Reworking aircraft models by other authors into 1/87 scale

[gregh]

Leif, thanks again - you are amazing !!!!!

[Leif Ohlsson]

This is actually one of the very first 1/87 rescalings & repaintings I did in this series, but I've held off, since it is the only exclusively military model in this little collection. It is made from a 1/100 scale original by "Kampfflieger", and published in this version with the kind permission of Roman Vasilyev, the original author. The original model can be had by writing to him from his own site, or (more easily in fact) from the Mikromodele site (free downloads / Curtiss Helldiver).



As usual the kit contains drawings at 1/87 scale, plus in this case a rather fabulous period color slide photo (color corrected in the kit) of a couple of Helldivers preparing to take off from the deck of the hangar cruiser Enterprise at maneuvres off Hawaii in 1940.



As for the rest, the kit itself is rather pretty in clear colors, and not too many details. The enlargement (for a change) to 1/87 should make the model even easier to build:



Get the 1/87 kit from the downloads section of the site.

- Leif

This is the last repainted & reworked 1/87 model designed by others I have in stock, at least for the time being.

[Leif Ohlsson]

I have finally learned to design basic stuff in Sketchup. At least more or less, and enough to make a passable model of an aircraft. The subject chosen is the old Cessna 140, a classic light two-seater aircraft of very pleasing lines, originating from 1946. Says a chronicler at AOPA (Aircraft owners and pilots association):

Pilots who have an eye for form and function will probably agree that the Cessna 120 and its sibling, the 140, are airplanes that have eye appeal. The rounded rudder, conventional landing gear, and overall proportions create the classic lightplane look.

(Above) The Sketchup model bears witness to this (in my own view at least… ).

In drawing this model, I've adhered to the following parameters for a 1/87 scale model:

• A full skeleton (formers & spine) of simple doubled paper
• Transparent cockpit, windows, windshield & roof windows, all bent from a single piece
• Interior walls & details
• Simple pilot/pupil + passenger/instructor figures (with an option to use HO plastic figures instead).
• A properly constructed & profiled propeller, rotating & insertable as a unit at the end of the build

Here's what the model looks like if you peel off the outer layers, one after another:



(Above) The outer skin has come off. The remaining skin parts you see around the cockpit area are the inner skin parts. Their insides will be visible through the transparent windows (front, sides and roof).

At this scale, paper thickness really does come into play as a fairly large percentage of for example a former's total width. In order to really take full account of this fact, and get the formers right, I drew all surfaces, exterior & interior, as double-faced shells, with outer and inner surfaces. The considerable (and non-scale) thickness of each skin part you see, thus is the thickness of the paper. I've calculated with a paper thickness of 0.2mm.

The transparency part was drawn as double-surfaced, too (at half the thickness of the cover paper parts, or 0.1mm). It is pressed in between the inner and outer skin parts, and designed to be able to fold from a single cut-out part. The idea is that it will keep well to the designed shape as it is sandwiched and glued between inner and outer skins along the entire sides, as well as the roof inner & outer skin parts at its top.



(Above) The pilot/student & passenger/instructor (let your fantasy decide) are made of simple layered profiles, double thickness, thus having patterns on both sides of each doubled layer (although you will certainly have to touch them up with paint). There are nine such doubled layers in each figure. If they look a bit "corny", you should remember that they stand (if that were possible for them) only 20 mm (5/6") high.

The holes in the instrument panel may be too small to cut (drill) out meaningfully. We'll see.



(Above) In the engine compartment (a few front formers, and one of the propeller parts have been hidden in the image) you can see the rolled paper tube which is the fixed part. The idea here is that everything but the thick rolled paper cylinder casing rotates (prop, shaft, end stopper). This way, it can all be inserted as a unit, into the finished model, at the end of the build.

At the front end, the nicely rounded "spinner" is easy to model, since it is actually the head of an ordinary pin - which in turn may give you a hint about the small sizes involved here.

The propeller is designed according to the principles of the "simplified laminated propeller" (which you can download here in 1/16 & 1/33 scales), although the scale here is a mere 1/87. It was quite fascinating to come up with a method for drawing and unfolding this properly in Sketchup.

Very few shortcuts were taken when drawing this model, although Sketchup encourages shortcuts. Each layer of each skin section thus was "hand-stitched" point-to-point, and not just "pulled" from a former. Same for each little section of the propeller. I tried the shortcuts first, but ended up remaking most sections. If the objective is to create a model which will actually unfold, not just look nice enough in Sketchup, I found this necessary.



(Above) The fascinating part about working in Sketchup is that you can actually get into the cabin and look out from within. In the image we're just on our way in. If you want to take the final step yourself, please feel free to download the Sketchup Cessna 140 from the downloads section. I look forward to your comments and suggestions for making things simpler or better.

I'm publishing this now, just as a proper temporary holding point to the 1/87 thread. I have yet to unfold the model (Flattery is a great tool, but unfolding is a lot of work). Then the unfolded parts have to be made into a proper vector kit. And the kit colored and laid out nicely. And test-built. At any of these steps I may well find it all too much. Which is why I wanted to share the Sketchup model now. You can do whatever you like with it, including unfold it and make a proper paper model kit to share here. If nothing else, downloading it might be a good way of getting used to moving around in Sketchup, hiding and unhiding parts.

When you look at, or work with the Cessna in Sketchup, be sure to bring up the "Layers" window. From there you can hide or show all the various sections of the model. The layers are, from inside and outwards:

• Fuse spine
• Formers
• Pilots
• Details
• Cover parts interior
• Transparencies (one piece)
• Cover parts exterior
• Landing gears
• Wing & stab framework
• Wing cover parts
• Stab & fin cover parts
• Prop assembly

I apologize for the quaint numbering of the layers (as you will notice if you open the layers window in Sketchup). They are a residual from the first stage of designing, and changing them would mean an inordinate amount of work, since you have to dig down to the deepest level of each layer to change the destination of each of every little detail at its base level. That's an idiosyncracy of Sketchup, very irritating until you learn to live with it.

You would do well to keep "layer 0" invisible. It is the default layer of Sketchup, I can't change the name of it, and it only contains some residual parts useful to have around (namely the basic profiles for the figures), which look funny if you make them visible.

If you wish to carry on working on the model, please note that the Sketchup version is exactly ten times larger than the 1/87 scale model it was designed to end up as. This was done in order to get sufficient resolution of the excellent Paul Matt drawings used as a template for designing the model. (Sketchup is equally detailed whatever scale or size you work in, but the redrawn profiles, imported as .pdf files, were too coarse to use as a base for designing the model, if you didn't enlarge them before importing into Sketchup.)

Designing entails a colossal amount of work. Although I may have realized that in theory, I have so far been able to come in at the last part of the design process, fiddling with what other people have accomplished with a lot of effort. Now I know for sure from first-hand experience the amount work involved. This model took me more than a full month of pretty hard work to get to this stage.

Enjoy the model as it is now. Hopefully, it will unfold into a proper paper model eventually - perhaps at your own hand!

- Leif

[RyanShort1]

My copy of Waybe has stopped working do to an issue on the company end and it's thrown a kink in a few of my projects, but if I can get it running, I'd be happy to work on the unfolding. Nice job!

Ryan

[Leif Ohlsson]

Thank you, Ryan, for offering to help. As it turns out, I did manage to learn enough of Flattery to unfold the model. Hope you will get your troubles with Waybe sorted.




Unfolded Cessna 140 model 1/87 scale

This is the Cessna model flying around in a sky filled with parts hanging on the walls ("There were 99 paper parts hanging on the wall…").

Unfolding was made very manually with the help of Flattery, which is an excellent tool (but labor intensive, like all good design work). The features used were the "unfold" and the ".svg export" tools. The "index" & "reunite" features were not needed, and I don't foresee any immediate use for them, at least not based on this exercise.

The resulting .svg files have been imported to the Illustrator file of the Cessna 140 I will use for making the kit eventually. Some considerable amount of cleaning up remains to be done, and I will probably end up redrawing all parts to get rid of the exessive amount of anchor points resulting from Sketchup's way of working.

While doing this I am also reflecting upon the buildability of such a complicated and small model as this turned out to be. I'm not so sure about my own ability, but will do my best to present something that a more accomplished builder might tackle. I've seen examples of just as complicated models in even smaller scales (the flying boat PZL.12 by Krzychu74, Mikromodele, comes to mind - see this previous post).

If you want to play around with the unfolded parts, get it from the downloads. You will need Flattery to enable export the two big chunks of parts hanging on the walls as .svg files. It might be a good exercise, if you are so inclined, to see what it entails making a real working paper model part from the unfolded stuff coming out Sketchup/Flattery.

Note that the unfolded parts have been grouped together into two huge groups (one wall each, and facing each other 90 degrees). The result if you let Flattery export them is two huge (in size, not kilobytes) .svg files, which can be opened in any vector programme (like Illustrator).

Please regard it as an exercise. At this stage I can't guarantee that I've got all details perfectly right.

A few tips here:

• The unfolded chunks of parts coming out of Flattery exported .svg files are inverted - you need to turn them around 180 degrees.
• You need to rescale all parts to a mere 10 percent, if you want the scale of 1/87 - which the parts were designed for.
• Once you have a look at the parts in your vector programme (like Illustrator), you will notice that there are three large packages for each chunk, namely "internal lines", "external lines" (outlines), and "faces" (surfaces). Delete the "faces", and clean up a few of the internal lines that shouldn't really be there (remnants of hidden Sketchup construction which I couldn't get rid of in Sketchup). A few lines may need adding (like the leading edge of one wing). That's the way it goes with these things.
• Reduce the two remaining groups (internal lines and outlines) into one common pool. Then isolate and group each part. But you already got that, right?

After that, and some rearrangement of parts into proper kit pages (two A4 or Letter size sheet should be sufficient), you could print and build a white model.

Or you could go on and recolor. If so, you would very much want to redraw the parts, using the exported parts as mere templates. The reason is that the lines do not form proper fields suitable for coloring.

That will be my own next step.

- Leif

[birder]

Wow Leif you are very busy with these fine tiny aircraft, I am very much enjoying this thread, no suggestions to offer as your work is great and impetus to learn CAD in some form to also contribute.....my models becoming increasingly outdated being hand drawn....As others have said I was surprised that your scale has "slightly" changed...

[Leif Ohlsson]

Well, Glen. I think had a sort of wish to complete things once started, never quite finished. This one started may years ago, at Kartonbau.de (no worries, it's all in English).

I couldn't really do much about it at the time. This one's better (perhaps too elaborated, but still...).

Thanks for letting me know you're watching!

- L.

[hemingway]

Hi Leif,

great stuff! You finally did it! Congrats!

With some melancholic feelings, I remenber your first adventures with sketchup ...
An absolute beginner's adventures in SketchUp - Das Konstruktionsbüro - Kartonbau.de - Alles rund um Papiermodelle, Kartonmodellbau und Bastelbogen

Bernhard

[RyanShort1]

Sweet.

Ryan

[Leif Ohlsson]

And thank you, Bernhard, for actually teaching me how to use Flattery, once upon a time...

Leif