Der Pummel - RC cartoon style warbird

What is this?

From the beginning, I've been a fan of the legendary fat fighters squadron. These chubby little bumblebees have one thing in common: They all look like they would never make it off the ground. Yet they do, and that - for me - is what makes their fascination.
Of course, “fat” in this respect does not mean “heavy” - quite the contrary: these models are extremely light built, consisting mainly of Depron foam plates and a few carbon rods and mostly using KF airfoils.

3D-printed airplane models, on the other hand, usually tend to being really heavy compared to not only these light-built but quite any conventionally-built models. So, would it be possible to construct a 3D-printed plane model that would be really chubby but also light enough to fly without any problems (which, in particular, means: at a moderate speed and with a good controllability)?
I had been experimenting with self-supporting doublewall constructions in vase mode for a while when this question came to my mind, and I found that this design principle offers just the properties needed to make a model fuselage with the volume to weight to structural strength ratio I wanted.
So I started drawing, printing, and assembling, and when I was finished, Der Pummel was born. I didn't bother to follow any historical example but instead turned my attention on including typical drawbacks of those, like the short nose and the thrust-robbing air inlet snout.

Here's the video of its Maiden flight, still unpainted and tail-heavy:

Note that the landing gear died at first landing attempt - It's not that it was under-dimensioned; I just had used stainless steel wire instead of spring steel… so that's the reward for carelessness/stupidity…
Other than that, I have no complaints about the model's flying behavior. Although the “fat” fuselage has its part in the flight characteristics, it steals far less power than I would have assumed. After building a new landing gear and offsetting the CG from 15% to 20% MAC, it is nicely balanced, quite slow and good-natured (yet not as slow as those Depron pendants which are still clearly lighter), and with the right motorisation it is capable of most classical (of course, not 3D) aerobatics, though it needs some space (surely no parkflyer model) . With a better pilot than me it could even do torque rolls. Just don't chivvy it too hard - due to the lightweight construction it is a little torsion-sensitive.

Wanna build it?

Nice. Definitely, you got taste. ;)
That said, I have to admit that Der Pummel requires a little more experience in model building than most of my designs (like the Sine qua non, for example). 
Firstly, you're not gonna get an assembly manual as distinct as you might expect from me. Der Pummel still is an experiment, and as such the design includes some “constructive backdoors” allowing for a differing wing, landing gear, and tail unit. Of course, you can build it just the same as I did, but if you want to use a different solution for some detail, you will find some DXF and PDF drawings of contact surfaces as well as STEP files for a all parts of the landing gear and attachment pod in the file set. The manual does not cover the assembly step by step but only explicates what is not obvious about building the model. However, if any questions pop up while building the model, you're welcome to visit Der Pummel's discussion thread on RC-Network (german language forum, but english contributions are welcome) where you can get individual help.
Secondly, Der Pummel is mostly, but not completely, 3D printed. You will have to cut (or mill), glue, and sand Depron plates for the tail units and bend some 2.5 mm spring steel wire for the landing gear (unless you want to abstain from any landing gear which is an option as well), so a little bit of model building experience will be really useful. Maybe you want to save some more weight by building a conventional rib frame wing? 

Printing notes

Der Pummel can be printed on a Prusa I3 Mk3 (250 x 210 x 210 mm) or bigger printer. If your printer has a build space higher than 400 mm, you can use the “big printer” files which dramatically reduce the number of files to print. In fact I originally designed the model to be printed on my big 340 x 500 mm delta printer, then chopped the parts to smaller pieces to allow for smaller printers to be used.

Later I found out that fuselage assembly is much easier (regarding motor and ESC integration) if the “small printer” parts for the fuselage front are used. So, maybe mixing the parts is a good idea - of course both variants are fully compatible to each other.

Filament needed is mostly LW-PLA and then something more sturdy for mechanically/thermally stressed parts - I've written a material suggestion into each of the STLs' filenames and more detailed information in the manual, but that's just suggestions. 

Printing settings,  of course, are covered in the manual. At least that part should not be left to guesswork. ;)