1/18 scale Flettner Fl-282V21 Kolibri scratchbuild

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

After digitally building the Fl-282 Kolibri 3D model using only mouse clicks, I saved it as an STL - STereoLithography format binary file and forward it on the 3D replicator to start generating the individual parts of the actual scale model. To do so, I used the best available tools & plastic material and asked from Shapeways, a special digital fabrication lab equipped with a high-precision & high-cost “ProJet HD 3000” machine for creating custom made-to-order products, to 3D print it. The 3D printing material used was a special plastic called “VisiJet SR 200”, a UV light cured acrylic polymer plastic material for 3D printing with ± 0.025 mm accuracy for every 25.40 mm. It’s actually an organic mixture, consists of 55% triethylene glycol dimethacrylate ester and 45% urethane acrylate polymer. It is printed using the “MJM” aka Multi Jet Modeling process. During this MJM process, cartridges of acrylate and/or wax material are heated and the plastic material is fired in ballistic micro droplets from a multi-chambered print head containing hundreds of Piezo jets. Molten plastic is deposited onto an aluminum build platform in layers using several nozzles, essentially like a large print that sweeps across the build layer. As the heated material jets onto the build plate, it solidifies instantly. After each layer is deposited, it is cured & polymerized by a wide area UV lamp. The next layer then applied, and through this repeated process layers of thermoplastic build up into a model. This method can print durable plastic parts with a high level of detail and accuracy as well as burnout materials and real wax parts for casting. Layers can be as thin as 16 microns, so MJM produces fantastic surface finish with minimal “stepping”.

The 1/18 scale Fl-282 V21 Kolibri “full fuselage” model kit consists of 60 different 3D printed parts made of matte translucent plastic material - in fact, the kit parts are quite more, but smaller in size are interconnected on same sprue frame which is counted as one part. Kit was CAD designed and 3D produced in such way to simplify assembling process while maintaining necessary details required by the scale size. Following the instructions described into the 102-page ultra-detailed “1/18 Fl-282 V21 full-fuselage kit building instructions” manual (which can be found HERE as a PDF format downloadable file), the assembling process becomes easy.

When printing is finished, the model parts are removed from the tray and placed into an oven that melts away the wax support material. Next, the models are placed into an a ultrasonic oil bath to remove any remaining wax residues, and then a ultrasonic water bath to remove any oil on the model. Final inspection and dry by hand follows for every single model part. Although the ProJet HD 3000 prints in high resolution (16 microns per layer) and can easily produce high detailed parts as small as 0.1 mm, it is better to avoid printing such small parts because they could easily get lost while washed into ultrasonic bath later, for wax residues removing.

Keep in mind that due to increased 3D printed items manufacturing demand and workload in Shapeways factory, a complete model kit takes about 5 to 7 days to get produced after order. Depending customer’s location, the 3D printed parts are produced at one of two Shapeways production lines based at NYC Long Island, USA or Eindhoven, Netherlands and shipped Worldwide, (24hrs to 48hrs delivery time) right at your doorstep by USPS, UPS and DHL with most reasonable prices.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Shortly thereafter, the 3D printing proceeding outcome pleased me while watching the Mbytes, magically converting into actual physical objects. Yeah, that’s what I call “cool gadgets” on a scale modeler’s service. As soon as 3D printing process completed, the produced parts were cleaned & checked for broken parts or imperfections by Shapeways 3D printing lab specialized personnel. Later, everything carefully packed and shipped to my home address using UPS 24hrs delivery service. Next day, I got home to find a Shapeways box on my doorstep. After a long eye roll from my wife, I quickly grabbed a knife and opened it like all kids open their presents on Christmas morning. Nothing out of the ordinary, I decided to take a few photos to illustrate the experience of receiving my own custom designed & 3D printed model kits package and get in my hands the result of my very own custom-made kit, designed with laptop mouse clicks only and built from zero by converting a CAD binary file into an actual physical object, under my preferable 1/18 scale. Cool stuff, isn’t it?

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Each one of the two complete custom-made kits consists of 60 different 3D printed parts, some quite big and some others so tiny that could be easily become victims of the carpet monster. The only difference between these two Kriegsmarine’s V6 and Luftwaffe’s V21 custom-made complete kits, is that the single seat V6 version kit contains an extra cover for the observer’s rearwards facing “office” just behind the rotor shafts. On the other hand, the two-seater V21 version kit extra contains the two cylindrical 25 lt fuel tanks placed on either side of the cockpit, which are absent on V6 naval kit.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Each complete kit contains the basic frame sections, the elevator & rudder fins, the landing gear wheels, the 7-cylinders radial engine, the upper rotor transmission & gearbox, the rotor heads & rotor blades, the two cylindrical 25 litres fuel tanks (V21 kit only), the cockpit compartment with front & side instrument panel, the control stick with thrust & collective levers & the rudder pedals, both crew seat frames (2nd seat for V21 kit only), a couple of cowling & opened for maintenance hatches and plenty of additional minor details such as supporting rods, control bars, knuckle joints, pulleys, hinges, D-rings etc, etc, etc. Some cable wires & rigging will be later added manually. As said before, any extra diorama accessories visible on some pictures (eg. engine's stand, fuel drums, fire extinguisher, jerrycans, wheel chokes, wooden ladder etc) are not included into kit but is possible to get 3D printed and be purchased separately.

 

[moon puppy]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

So jealous of your 3DCad skills, I had a crash course in cad work the other week working on a network diagram and am in even more awe.

So where we at with this now?

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

So jealous of your 3DCad skills, I had a crash course in cad work the other week working on a network diagram and am in even more awe.

I am just a moderate level scale modeler with same skills as many other person here. In fact, I'm sure there are much better and more talented scale modelers in this forum, than me. If I (with no special CAD studies and no professional speciality on computers) am able to create CAD files for fun and later print them as scale models, anybody can do it! If I managed to learn how to 3D design, improve, reconstruct & print my own models, in only few months period by reading articles found in internet, anybody can also do it - possibly much better than me.

Feel free to follow my previously uploaded WIP articles here. You'll find that I always try to present a full "package", to offer a info about the real aircraft / helicopter and modeling tips & techniques as well. Have a look on following pictures for some projects already presented here in modelersalliance forum.

This Flettner Fl-282 V21 Kolibri helicopter (available in "cutaway" version too) and a Bleriot XI-2 WWI monoplane model, both designed & produced in huge 1/18 scale, are available for sale as full 3D printed kits, produced on high-precision 3D printers by using best available polymer plastic material to ensure the best printing results & highest possible quality on kit parts. Interested collectors, scale modelers & hobbyists could follow the building process and have a look on Work-In-Progress detailed pictures.

Click on Anyuta 3D printed scale models online catalog to have a look.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

It’s been a long time, more than one year as far as I can remember, since my last update into this forum - not unreasonably as you’ll find out by reading the following lines. You see, 2015 almost as a whole year, was for me and my family - or at least what is left of it - a very bad year. Life is full of surprises and reminds us daily that we are only human beings, absolutely vulnerable to almost anything. Life prooves by most cruel way that we can become nothing more than dust and faded memories, at any moment, in just a blink of an eye. The following text and attached photos are about two years old and were supposed to be published on scale model related forums & magazines in late 2014 or early 2015. Unfortunately, we may make our plans but God has the last word and decided to take my angel for a while until we’ll meet again on the other side. I'm not worried - I know she is patiently waiting for me to join her some day and I pray for this day to come soon.

Although the above lines are not directly related to a hobby forum, sharing my thoughts with fellow scale modelers, relieves pain and makes grief a little softer. However, I would greatly appreciate if public comments & responses will be exclusively focused on scale modeling matters.

 

[moon puppy]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Nick, please accept my heart felt condolences. May God be with you and your family.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

When I first got this 3D printed kit in my hands, I noticed that most of the kit parts had slight traces of oil on their surface, so each time I touched the parts, my fingertips become oily. What really happened? Obviously, after the 3D printing process was finished and the kit parts been removed from the printer tray to be washed into an ultrasonic oil bath and later an ultrasonic water bath, some oil traces escaped the clean inspection and dry by hand procedure. When I later examined all parts by touching one by one with bare hands, I accidentally transferred the oil traces to every single part. When I realized it, it was already late. Well, it was not exactly a doomsday, but the kit parts should be cleaned thoroughly, because even the slightest trace of oil on the surface of model, could potentially be a problem in the painting process. Simplicity makes things flow without effort and oil traces could easily be completely removed by sinking everything into a 2 litres plastic bowl filled with White Spirit and leave it there for few minutes to wash oil traces. Shortly after all kit parts enjoyed their bath into a White Spirit filled bowl, they were washed with liquid soap and warm water and placed on soft paper towels and allowed to dry.

After all kit parts washed in White Spirit & water to clean the oil traces, every section of the model has been repeatedly dry fit tested to ensure that all individual parts could be later combined together as an overall built model. When looked OK to me, each part sprayed over with Ammo Mig Jimenez AMIG2004 “White waterborne polymer primer” to spot mistakes and prepare for paintjob. The next day, I did a visual inspection and shot some pictures. It looks that overall white primer, really helped to visually pop-up the printed detail and proved that use of best available 3D printing material resulted smooth and glossy surfaces on kit parts. As always, the final check held by my sweetheart wife who conducted a strict quality control and 3D printing result evaluation. With persistence on detail, she examined each one of the kit parts and compared them with the CAD design on computer screen. In fact, she spotted an almost undetectable tiny crack on a frame rib inside the helicopter fuselage, which had escaped my visual inspection earlier. Once the process complete, she smiled & proudly signaled green light for further building.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

CHAPTER III - Individual kit parts assembling process​

As soon as the parts were already cleaned & dry fit tested, it was about time to start assembling everything as one model. I usually follow two simple rules while attempting to assemble kit parts and later paint a model:

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

First option seems as more appropriate - it would surely make my life easier to paint individual parts first and assemble all together later.

As already wrote into previous paragraphs, the model was 3D designed in such a way so as to avoid creating gaps between the parts to be later assembled. Notice that, no filler putty used and no sanding done throughout the whole process! Most of the kit parts, such as the tail rudder & horizontal stabilizer fins, the pilot’s & observer’s seats, the main & nose landing gear wheels, the cylindrical fuel tanks, the upper gearbox and of course the rotor blades will separately paint, weathered and later be attached on model’s overall structure using CA superglue, which does bonds in only few seconds, reaches extremely strength at room temperature and it is suitable for materials such as wood, rubber, plastic, metal, ceramics, leather, marble, polyethylene, polypropylene, teflon etc. On the other hand, there were few tiny parts such as some hinges & D-rings on main fuselage and gearbox complex that had to be assembled before painting process start.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

CHAPTER IV - Applying paint, wash & weather effects​

Before dealing with this project, I had the (false) impression that Kolibri helicopters were all same - at least identical. After all, only 24 were produced. Once again I was wrong. Study & research on available printed material, 3view diagrams, photographs and videos actually reveals that there were plenty of differences between them - obvious differences or just small details identified after careful observation. In some cases, the exact same helicopter (for example the V12 with registration CJ-SF) was appeared once to be painted with Kriegsmarine’s medium grey camo (click HERE) and later with Luftwaffe’s dark green colours (click HERE) or even once having the flat plexiglass panels around the cockpit installed and latter simply missing them. On the other hand, the two-seater Fl-282 V21 helicopter registered as CI-TU, maybe the most famous of the Kolibris, was quite unique. In following picture, dressed up with Luftwaffe’s TransportStaffel TS40 colours, as appeared at Ainring AB at Mühldorf, Bavaria, in it’s operational role as artillery spotter, back in 1944 to 1945 days.

 

[moon puppy]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Absolute genius

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

To recreate the Fl-282’s Luftwaffe camo paint, I did use the Life Color’s “Gerrman WWII Luftwaffe set #1” 6-pack set, of 22 ml bottles.

• Life Color UA501 RLM 70 Schwarzgrün / Black Grey acrylic paint,
• Life Color UA502 RLM 71 Dunkelgrün / Dark Green acrylic paint,
• Life Color UA503 RLM 65 Hellblau / Light Blue acrylic paint,
• Life Color UA504 RLM 02 Grau / Grey acrylic paint,
• Life Color UA505 RLM 79 Sandgelb II / Sand Gold II acrylic paint and
• Life Color UA506 RLM 80 Olivgrün / Olive Green acrylic paint.

To be more specific, the basic colours applied on model according WWII Luftwaffe ReichsLuftfahrtMinisterium designations are the RLM 71 Dunkelgrün FS 34079 & RLM 65 Hellblau FS 26329 paints.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Pre-shading by airbrushing dark coloured lines on model before the basic paint is a method followed by many modelers the last few years. To be honest, I never liked it, never really understood the reason to do something like that and yes, I admit that I never had some decent results whenever I tried it. IMHO adding pre-shading lines before painting is a time wasting & useless procedure with no artistic results on model. After all, what’s the reason to try this, if (one way or another) additional paint layers will be applied on model later, to enlight or darken the basic paint? Anyway, I mostly prefer to:

• Directly apply the basic paint (without pre-shading and other time wasting nonsense) and later add some colour shades by enlightening or darkening on specific areas or
• Follow the Francois Verlinden’s old-fashioned way by airbrushing a very dark colour (usually some black & dark brown mixture) all around the model until fully cover it and later gradually light-up the model’s surfaces by repeatedly applying very thin layers of basic paint.

The abovementioned Francois Verlinden’s way possibly practiced by other painters & hobbyists decades before, was first introduced as a painting technique for scale modelling by Francois Verlinden, more than 25 years before. Back in the late 1980ies days, when the internet was not known yet and modeler’s only available reference was the (usually expensive) books from local hobby shop, a Belgian artist named Francois Verlinden managed to create 3D-alike light effects on flat surfaces. He did that by repeatedly airbrushing very thin layers of basic paint on a black (or dark brown) undercoat and then gradually lighten the dark surfaces to replicate the way that sunlight hits on large objects. Since then, some new painting tricks appeared and many modelers improved some older (and forgotten) techniques and re-introduced them as their own “new” inventions. During the last few years, the Francois Verlinden’s old-fashioned way was re-introduced and become popular around the scale modelling community (especially among armour painters), by its new name: “Modulation”! IMHO this modulation fashion looks nice on models but the results are not so “strictly realistic” comparing to the real world objects. As scale modelers, we always have to balance between realism factor and artistic expression. Yes, I admit that modulation effect does not accurately replicate the reality, but it looks so artistically attractive and becomes easily accepted by our visual subconscious.

Process started, by airbrushing an overall undercoat mixture of 80% Life Color LC02 Matt Black and 20% Life Color LC37 Matt Burnt Umber acrylic, to prepare the flat surfaces for the basic paint which about to follow. Asking a blonde to “paint it black” could be confusing for a moment and result some priceless answers.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Having succeeded (in her first airbrushing attempt) to spray black paint onto my clean & tidy hobby bench, I realized that it was time to urgently have a new spray booth for her, considering that my old one broke down after almost 15+ years of use. My initial thought to buy a brand new one, quickly dismissed when I found that the cheapest China-made spraybooth was quite small for my big-sized scale models and the purchase price could start from €100 and rise up to €500 or more. Additionaly, due to limited space on my hobby bench and the fact that I usually build big (close to huge) scale models, the spraybooth should be large enough to fit models inside, portable to keep clear the working bench when not in use and should be easily (and fast too) disassembled and stored under the bench.

Well, as a good friend once said, “everything starts with a wish” and “inspiration can be found everywhere”. I found the following item named “Sortera” which supposed to be a recycling bin with lid or something, at my local IKEA store. Looking exactly like what I’ve been searching for and considering the low €15 price, I bought this 60 litres plastic box (IKEA product code is 702.558.99) and turned it into a paint chamber. Later, I also visited my local Leroy Merlin home depot (located right next to the aforementioned IKEA) store, trying to find the right parts for the project, such as bathroom ventilating fans, outflow plastic tubes and electric wiring. I found two 125 mm diameter bathroom ventilator fans rated at 32 W, 10 dB, 150 m3/h each for only €11 each.

The purchase cost for buying materials to build the DIY spraybooth was:

• 2 x ventilators rated at 32 W, 10 dB, 150 m3/h each: 2 x €11 = €22 EUR,
• 1 x paint chamber (“Sortera” recycling bin with lid from IKEA): €15 EUR,
• 2 x PVC 125 mm Ø plastic tube 90° fittings & bezel parts: €3 EUR,
• 1 x PVC 125 mm Ø plastic tube 50 cm long: €1 EUR,
• 1 x common kitchen extractor hood filter: €1 EUR,
• 1 x electric wiring 2 m long & switch: €2 EUR.

The total ammount with all the hardware was €44 (approx $48).

As soon as returned back home, I spent nearly one hour to assemble parts and make the scratchbuilt spraybooth fully functional. The first ventilator slided through the tubular wall opening (already existed for the previous broken spraybooth outflowing), secured in place and got wired to 220 V with a switch. The exterior wall opening is covered with louvers that automatically close when the ventilator fans are turned off, to prevent ingress of cold air in the room during the winter. Furthermore, when spraybooth is not in use, the inner wall opening is manually sealed with a proper cap.

Later, the second ventilator mounted on a 125 mm wide drilled hole on plastic paint chamber side and connected to 220 V with seperate wire & switch. Between the two in-line-mounted ventilators (one located at the beginning and the other at the end of suction flow), a portable S-shaped 125 mm diameter tubing of total length 75 cm is inserted. At last, a common kitchen extractor hood filter installed, to prevent paint particulates entering into the airflow circuit.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

As I later found out when first tested the spraybooth, the ventilators proved more powerful than expected, producing a suction flow of total 300 m3/h, meaning that (if my calculations are correct) the air inside the 60 litres paint chamber is renewed every 0.72 seconds. During the first airbrushing test, I noticed that the spray beam got warped (!!!) close to 90 degrees angle, towards ventilation fan and therefore I placed additional filters to reduce the airflow power.

Long story short? My scratchbuilt spraybooth:

• Cost me €44 EUR (approx $48 USD) to buy the hardware, plus one hour work to assemble parts & install electric wiring,
• It has a 60 liters (measures 55x45x39 cm) paint chamber able to accommodate big-sized scale models,
• It is almost operating silently, not exceeding 20 dB when both ventilator fans are in use,
• It is fully portable (can be assembled or disassembled in less than 10 seconds) and
• It sucks air like an inverted hurricane, even when filters are installed!

Having now a new fully functional & custom-made spraybooth, lets return back to to the painting process: All the 60 parts of the model kit, placed onto toothpicks for better handling while airbrushed and sprayed over with an overall mixture of 80% Life Color LC02 Matt Black and 20% Life Color LC37 Matt Burnt Umber acrylic as a primer, to prepare for the later paint layers. The toothpicks pinned onto cork sheet and parts allowed to dry.

Behold the spraybooth filter, after 30 minutes of continuous black paint airbrushing into paint chamber. The use of this simple kitchen extractor hood filter kept the system clean. Double (or even triple) filter layer would be a good idea to reduce the airflow power in order not to warp the airbrush spraying beam (as previously described) and could ensure that components will remain spotless clean for a long time. If there was no filter at all, dirt & paint particulates would easily enter into the airflow circuit and stick onto the ventilator fans and the plastic tube inner walls.

 

[Piet]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Beautiful...........and so are your Choppers

 

[phantom II]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Very nice instructions for a spray booth .

Let me make sure I got this right.

It require two separate fans to run in the same duct ?

Cheers, Christian B)

 

[moon puppy]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Chris looks to be only one fan installation.

 

[Nick_Karatzides]

1/18 scale Flettner Fl-282 V21 Kolibri scratchbuil

Very nice instructions for a spray booth . Let me make sure I got this right. It require two separate fans to run in the same duct ?

@ Christian,

Well, I think that the phrase "...it require two separate fans to run..." is not just right. You can place only one, or two, or maybe ten of them if you are planning to build a flight test wind tunnel. The reason I bought two ventilators is because I found them both in a low-price (€11 each) and installing one at the entrance of the airflow circuit and another one at the exit to establish a continous and strong airflow, sounded like a good idea to me.

As said before, each ventilator can extract 150 cubic meters of air per hour. Placing them together in same line, I guess that the total air extraction power can be close to 300 cubic meters of extracted air per hour. Considering that the plastic recycling bin used as paint chamber has 60 litres capacity, my calculations (if right) show me that the air (paint fumes and particulates too) inside the paint chamber is fully extracted every 0.7 seconds ! That means that you actually have no paint fumes and particulates "flying" around in room when airbrushing. As previously said, the combination of these two specific (rated at 32 W, 10 dB, 150 m3/h each) ventilators proved more powerful than expected, producing a suction flow which makes the spray beam got warped close to 90 degrees angle, towards ventilation fan. Therefore I placed additional filters to reduce the airflow power to normal limits and not something like an inverted hurricane.

The reason I used this plastic recycling bin (with glossy surface) as a paint chamber is also because all the mess after airbrushing can be easily cleaned / wiped with a piece of wet kitchen paper and remain clean for next time. The white colour also provides better lighting. As for the noise while system is operating? Only 10 dB, meaning about the same like your silent compressed air generator while airbrushing.

PS. If you also noticed, the right side of the paint chamber (as you see this on picture) is wider and the plastic wall is placed angled, giving more space for a right-handed modeler like me to move the airbrush holding hand freely.