When powerplant paintjob looked OK to me, it was about time to attempt mounting both 7-cylinder radial engines as required - the first one onto helicopter’s tubular frame and the second one placed on the wheeled stand. As described into through pages #8 to #14 of the ultra-detailed “1/18 Fl-282 V21 kit building instructions” manual (which can be found HERE as a downloadable PDF format file), the radial engine carefully inserted underneath the main tubular frame and placed in such way to align the engine’s four slots right onto the frame’s support beams. Since the nearby battery brackets were too fragile (only 0.4 mm thick), I had to avoid violent moves while installing engine to prevent plastic fracture. As soon as the four slots were simultaneously aligned onto the support beam heads, the engine slided backwards and secured in place by adding a drop of cyanoacrylate super glue.





The drive shaft inserted into the transmission unit’s upper opening as shown on the following pictures. The drive shaft designed as a mirrored part and therefore it can be installed either on one side or the other - no matter which side is the top and which is bottom. The transmission unit should be placed on the front of the engine block from which the drive shaft ran to upper gearbox. To do so, the block carefully inserted underneath the main tubular frame, placed in such way to align transmission’s rear opening against the 7-cylinder radial engine’s front end and secured in place by adding a drop of cyanoacrylate superglue.







Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:29

The engine’s cooling fan, proved to be the most controversial part of the kit. What really happened? Well, first things first: The Kolibri helicopter was equipped with an air-cooled 7-cylinders radial engine located inside the fuselage center-section and enclosed by outer skin. The powerplant should be efficiently cooled somehow to ensure proper & continuous operation. To do so, air was drawn in through openings beneath the fuselage by a wooden cooling fan with direct drive from powerplant provided strong air flow towards engine’s cylinders.



Despite the fact that “Luftwaffe Profile Series #6 Flettner Fl 282” ISBN 0-88740-921-0 book (released on 1996 by Schiffer Publishing, written by Theodor Muhr and originally publilshed on 1991 by Flugzeug Publikations GmbH under the title “Flugzeug Profile Flettner Fl 282 Kolibri Varianten”) says that “…continuous cooling provided by an eight-blade wooden cooling fan with direct drive from the engine…” (page #8), I could not find any front head view photograph of the so-called 8-bladed cooling fan.





On the other hand, Ryszard Witkowski author of the “Rotorcraft of 3rd Reich #5109” ISBN 978-83-89450-43-2 book (released on 2006 by MMP - Mushroom Model Publications), says that “…the engine was cooled by a wooden twelve-blade fan…” (page #24), which further complicates the question on the cooling fan issue. So, what type of cooling fan was actually fitted in front of the air-cooled 7-cylinders radial engine? Was it a 8-bladed wooden propeller or a 12-bladed? Or maybe none of the above?





To make things worst, the available diagrams are side-viewed and it’s not easy to say if the cooling fan is 2-bladed, 10-bladed or 50-bladed. IMHO, when it comes to “cooling” issue, I think that a multi-bladed fan would be more appropriate. Although a 6-bladed cooling fan had already been used on Flettner Fl-265 helicopter, the Deutsches Museum officials deny the 8-bladed or 12-bladed fan claim and they strongly support the 2-bladed propeller 90 cm Ø version - after all, they supposed to know better about Flettner 282, don’t they?



Furthermore, I spotted more errors and incorrect assumptions into the pages of the aforementioned books, which further strengthens my doubts about the accuracy of the given information. For example, it is written that Flettner 282 had not functional elevators and they were just “dummy” horizontal stabilizers bolted to fuselage frame, which is a huge mistake because blueprints, actual pictures & videos show the exact opposite. Also, it is written that all Kolibris from V20 to V24 versions were completed as two-seaters, which is also a false claim, according to Luftwaffe’s WWII and Anton Flettner Flugzeugbau GmbH files. Anyway, since I had not a clear evidence of an 8-bladed or a 12-bladed wooden propeller use on Kolibri helicopter and having in mind that both above mentioned books had already few mistakes written into pages, the multi-bladed wooden propeller story seems a little “questionable” and the 2-bladed cooling fan version is considered as the most “plausible”, just like appeared on the Focke Wulf FW-61 helicopter which already had a single 2-bladed propeller for engine air cooling. I hope my estimations / guesswork are correct and I will not have to publicly perform seppuku because of shame.





Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:30

If the assembly sequence would follow the instructions by-the-book, the two battery packs should be placed on appropriate brackets located on either side of the transmission unit as shown in the picture from the kit manual. Since the original building idea requires to setup the 1/18 scale Kolibri model in such way to look like under maintenance (or refueling) procedure with all the hatches & sliding panels opened or removed, I decided to deviate just a little from the schedule and do something different: To unplug the batteries and place them somewhere else - possibly on some wooden box or the previously mentioned wooden ladder, one of these unrelated to the helicopter structure additional parts which were designed & 3D printed to be used as part of a diorama scene.



Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:32

Those who have followed this thread from the start, will remember that the front fuselage cover had already been covered with an overall dark undercoat and later gradually airbrushed with RLM 71 Dunkelgrün FS 34079 to achieve proper gradations of light. The front fuselage cover patiently awaited the tubular frame painting completion, in order to come the turn to be properly installed. The part carefully dragged in place along the frame tubes, until reached down on the pilot’s seat & secured in place with a drop of cyanoacrylate super glue.









Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:33

CHAPTER IX - Rear fuselage section assembly

The rear fuselage section on real Flettner 282 helicopter was made of doped fabric covering over the steel and wooden frame. Those who have followed this thread from the start, will remember that the rear fuselage section had already been covered with an overall black / dark brown undercoat and then gradually lighten the surfaces to replicate the way that sunlight hits on large objects, following the Francois Verlinden’s old-fashioned way (which was re-introduced and become popular around the scale modelling community, by its new “modulation” name). The dark undercoat, gradually airbrushed with RLM 71 Dunkelgrün FS 34079 to achieve proper gradations of light, trying to balance between realism factor and artistic expression. IMHO modulation effect does not accurately replicate the reality, but it looks so artistically attractive and becomes easily accepted by our visual subconscious. Custom made water slide decals applied and later everything washed by brushing “Winter Streaking Grime” AK014 filter available by AK Interactive, until the desired colour density is achieved.

As described into pages #25 to #27 of the ultra-detailed “1/18 Fl-282 V21 kit building instructions” manual (which can be found HERE as a downloadable PDF format file), the rear fuselage cover part carefully dragged along the miniature's wooden frame, until reached down on the transmission pivots & secured in place with a drop of cyanoacrylate super glue.









Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:34

Wishing to remember this day and honor her sweet & loving memory, last week Anyuta 3D decided to make an offer for few fellow modelers & skilled craftsmen by sending a limited number of coupons. During last week, few hand-picked forum members, specialy selected talented & promising modelers, received (or about to receive) their own 3D printed 1/18 scale Flettner Fl-282 Kolibri cutaway model kits. By the time these lines are written, the parcels are on their way to modelers postal addresses.





Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:35

CHAPTER X - Parallel build challenge? Accepted

When I started this project almost two years ago, I had in mind to also present the “cutaway” model kit version step-by-step WIP, as soon as the “full fuselage” model kit building would have been completed. Actually, both versions already built multiple times as commision work for collectors (for example click HERE to see both versions frames placed side-by-side, while painting process) and I only had to write the text and later attach the pictures shot during assembling & painting process.

- 1/18 scale Flettner Fl-282 V21 Kolibri model kit - CUTAWAY version
- 1/18 scale Flettner Fl-282 V21 Kolibri model kit - FULL FSG version

Considering that over 130+ model kits of both versions sold since Anyuta 3D produced the very first 3D printed V6 version kit under 1/18 scale on early 2014 and due to the fact that the V21 cutaway version became quite popular the last few days, I am now thinking to change a little the basic plan and let the cutaway version step-by-step building edit into the full fuselage version WIP and present them both as a parallel project into a single forum thread.





As you all understand, the “cutaway” version is actually based on the previously released “full fuselage” model kit, but more than 50% of parts should be CAD designed from the start in order to achieve best results. Although both versions are accurate miniatures of the Kolibri V21 helicopter under 1/18 scale, each one follows different assembling methodology. During the CAD phase, the individual kit parts designed in such way to be as easy as possible for the average modeler to build the model. To do so, the total number of tiny parts reduced (as possible) and different components combined into one part only. IMHO, building something from scratch is not so difficult - after all, we all tried some scratch once in a while. On the other hand, designing a helicopter model from scratch, exploding it into 60+ parts and make each one of them possible to get re-assembled & combined all together in order to create a miniature, is not a piece-of-cake. Speaking of a “cutaway”, the design difficulty factor gets multiplied.



If you download the 102-page "full fuselage" and the 67-page "cutaway" PDF formated building instructions manuals, you'll notice the building process differencies on the first pages. Both versions have exact same dimensions when models fully built, but each assembling process differs a little. For example, as shown into following picture:

- The "full fuselage" version kit is equiped with four full-length rotor blades (measuring approx 28 cm long each), but the "cutaway" version has the short / chopped rotor blade parts (marked into red ellipse), to simulate the Kolibri found by British Army and now preserved by Midland Air Museum, in cutaway condition.

- The "full fuselage" version's main tubular frame is a little shorter (marked into red circle in following picture) than the normal-length “cutaway’ version's tubular frame. This is because the "full fuselage" version's rear fuselage cover part (which simulates the doped fabric covering over the steel & wooden frame and moreover has the vertical stabilizer attached on) should be dragged along the miniature's wooden frame, until reached down on the transmission pivots. So, as you understand, few milimeters of empty space are needed to ensure the appropriate contact.

- The "full fuselage" version's main tubular frame is equiped with a "sleeve" (marked into purple ellipse in following picture) over the front tubular frame. Actually this is a bracket made of wood to support avionics & radio either side of the pilot at cockpit area. This "sleeve" part as well as some others like eg batteries, avionics & radio, 25 litres cylindrical fuel tanks mounted externally on both sides of the pilot, seat cushions etc are also missing from the "cutaway" version.

- The undercarriage support (marked into blue ellipse in following picture) is different on each version. Although both versions will show the same on this undercarriage support area when models are buit, the “full fuselage” version's main tubular frame is missing this part, since it is already attached on the rear fuselage cover part.





- The vertical stabilizer of the “cutaway” version kit is offered as a separate part, which should be glued on the wooden frame. On the other hand, on “full fuselage” version kit, the vertical stabilizer is already attached on rear fuselage cover and offered as combined items.









Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:37

Approx 50% of the components are copied & pasted from the already existing full fuselage version and (lucky me) I did not had to design everything from the start. For example, the complex of intermeshing rotor gearbox, the 7-cylinders radial engine, the 24° angled rotor heads etc. On the other hand, all the “wooden frame” parts such as the vertical stabilizer, the rudder fin, the horizontial elevator fins and rear fuselage frame details, were CAD designed from the start. Ofcourse, the cutaway version was also built with all included truss-type welded tubes and drive shaft rods with universal joints attached on frame. IMHO, that was mostly preferred because all basic parts should be accurately pre-installed in place without any glue, putty, sanding etc.













Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:38

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. Once again, I was happy to hold my own custom 3D printed model kit, CAD designed with my laptop and later converted to an actual physical object, under my preferable 1/18 scale.

















Düzenleyen Nick_Karatzides - 27/07/2018 Saat 12:39