1/18 scale Bölkow Bo-102 Helitrainer scratchbuild model

DUSTER

you did notice you left the battery switch on and have drainded the battery ---didn't you?

Nick

Thank you once again for shareing your fine work.

I am in aw of your skills as a model maker. 

 p.s. you did notice you left the battery switch on and have drainded the battery ---didn't you?

just outstanding work Nick  

and great tips all along the wip

I almost forgot to build the instructor’s bicycle type seat in which he sits, next to the student pilot. Using plasticine, I made an image cast of how I would like seat’s surface to look like. I only had to push the material gently with fingers and got the desired shape - in fact, the process took less than 5 seconds.

Using a small amount of Milliput putty, I made a small ball, dust it with talcum powder and pressed it against the working bench with a roller until it becomes as thin as could get. The use of talcum powder is necessary to avoid Milliput sticking on roller or fingers and get easier to handle without tearing to pieces.

When the Milliput was pretty thin, I lifted it and place it on the plasticine image cast I made earlier, to let it follow the shape and curves of the seat. Using an old wet brush, I let few drops of water on the Milliput sheet, to make it softer and easier to follow the seat shape and left it overnight to get harden. Of course, the same technique can be also used to build blankets, truck covers, etc.

I left the Milliput overnight to get polymerized. As soon as it was got harden, I removed the plasticine image cast and cut the seat, as shown into the following pictures.

Using airbrush, basic blue colour and shades of sand & rusty brown tones sprayed at low pressure to represent the weathering and dusting on the seat and the lower part of the landing pad with supporting base. After a satisfactory weathering result, the scale model was sprayed with mat enamel coat and left 24 hours to dry.

CHAPTER X - Clear canopy installation on bubble cabin

The Bö-102’s cabin and one-piece glass bubble canopy, offers wide visibility for the student pilot. The absence of side doors is a benefit in a hot climate and also provides better vocal communication with trainer who sits nest to student pilot. Of course, canopy modifications can be done, as seen Bö-102s with total absence of glass canopy. As written and described into previous “CHAPTER” I, the basic shape of the thin-skinned, right-to-scale bubble typed canopy, was made by vacuum forming 1mm clear polycarbonate sheet, on a solid rock one-piece image cast made of modeling clay and additional layers of epoxy putty & polyester filler with fiberglass grains. To do so, the clear 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 sheet nicely formed around the canopy cast following the curves & details as planed. Using an X-acto knife, I removed the formed canopy bubble from the transparent sheet and start adding details, such as canopy's frame.

The clear canopy frame was made by 1mm masking tape. Few drops of CA super glue applied on the right spots with great caution. Remember that CA super 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 to secure the installation.

After placing the clear canopy on cabin and adding few tiny drops of CA super glue just on few spots to secure the installation, small amounts of Squadron MMD green putty filled tiny gaps. Later, the green putty overages sanded lightly and the cabin prepared for airbrushing. The cabin was painted using the Life Color UA025 Light Gull Grey FS36440 acrylic paint and later the lower part was dusted by airbrushing a very light layer of Life Color LC37 Matt Burnt Umber FS3004 acrylic paint.

I found nice idea to place the Bö-102 Helitrainer on a display base, simulating a concrete ground area. The idea was to establish the picture of an abandoned small airfield in Vlotho, where the Helitrainer used to rest for decades till found and finally donated to the Hubschraubermuseum helicopter museum in Bückeburg, Germany. The museum workshop team, managed to restore it and display it as on of these experimental helicopter training devices. From my local store, I bought a 20x30cm polished wooden picture frame.

I add some grams of plaster powder and few drops of water with a syringe into a soft rubber cup to make the right mixture. 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 this characteristic make plaster suitable for the job. 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 picture frame, a glass were pushed against the plaster to form a flat basic strong cast. The basic idea, is to produce a totally flat cast and later add some detail or apply extra stuff where is needed.

I left it few hours to get harden in order to be sure that the cast wouldn't break when I would try to cut it into desired shape. Meanwhile, I took the soft rubber cup which I used to make the plaster mixture, squized it to break the last hardened plaster left inside, so it would be easier for me to clean it afterwards and prepare it for any future mix. That's the reason this soft rubber cup were used for.

As soon as the plaster cast got harden, cut into shape and the concrete plaques were lined with a scriber, I used my airbrush to paint it. After the polished wooden frame was covered with masking tape, three different acrylic paint layers were applied on the plaster surface. First, mat black colour covered the area and then a light grey applied with airbrush, spraying in almost zero degrees angle, to let the darker areas between the concrete plaques remain naturally dark. The corner was paint with earth tones and as soon as the acrylic colours dried, I tried some drybrushing on selected spots using sand tones.

As for he grass & plants, I used different colors of static grass from my local hobby shop, empty them into a plastic box and make a mixture.

Water based white glue for wood, which becomes transparent when it dries, is just the right for the job. So, I opened a 500gr canister bought for 2€ only, pick a small quantity, add just few drops of water with a syringe into a small metal container to make the right mixture and finally I applied on the desired areas to be filled with grass & plants, using a wet brush. Because the mixture is enriched with water based glue, it is easy to correct possible mistakes.

As soon as the result was OK, I sprayed over with Humbrol enamel mat coat, to seal the paint and grass, so far. I left it overnight and as soon as the enamel mat coat dried, I add very few light & dust effects with chalk dust and pigments.

great progress on the non-kit and magnific tutorial

Lifecolor acrylics, long time not use , why italian writings? you order colors from here? 

Dark brownish pigments & chalk powder shades, dissolved in water and spread in selected engine block spots gave a better look. When satisfied with the result, I began the tail boom painting process. To do so, I used the Life Color UA140 Yellow RLM 04 FS33538 colour which is actually the colour found into the official Bölkow’s technical order manual. Paint applied over 2-3 very diluted (almost pure water) thin layers, one after another, using a fine brush, keeping in mind that leaving paint marks should be avoided.

Usually, there are two available options for a scale modeler, to apply paint on a model:

• Paint the individual parts first and assemble the scale model later and
• Assemble the scale model parts first and paint the overall built model later.

While building this Bölkow Bö-102 Helitrainer scale model project, the first option seemed as more appropriate and would make my job easy. Unfortunately, I had to follow the second option – and that was not the only bad news. Building first and painting later, would be more difficult and would take much longer, but the reason I chose first to assemble most of parts and paint later, is because most of the Bölkow Bö-102 Helitrainer scale model’s airframe consists of a tail boom structure, in which contained the Hirth 3-cylinder / 2-stroke 40hp ILO L3X375 piston engine, the transmission components, the cable wiring etc that could not be masked without causing any damage. It could be very difficult – maybe impossible - to airbrush for example the tail boom and manage to leave the interior details remain unaffected by the painting same time. Here comes the bad news: Tail boom structure would be painted by using fine brush and lot of patience to avoid leaving any brushing marks that would be clearly visible on such a big scale as the 1/18 is.

After preparing the engine’s basic elements, connecting electric cables and oil or fuel lines, I airbrushed the engine block with Life Color LC24 Matt Aluminium FS37178 acrylic paint as a base coat and apply darker enamel mixtures using the Humbrol #27001, #27002, #27003 metal cote paint and finally add some Mr Metal Color #212 Iron on the engine and let about 24hrs to dry before trying dark brown and black washes.

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, looks 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 colours into your local art store or maybe Wal-Mart if in US or ASDA if in UK.

To do the wash, I use an blade, a small metal or plastic container, an old toothbrush, 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.

Once the chalk is fully dissolved into the water/soap mixture it is time to “paint” this mixture onto the model's engine. “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. Once 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 colour from the areas should be light & shinny. The high spots were cleaned to the bare metal finish and the low spots were left black. I did the chalk wash on the engine in under 30 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. As soon as I paint the electric cables, the oil or fuel lines etc, I repeated the wash process with lighter colours where needed. Using micro cotton batons found into cosmetic shop for less than 1£, I applied some brown chalk pastel powder on the engine's chrome exhaust, to make it look overheated. I repeated the weathering process until it satisfied me and finally I sprayed a Humbrol clear coat to seal the chalk powder on the engine.

well done

It’s been a long time since the last update, isn’t it? Well, I will not try to justify myself with cheap excuses. I’ve been so lazy the past few weeks and neglected the Bölkow Bö-102 Helitrainer project. Otherwise, I could possibly put the blame on anything but me, put the blame on the Mediterranean sun makes the summer last longer, put the blame on the planets spinning around the universe causing horoscope zodiac turbulences, put the blame on the Willie Coyote for keep failing to catch the Roadrunner, etc.

That would sound like a cheap excuse, wouldn’t it?

Some additional details were added to the fuel tank canisters. The left side fuel tank, was placed on the receiver base and strapped with hoops & tensioners to keep in place, while the right side fuel tank is to be placed on the ground, with the filler cap opened, simulating maintenance procedure. Finally, the landing pad base supports, built using balsa wood slats.

Nick

Great how-to for  vacuum forming

Glad you have a summer time off.

the last picture is Amazing! looks cool and inviteing- can almost hear the water lapping on the shore.

Looking forward to seeing  your work  when you return in the...

Each fuel tank, is placed on metal plate / receiver base and secured in place by hoops and tensioners, as seen into the following picture.

In order to reproduce, these metal plate / receiver bases, I tried vacuum forming. Because I was planning to use smaller wooden frame to secure the styrene (the pieces to be vacuum formed are small and there is no need to spend big styrene sheet), I had to close the outer holes on the hardboard high-density fibreboard plate. To do so, I cut a plastic bag in shape and covered as required the desired area.

The twin fuel tanks, wedged halfway into plasticine and placed on the vacuum former plate to form the fuel tanks receivers.

I pinned a styrene plastic sheet on the wooden frame, insert it into the preheated electric oven as described before and as soon as I noticed that the plastic got warm enough and started drooping down, I removed it from the oven and thrown the sheet on the vacuum former plate, while the vacuum cleaner was already plugged & switched on. This procedure may take some practice and sometimes a mould tips over or the plastic won’t form properly over the mould (folding around edges). This is also the part where I should warn you that you can burn your fingers - I highly recommend Nomex Aramid flame resistant MilSpec gloves, which I personally use for the job. I buy large plastic styrene 50x30cm sheets for 0.5€ to 1.5€ each (depending width), not the more expensive styrene by Evergreen. When an attempt fails, I usually throw the sheet back in the oven and start again. Once you have the machine, you can make all kinds of things. You can make a lot of aircraft wings, airframe, panels etc out of a sheet like that. You can make the master moulds from balsa wood, epoxy, polyester etc and the parts you make depend on how accurate the master moulds are. The moulds must be as accurate and detailed as necessary to achieve the results you are after.

The plastic nicely formed around the fuel tanks moulds and here is how it looks like.

Using a new Nr 11 stainless steel surgical blade, I removed the formed pieces from the styrene sheet. The yellow stuff appears in the picture, is plasticine surplus - the plasticine used to secure the twin epoxy tanks on the vacumm former plate and caged into vacuum formed plastic sheet. Later, these two receiver bases will be sanded as required and some details such as securing hoops and tensioners to keep the twin fuel tanks in place will be added.

It’s mid July already! It’s time to enjoy a nice cool summer and recharge batteries while drinking icy mojitos by the beach. I’ll meet all of you right after my summer holidays on sunny Cyprus island and I promise all the latest WIP pictures & updates when I’ll be back. I wish you best summer and happy holidays.

I think you are referring to the section shown in the following picture. Right?

Well, simply buy a cheap analog hand-winding alarm watch (the cheaper, the better) smash it with a hammer or if you're patient enough, carefully unscrew the casing. You will be amazed with the quantity of items you can use as spare parts. The part you are interested into, found into my spare box and as far as I remember is one of the unidentified little shiny things came out of an old & cheaper than dirt analog hand-winding alarm watch casing.

Nick, once again you combine great craftsmanship with good ideas and important safety advice.

(your relationship advice is also important to those who need it )

Enjoyed your JT-9T autogyro and this is as good.

**********************************

Oh and don't forget to oil (virgin olive in your case) the bearings in the tail rotor assy. - you DID make individual bearings and bearing races didn't you?

The twin epoxy blocks got trimmed and sanded gradually to shape into the desired form and look realistic Helitrainer fuel tanks into scale. Later, few thin layers of liquid scale modelling filler applied over the epoxy to smooth out small imperfections and be seen as a comprehensive outcome.

When it looked OK to me, it was sprayed over with Humbrol acrylic primer to spot any mistakes and be ready for final paint. Each part was fit tested to ensure that anything can be combined together as one piece.

jt-9t also great piece! 

keep on posting, lots of great ideas from you

For my 1/18 scale project, I chose to recreate the wheeled version, which seemed to me as more interesting than others. As you can see in the following pictures, the landing pad & supporting base was built by styrene plastic, sprue, metal wire and glued with CA glue and Humbrol liquid poly.

bsyamato

This is one of best scratchbild i see here and good tutorial too!! also show how the cheaper way can be great. the subject is really strange , never see some like this

bsyamato

... only thing.. this is the aircraft section

JWalker

Looks to me like the model with the castors  is designed to perhaps roll around while hovering so that if the trainee gets to crossed, the large rubber bump stops on the blue frame hit the ground and act like brakes? So my guess then would be that the goal of the operator be to keep the bump stops from hitting the ground while trying to maintaining a hover? Or it could be that it's  museum and the curators need to move things around quite often so they put those castors on for just that purpose?

Looks to me like the model with the castors  is designed to perhaps roll around while hovering so that if the trainee gets to crossed, the large rubber bump stops on the blue frame hit the ground and act like brakes? So my guess then would be that the goal of the operator be to keep the bump stops from hitting the ground while trying to maintaining a hover? 

Or it could be that it's  museum and the curators need to move things around quite often so they put those castors on for just that purpose?

Oh and you make me homesick for Ellada seeing that Frappe! Although I usually drink Freddo when Im out for cafe in Glyfada...I think too much NesCafe is bad for you :)

This is one of best scratchbild i see here and good tutorial too!! also show how the cheaper way can be great

the subject is really strange , never see some like this

... only thing.. this is the aircraft section  

It was about time to sit back and take a break! I asked “honey” to prepare a nice cold Nescafe Frappé coffee for me. I had time for a close inspection on the model so far, while she was preparing this refreshment for me. For all you who do no clearly understand what is the Nescafe Frappé coffee, please let me explain that it is a foam-covered iced coffee drink made from spray-dried instant coffee. It is very popular in Greece especially during summer, but has now spread on to other countries. In French, when describing a drink, the word frappé means shaken and / or chilled; however, in popular Greek culture, the word “frappe” is predominantly taken to refer to the shaking associated with the preparation of a café frappé. For more infos, click HERE or visit a Greek island during this summer and relax on the beach enjoying a frappe coffee to feel the Greek way difference.

You might think that I throw away the plastic straw after drinking the coffee? Hell no! Just wash with water and I had the basic material to build the exhaust tube, right on scale.

The tail rotor blade was build by styrene & sprue, airbrushed and dry fitted into place to give me an idea if it looks right.

At last the battery pack was built of epoxy and some cables and flexible air intake hoses added too. Control cables and wiring made of 0.20mm fishing line. Tail boom fins are made of forded copper and styrene. The fuel tank canisters and the fuel lines will later described. Everything covered with a light grey acrylic and placed into box to wait the final painting.