like a bird, sensing even the slightest airwave or gravity accelerating change straight in your floating stomach. As soon as I safely stepped on solid ground again and returned back home in one piece, I felt the iresistable temptation to try a 1/18 scale autogyro scratchbuild. The following article is to describe step by step the 1/18 scale Tervamaki Engineering JT-9T autogyro, designed by Mr. Jukka Tervamaki and currently flying by ultralight aviators around the world keeping the Mad Max II GyroCaptain's (aka Road Warrior) spirit alive! Po odbyciu 40 minut mojego dziewiczego, samobójczego lotu na wykonanym przez mojego przyjaciela autogyro, podczas wakacji, z nim za sterami i ze mn± na fotelu pasa¿era, mogê z pewno¶ci± powiedzieæ, ¿e czu³em siê jak ptak, wyczuwaj±c najl¿ejszy strumieñ powietrza, zmianê przy¶pieszenia - prosto w moim ¿o³±dku. Jak tylko stan±³em ponownie na ziemi i wróci³em do domu w jednym kawa³ku, poczu³em nieodpart± pokusê na spróbowanie budowy autogyro w skali 1/18 od podstaw. Poni¿szy artyku³ opisuje krok po kroku budowê Tervamaki Engineering JT-9T autogyro, zaprojektowanego przez Mr. Jukka Tervamaki, a obecnie u¿ywany przez lotników klasy ultralekkiej na ca³ym ¶wiecie - utrzymuj±c legendê GyroCapitan'a Mad Max II (znanego jako Road Warrior) przy ¿yciu! The basic JT-9 autogyro concept is about a tractor gyro design with good aesthetics and performance with fairly low power. A 1.7 m diameter 2-blades propeller is powered by HKS 700 or Hexadyne Aviation P60 diesel engines, both delivering about of 65 hp at 2400 rpm. The fuselage of the JT-9 is of normal steel tube construction covered with dacron fabric. On the other hand, the JT-9B model is equipped with an electric motor instead of a diesel engine, with only difference the 3-blades propeller and wider front cover to house the battery packs onto both sides of the fuselage. The model I'll try to build in 1/18 scale, is the JT-9T model, which is the two-seat trainer (as for the "T") model. Podstawow± ide± JT-9 jest dobrze wygl±daj±cy silnik, o dobrej wydajno¶ci i stosunkowo ma³ej mocy. Proste ¶mig³o (1.7 m ¶rednicy) jest zasilane silnikiem HKS 700 albo Hexadyne Aviation P60, oba diesle, dostarczaj±ce oko³o 65 koni przy 2400 obrotach. Konstrukcja kad³uba opiera siê na stalowych rurkach, obci±gniêtych tkanin± dacron (rodzaj polysteru). Model JT-9B ró¿ni siê tym, ¿e ma silnik elektryczny, trójostrzowy wirnik, i baterie do silnika w poszerzonym kad³ubie. Model jaki postaram siê odwzorowaæ, to JT-9T - model dwumiejscowy, treningowy. Having the basic blueprint line diagrams in hand, it was easy to convert them into 1/18 scale with a photocopier and I began the scale model building, starting from zero using 0.25mm styrene card and plastic sprue. To make the construction look more interesting, I decide to build the model in a way that airframe should look like cutaway side opened and let cockpit detail be easily observed. Maj±c pod rêkê podstawowe plany, przeskalowa³em je do skali 1/18 na kserze. I rozpocz±³em budowê od zera, u¿ywaj±c p³ytek plastikowych 1/4mm i plastikowych rurek. Aby uatrakcyjniæ dzie³o, postanowi³em zrobiæ model z wyciêt± czê¶ci± poszycia, tak aby kokpit móg³ byæ ³atwo podziwiany.

Found into my old sparebox, a cracked & damaged 1/48 scale fire extinguisher could be also be upgraded to become the metal oval shaped tank found into the main landing gear bay, known as the Halon 1301 (also known as Bromotrifluoromethane CBrF3, which is a an organic halide to provide fuel cell inerting to protect the fuel system from explosions due to combat threats) reservoir. Filling the gap with epoxy cream, sticking it on a nail and spin it with the Dremel tool against different types of sandpapers was enough to make it look like the real one.

Starting to place cables, actuators, fractional DC motors, hydraulic lines, securing hooks & stuff into the model's main landing gear bay. It may look quite empty now, but everything will be in place and look realistic as the project continues. I used hair thin copper wire cut off from a simple electric cable to bond plastic spue together, to simulate the cable braids found into an F-16's main landing gear bay. The cables and hydraulic lines are placed carefully according closeup pictures of the real gear bay.

The main landing gear possessors basic lines were copied from the T.O manual, lined out with green ink marker and later cut 'n' drilled from white plastic card. Blueprint copies enlarged to 1/18 scale, were used to cut the possessors on exact shape & size and later set into place.

The air intake case, connected with the lower surface with ZAP cyanoacrylate super glue and the huge (approximately 2mm wide) gaps were filled with epoxy cream. I prefer to use epoxy putty (or polyester filler with fiberglass grains for special purposes) instead of normal scale modeling putty, to close gaps or build new items, because: It becomes solid rock within only few minutes or seconds, it does not shrink and does not crack after months or years, you can pour to any shape that you want but you need to work fast because as soon as you mix it with catalyst cream approx 5%, you have limited time before becoming solid rock, you can also put additional layers of epoxy or polyester filler to build up, you can sand it, you can drill it, you can use any type of scale modeling glue, any type of primer or enamel / acrylic paint on it with no problem, can be purchased at any good crafts store into 250ml, 500ml, 1lt (comes with a tube of catalyst hardener) or bigger canisters and if you can't find it, fear not and try your local decent hardware store and finally... it is cheaper than dirt - estimated prices are £3 to £10 depending the canister size, the quality, if contains fiberglass grains for maximum strength etc. Keep in mind that the chemical reaction after mixing the filler with the catalyst hardener, produces some heat that possibly effect on thin plastic parts, so test it first before try it on your scale model. I don’t think that the produced heat is more than Fahrenheit 110, but better watchout. Remember that epoxy materials are dangerous when breath or shallow and could result skin, eyes or lungs problems or even cancer when used for long period with no precaution measures. Always keep in mind, that a powerful vacuum system to suck away the epoxy dust should be used all time to keep the workbench area clean while sanding or milling epoxy or resin materials. Using an issued breathing mask and a pair of surgery latex gloves to prevent dust contact with lungs and fingers while sanding or milling epoxy, is also an important matter that you should seriously take care of! My recommendation is to also wear an overall working suit (as I do) to keep your clothes dust free while sanding epoxy. Some people might find it too much, but I wouldn't like to bring epoxy dust & grains from my work bench into living room and my beloved.

Using 0.75mm drill, a single hole opened on the air intake tube, to later host a pitot sensor which is normally can be found just before the engine's intake fan. This drilling should be done now, before connecting the main landing gear bay construction with lower part of F-16's surface and the pitot sensor will be placed later.

CHAPTER IV - Main landing gear bay construction The main landing gear bay is one of the most complex areas on this 1/18 scale model. I did the dimension calculations, sand the outer surface of the air intake tube carefully, cut pieces of plastic card as required and placed them to start building the bay.

The F-16's hot air exhaust of the ECS (Environment Condition System) comes in two different shapes. The old A/B types come with small cover. Here is the way it is covered nowdays on newest Block 52s F-16C/D. The basic shape of the ECS cover made by plastic card and the air exhaust detail will be added later.

When the chalk wash dried, I rubbed off the high spots with a slightly damp dry (not wet) Q-Tip cotton swab (Kleenex papers can be also used) and I wiped the dark color from the areas should be light colored. The high spots were cleaned to the basic finish and the low spots were left black. I did the chalk wash on the inner embossed detail on the afterburner's area in about 15 minutes which makes it a very quick and effective technique. You can also read about this into Steve Bamford's article, by clicking HERE. Some of the wash mixture is re-applied and the wash being wiped completely out of the narrow points. If you follow this method, it is adviced to not rinse out the wash container till you are finished this job. You will probably be touching up certain spots a few times, so it helps if you're not mixing up a new chalk mixture each time because you kept cleaning out your container of the chalk wash mixture. I repeated the the wash process with lighter colors where needed. Using micro cotton batons found into cosmetic shop for less than 1£, I applied some lighter colors such as yellow, white, sand, brown, burned iron etc & also black chalk pastel powder on the inner embossed detail on the afterburner's area, to make it look weathered and extensively used. I repeated the weathering process until it satisfied me and finally I sprayed a clear coat to seal the chalk powder in place.

Once the chalk is fully dissolved into the water/soap mixture it is time to "paint" this mixture on the inner embossed detail on the afterburner's area. "Painting" the mixture is simple - just apply it anywhere it is needed to darken recessed detail. The mixture can be applied carelessly, because any mistakes can be completely removed and redone.

As I personally believe that following simple techniques and sometimes unconventional methods, result in superior effects, I usually do not use enamel or acrylic paint to wash, because I feel risky when applying the paint mixture and let it run. I prefer an easier technique that can be undone if the results are poor - that makes it the perfect technique. I use hard chalk pastels to wash (NOT oil pastels). The hard chalk pastels, look like a teacher would use on the blackboard in school. Do not use the soft oil pastels that artist use to draw on paper. The hard chalk pastels are easy to find in a variety of colors into your local art store or maybe Wal-Mart if in US or ASDA if in UK. To do the wash, I use an X-acto knife, a small metal or plastic container, an old brush, dish washing soap and a bit of water. Begin by scraping some chalk powder from the side of the chalk pastel stick, carefully put this chalk powder into the small container and add a tiny amount of water and stir. It is important to add a tiny amount of water in order to make the mixture look like mud - not like soup! For this reason, I use a syringe to add just few drops on the hard chalk pastel powder and I stir using the old brush. Because the chalk powder doesn't mix well with the water, a drop of dish washing soap is needed to break the surface tension of the water and also acts as a "glue" to help the chalk powder stick to the model.

After placing the cable tape into the base cylinder without spreading clue, I pressed it against the plastic using my thumb, to eliminate any possible bumps or waves that may appeared. Thank to accurate calculations the cable tape ends, came exactly one against the other, almost in a perfect facing touch. To secure the cable tape in this place, I dropped cyanoacrylate clue through the opened holes on plastic.

Having a couple of different methods in mind to simulate in scale the inner embossed detail on the afterburner's area, but knowing that the following method is much accurate to scale and easier to re-do if something goes wrong, I tried a visit into my local PC store and searched for a cable tape used into PCs to connect the motherboard with the HDs or CD/DVDs etc and transfer data between them. I found a plenty of PC cable tapes, but I finally got one with intense embossed detail between the cable lines. After calculating the base cylinder's inner circumference, I cut the brand new cable tape on exact length, sprayed it with light gray base coat and placed it carefully into the cylinder, trying to avoid folding marks on the cable tape surface.

CHAPTER III - Engine's afterburner area construction Starting to work behind the engine's last stage blades and the afterburner's spoked frame, I had to simulate in scale the inner embossed detail on the afterburner's area. Following the exact blueprint plans of the T.O service manual used for the real F-16 and after converting numbers to 1/18 scale, I did calculate the AB area dimensions, cut a piece of plastic card, fold it to cylinder and reinforce it externally with plastic bands, to ensure that it'll keep in shape. This cylinder is the base to host the inner embossed detail on the afterburner's area. As soon as the base cylinder was ready, I opened randomly more than 30 holes, using a 2mm drill - the reason will be explained into following lines.

As it is well known, the Block 52 F-16s (using the Pratt & Whitney F100-PW 229 afterburning turbofan engine) air intake shapes are not the same with older "big mouth" F-16 versions such as Block 30 and Block 50 (using the General Electric F110-GE 100 afterburning turbofan engine) also used by the Hellenic Air Force Squadrons. The newest Block 52s have a larger nose tire which required the intake to be reshaped to accomodate the new tires size. For this reason, the Block 52 F-16's newer air intake have a noticeable bump about 4 feet in on the lower surface.

Using plastic card, I formed a 1 inch wide ring and placed it to the air intake tube's end, in order to fit perfectly the Pratt & Whitney F100 turbofan engine's 1st stage blade fans structure, which displayed earlier. Epoxy putty filled the gaps and formed the tube's end diameter to a perfect circle.

After proper sanding, the inner air intake tube looks OK to me

By the time all the thinned plaster, dissolved cardboard pieces and cloth net remains were removed, the tube was sanded properly, washed and attached by using cyanoacrylate glue on the F-16 lower fuselage "mouth" housing. Epoxy putty and polyester filler used to close the huge gaps.

Staying underwater for few hours, waiting for the enclosed cast made by cardboard and plaster to get decomposed and become soft, mixed pieces of cloth net, thinned plaster and moistened cardboard were removed with caution.

Johnson's baby oil (thin layers of vaseline based mixtures can be used also) brushed as a segregative material for later purpose and generous quantities of polyester filler applied on the plaster cast. The specific polyester filler I used, is enriched with fiberglass grains to enforce the final construction. The filler should be always used with the proper catalyst which provides a solid rock build and approximately 5 to 10 minutes time window to form it into shape. When the plaster cast used as a "negative image" of the air intake tube, was fully covered with a 3-4 mm thick layer of polyester filler enriched with fiberglass grains and had enough time to polymerize and get solid rock, it was sunk into water and stayed wet overnight, in order to let the enclosed cast made by cardboard and plaster get moistened and decomposed.

Materials like plaster, start as a dry powder that is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after drying, and can be easily manipulated with metal tools or even sandpaper. These characteristics make plaster suitable for a finishing, rather than a load-bearing material and that exactly is what I'm looking for on this air intake tube construction. Keep in mind that adding salt into wet plaster mixture, reduce the plaster's hardening time and adding vinegar into wet plaster mixture, extend the plaster's hardening time. When the first layer of thinned plaster applied on the net was dry and hard enough to hold the basic spine made by cardboard, a second thin layer of plaster was applied to form the curves of the air intake tube, following the lines of the pre-cutting cardboard. The basic idea, is to keep this plaster cast hollow, accurate on scale and as thin as possible trying not to apply extra stuff where is no needed. When the plaster cast was dry and hardened, tiny quantities of modeling putty added to close minor scratches and pores on plaster cast surface, brushed with water based clue, painted in black color, dry sanded and finally sprayed overall with gloss shiny coat.

Having the official F-16 Block 52 blueprints copied from the T.O manual, I got the exact dimensions of the air intake tube, print them down on a cutaway image and using scissor and simple cardboard, I create a the "negative image" of the air intake tube, basic spine. As soon as the spine made by cardboard was set on a straight line, it was wrapped around with a cloth net found into the 1st aid kit. Small quantities of plaster, highly thinned with water, applied on the cloth net with a brush, to build the first layer of a hollow plaster cast, which would become the "negative image" of the air intake tube.

CHAPTER II - Air intake tube construction Because the main BBI - Elite Force kit was very poor on detail and had the air intake tube sealed, I had to first open the air intake by cutting the plastic and then build from scratch the approximately 30cm long tube, leading to the engine's 1st stage blades described in detail into previous Chapter I. Just because the F-16's air intake tube is not just a straight line tube, the idea of scale building with plastic card was rejected from the first moment. If you notice, the F-16's air intake tube is curved in both X and Y axes while heading to the engine's 1st stage blades. Source: http://www.f-16.net For this reason, I decide that a "negative image" cast of the air intake tube should be made and build the tube model using this cast, with two available & different methods: The 1st method is based on a solid rock (made by balsa, epoxy filler, plastic etc) "negative image" cast of the air intake tube on which I would try to vacum form some air intake tube "half" parts (left-right or upper-lower). Some very thin (and fragile too) plastic parts could be produced, but with doubtful contact between the two "halfs". For sure, the tube "halfs" would leave visible contact line marks across the construction, that should be filled with putty and carefully sanded on a fragile and extra thin plastic material. The 2nd method is based on a deliberately fragile and hollow "negative image" cast made by soft materials (such as plaster and cardboard), that could easily be decomposed and removed after sinking into water. I decide to follow the second method, knowing that I had only one shot to try, with no mistakes allowed, considering that the cast would be destroyed after use, but I could have one-piece tube as a result, without any marks or lines inside the tube and also avoid unneccessary sanding with doubtful results. By selecting the second way, which was more desired and realistic for me, I finally produced one solid rock one-piece air intake tube, very accurate on scale, following exactly the real air intake tube curves and present to fellow modelers a mighty unconventional way of scale building to keep in their mind for any future projects of their own. That's why, I present the project with step-by-step pictures, to provide any possible help to understand how did it. After all, I believe that scale modeling is not just cutting plastic parts straight from the kit box or maybe use some resin accessories already checked to fit perfect into models, but combining arts, skills, techniques and finally use our brain to invent new methods in order to have a realistic result.