1/18 scale Tervamaki Engineering JT-9T autogyro

[Nick_Karatzides]

CHAPTER VI - Landing gear system construction

The single seat JT-9 and the tandem seating JT-9T, are available with tricycle landing gear system with a steerable nose wheel or a taildragger version too. For both types, the type of landing gear is based on the placement of the exact CG position, determined after complete weight calculations according the owner/pilot's personal needs. My 1/18 scale model is designed to be equiped with a tricycle landing gear system with a steerable nose wheel. An utility free-spinning tail wheel is also placed, to prevent any accidental damage on tail structure if the autogyro raise nose too high while in ground. Feel free to check the diagrams and images found into my first post of this project, back in page 1.

Using plastic card, sprue, metal wire, resin tires and brakes fit accurately to 1/18 scale diagrams and few unidentified parts found in the sparebox, I build a realistic looking 1/18 scale main landing gear system with absorbers and a steerable nose gear. I stole a nickel plated button from GF's favorite dress (hope she'll never find out where's the missing button or I'm in real trouble), placed it into a plastic tube piece, covered with with transparent plastic card & add some details to simulate the landing light in scale.

Yeah, yeah, yeah... I know! I am a button stealer, but let's admit it! We all prefer less buttons on female dresses.

[Kerber]

Oh, no, not again! 
I need more time to understand all of Your magic...and thnx for it !
Amazing !

[Nick_Karatzides]

CHAPTER VII - Canopy construction

The Jukka Tervamäki Engineering JT-9T autogyro canopy is made by bented and cold-formed 3mm polycarbonate sheet. The backwards sliding canopy of the single seat JT-9 version, offers the possibility to taxi and fly slowly with the canopy open, a benefit in a hot climate. The trainer / tandem seating JT-9T, has a side opening one piece canopy. Of course, canopy modifications can be done, according the autogyro owner's personal needs or desires.

I used styrene plastic card to form it as shown into following pictures to give the basic shape of the canopy. Then, a layer of polyester filler applied on the styrene. The specific polyester filler I used, comes with the proper catalyst which provides a solid rock build and approximately 3 to 5 minutes time window to form it into shape. I prefer to use epoxy putty or polyester filler with fiberglass grains for special purposes, 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 polyester 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 watch out. 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.

When the basic canopy shape made by styrene sheet, was fully covered by a a thin layer of polyester filler and had enough time to polymerize and get solid rock, I sand it with wet sandpaper to make the cast curved and shiny. To produce a thin-skinned canopy, the polyester part should be vacuum formed. As described into previous chapters, a transparent plastic sheet were pined on a wooden frame, preheated into electric oven and as soon as I noticed that it started drooping down, I vacuum formed it. The clear plastic nicely formed around the canopy cast following the curves & details as planed. Using an X-acto, I removed the formed canopy bubble from the transparent sheet and start adding details, such as canopy's frame. Few drops of cyanoacrylate glue applied on the right spots with great caution. Remember that CA glue does fog the transparent parts and this canopy would not be an exception - that's why I placed some very tiny drops of it, just on few spots.

[menestenasli]

This is one beautifully made landing gear!!! It's hard to believe it's scratch built! Can't wait to see it finished!

[Nick_Karatzides]

It's sad! Obviously, voodoo curses came from the unspeakable dirty Viper snake, got real and the final varnish finishes on the model suffered what the Americans call as FUBAR - F@cked Up Beyond All Recognition.

In brief words, the color layers popped and "cracked" everywhere on the model's surface, just before the final touch. For some mysterious reason, the color looked peeled off and an unexpected chipping (I would never succeed this by purpose) appeared! The scale modeling accidents committee is expected to investigate the possible reasons within following days, but unconfirmed sources report "pilot's error" - OK, I made a rookie's mistake, while using old colors or coat varnish. Meanwhile, the following actions took place:

• Garlic cloves were hanged across the workbench to keep away evil curses, vampires and "snakes" (or those who claim themselves as "snakes"),
  
• The scale model were covered with a thick layer of ModelStrip product, locked tightly in a plastic bag and left overnight to let the chemical work.

[Dada]

Oh, man, this is insane! Just kidding, great job so far. I really enjoy while reading your posts.
Keep up good work.

[zamorano]

This is unreal... Watching you doing this feels like watching those guys who free-climb skyscrapers. If there ever was anything qualified to be called extreme modeling, this is it.

[Nick_Karatzides]

                        

[Nick_Karatzides]

It's sad! Obviously, voodoo curses came from the unspeakable dirty Viper snake, got real and the final varnish finishes on the model suffered what the Americans call as FUBAR - F@cked Up Beyond All Recognition.

CHAPTER VIII - Live After Death

When I started building the model, I did not expect to present the CHAPTER VIII under this title. Bus as all the sad & bad situations in life, it was unexpected and accompanied by great frustration because suddenly I saw months effort to dissolve in only few minutes. The old colours (or bad white spirit solvent) that I used, have led to drying crack. Unfortunately, I ignored all the warning signs such as thick grains left by the white colour in which I primed the scale model before the final painting. Having as target to make this model alive again, just like Iron Maiden Eddie's Live After Death, I decided to try a full reset – after all, I had nothing to lose! The scale model was already FUBAR.

The following photos show the unsuccessful paint process. The problems appeared marked inside the red circles. Unfortunately, I have no photos of the model while looked completely written-off, because at that time I was not in a mood to take pictures!

ModelStrip, was the first thing came up as the most conventional solution to try paint removing. Following the instructions on the box, a generous stuff applied on the model, wrap it with airtight plastic bag to prevent drying and wait about 15 hours to let the chemical work. Opening the bag next day and checking the results, the colour (or rather the colour layers) were soft and could be removed by rubbing vigorously with an old toothbrush. Unfortunately, using the brush on some very delicate spots (even with careful use), had as result to break / or ruin a couple of plastic pieces. Moreover, the paint could not be removed through narrow points and difficult locations.

At this point and while I've already used all the ModelStrip material without being satisfied with the outcome, I decide to change tactics to something more unconventional, such as oven cleaner.

Following the product's directions as always, I sprayed the model with the material, wrap it with airtight plastic bag to prevent drying and wait about 15 hours to let the chemical work. Testing results next day, the oven cleaner failed no more than ModelStrip. I noticed that the colour could be removed but only when pressure and persistent rubbing with brush and that was prohibitive for some parts of the model. Not having another solution, I approached the most unconventional method and visit a science specialist - my local grocery store!

- Hey man! I need something really strong to clean up kitchen's oven?
- Really strong? Use this!

...and he gives me a dust covered 1lt plastic bottle found in an almost unreachable shelf. Reading the bottle's label, I found out that it contains sodium hydroxide also known as lye (corrosive alkaline substance) or caustic soda and is a caustic metallic base. It is used in many industries, mostly as a strong chemical base with chemical type NaOH.

- Are you sure that this will work? Are you sure that this is safe to use?
- Trust me. It's gonna clean up the kitchen's oven like a nuclear bomb!
- How much?
- 3.50 € . Take it or leave it.

Thinking about a possible failure, I filled a plastic bowl with the milky liquid contained in the bottle and threw all the model pieces inside. As long as the autogyro model was already FUBAR, I had nothing to loose to try. I sealed the bowl with a cover and leave the sodium hydroxide to act for 20-30 minutes while the instructions sets out to wipe the sodium hydroxide chemical liquid after 10 minutes. Opening the plastic bowl's cover, a nice surprise followed...

The truth is I was delighted! Styrene pieces simply and magically totally striped off the enamel colour layers! Absolutely success, without even apply brush cleaning! Amazing product - incredible grocer! Just because I couldn't believe it and I wanted to make sure that the colour striped off because of the sodium hydroxide chemical (and not the previous used ModelStrip product or the kitchen oven cleaner), I decide to experiment. I threw in a bowl, already filled with the chemical, a 1/18 scale female figure that I was about to convert for a future project. The specific 1/18 scale female figure, is made by Fast Women brand and can be found by clicking HERE). The results after just 15 minutes in the sodium hydroxide chemical - Perfect! The following pictures, show the "before" and the "after".

Keep in mind that the sodium hydroxide is (and thus should be considered) a strong caustic base. This means that:

• Throughout the impregnation of the model parts into sodium hydroxide, you should take all the necessary protective measures (like mentioned in the warnings on the bottle's label) and is certainly to use disposable surgical gloves made by latex and breathing mask with appropriate filters to protect against possible fumes.
  
• The colour stripped plastic parts must be rinsed with soft acid to neutralize the caustic base and produce salt and water. Dunking the colour striped parts in plastic container filled with cooking vinegar and then rinsing with plenty of lukewarm water, plastic is now safe to handle with bare hands.

Under the above "adventure" circumstances and considering that all these years dealing with the scale modeling I've tried many color striping methods (including ModelStrip, kitchen oven cleaners, blue alcohol, brake fluid, nitro laquer disolvent, etc), I think that sodium hydroxide NaOH is the best method so far, for the following reasons:

• Kitchen oven cleaners in spray canisters, can do the job, but they cost 3 - 4 € for a 300ml product in which also includes the propellant gas. On the other hand, the NaOH in liquid form is a pure substance, much less price, taking for 1lt bottle, which equals 3.3+ times more product! Using the liquid form NaOH (which you can fill a plastic bowl), you can sink several plastic pieces, same time!
  
• The brake fluid may be effective and remove paint, but it is not plastic friendly plastic and is likely to convert the scale model into a blob of molten plastic. It is clearly more expensive and as far it is highly toxic, flammable and hardly to manege, I will not recommended it for scale modeling use.
  
• Nitric acid laquer disolvent, could be a nice solution for metal figures paint striping, but it is not the best for the plastic. Just like the brake fluid, it does melt and damage plastic parts.

[Kerber]

Hm... Mr Musculo for oven is working fine, almost, but for me. Sometimes, even after 2-3 ours in a plastic bag...But, anyway, You have solved the problem successfully, and this is the point.
Keep modeling !
Cheers!

[Nick_Karatzides]

Hm... Mr Musculo for oven is working fine, almost, but for me. Sometimes, even after 2-3 ours in a plastic bag...But, anyway, You have solved the problem successfully, and this is the point.

Kitchen oven cleaner products found into spray cans such as the Mr Musculo you mentioned, can do the job but cost too much because you pay about 3 or 4€ for a 300ml spray canister which does not contain only NaOH but propellant gas too. On the other hand, if you buy pure NaOH in liquid form, you pay the same price and you get 1lt (3.3+ times more product) bottle, which you can fill into a plastic bowl and sink in it as more plastic pieces as you like, same time! The best part is that the NaOH stuff works maximum in less time, because as long as the plastic parts are sunk into NaOH and remain fully covered by the chemical, you do not need to wait hours and you do not need to apply brushing to remove paint.

Under the above "adventure" circumstances and considering that all these years dealing with the scale modeling I've tried many color striping methods (including ModelStrip, kitchen oven cleaners, blue alcohol, brake fluid, nitro laquer disolvent, etc), I think that sodium hydroxide NaOH is the best method so far, for the following reasons:

• Kitchen oven cleaners in spray canisters, can do the job, but they cost 3 - 4 € for a 300ml product in which also includes the propellant gas. On the other hand, the NaOH in liquid form is a pure substance, much less price, taking for 1lt bottle, which equals 3.3+ times more product! Using the liquid form NaOH (which you can fill a plastic bowl), you can sink several plastic pieces, same time!
  
• The brake fluid may be effective and remove paint, but it is not plastic friendly plastic and is likely to convert the scale model into a blob of molten plastic. It is clearly more expensive and as far it is highly toxic, flammable and hardly to manege, I will not recommended it for scale modeling use.
  
• Nitric acid laquer disolvent, could be a nice solution for metal figures paint striping, but it is not the best for the plastic. Just like the brake fluid, it does melt and damage plastic parts.

[Nick_Karatzides]

CHAPTER IX - Applying paint, wash & weather effects

Model parts were washed with liquid soap and warm water to disappear leaving oil traces, fingertips etc and then sprayed with light grey primer.

The first base color layer sprayed with no problem and then a second white color layer applied on specific spots to simulate enlightened areas. Then, using very diluted acrylic color Vallejo paint, 2-3 extra thin layers were sprayed throughout, until the result become realistic and simulate correctly the enlightened areas.

As soon as the previous layers of acrylic Vallejo paint and gloss coat varnish dried, I placed small slips of paper between the frame and the sheet of the fuselage, to protect the red colour that was already applied and dried. Next, I masked areas not to be painted using the adhesive Tamiya tape and sprayed with the interior green colour.

[Nick_Karatzides]

After the interior colour dried, the slips of paper and adhesive masking tape removed and minor corrections were made in 1-2 spots with a fine brush. The result was sprayed with gloss varnish, to apply washing on certain points.

[Nick_Karatzides]

The steps are slow, but I prefer steady progress rather than hastily. Unfortunately, the problems are not missed. Although I do not think myself as awkward, after the incident with the (voluntarily flying) autogyro model scaffolding under my sleeve and threw (launched to be precise) on its own initiative, brought about 4 or 5 spin turns and finally abnormal landed about 5 feet away and 3 feet lower, I begin to believe that this model has been seriously voodoo curses. Despite the delicate structure of the fuselage, the use of CA glue and maybe a mirracle, were the main reasons that the model escaped having suffered only a broken landing gear, scratchbuilt again.

After the scale model was masked & sprayed with primary colors as described above, the same methodology followed for the canopy, scratchbuilt by transparent plastic on a vacuum former. After the acrylic paint and mat enamel coat dried, I removed the masking tape and I saw the following:

The masking tape that I had used, had left noticeable marks on the transparent part of the canopy - something that had never done before! Being sure now that this scale model is indeed cursed, I dropped by the local grocery store around the corner from where I returned with few garlic cloves. Not having a similar experience before and fearing that if I try to clean the masking tape glue marks using White Spirit will make the things worse with a huge dull hood, I tried to rub the clear plastic part with alcohol which although more friendly to transparent plastics, had to pass crash test first. Dipping a cotton swab in alcohol and water solution and vigorously rubbing the hood, the masking tape glue marks, finally removed as if it was gum.

With my heart beating on normal levels again and using airbrush, light tones of basic colours and shades of sand sprayed at low pressure to represent the weathering and dusting on LG and the lower part of airframe. After a satisfactory weathering result, the scale model was sprayed with mat enamel coat. I left it 24 hours to dry and the individual parts of the scale model were test assembled (no glue), so that the autogyro model start to look like a united construction and please the eye.

Having now left the last part of the assembly of the individual already dyed parts of the model, such as the rotor blades, the cockpit flight & engine controls, the cables, the seat belts and other necessary details, I begin to hope that perhaps this model might be ready very soon.

[oddball]

Highly detailed work! You have lot of patience,and you have a very steady hand. Personally, i don't like preshading so exposed but that is a matter of taste. Anyways, very good work!