I like VTOL aircraft and was inspired to build a Coleopter after seeing this image:
The prop shroud/circular wing would be pretty easy to design and print on my 3D FDM printer, but I wouldn’t be able to reproduce the clear cockpit without considerable effort. I would have to print a blank for the forward cockpit and vacuform a clear canopy over it.
Luckily, I found a damaged copy of the Mikromir 1/35 Triton. This kit had a partially crushed left hull, so I got it for almost nothing. I may eventually build the Triton as intended (Here’s a great build review of the kit.)
You can use the images in the gallery below to follow the build description.
I decided to use the Mikromir Triton as the fuselage for a smaller, 2 manned Coleopter. I 3D printed the shroud/duct/circular wings (let’s call it the duct) as well as some of the interior structures.
The conversion started by cutting off the Triton’s tail section and cutting the cabin area open to make placing the instrument panel and crew seats easier.
I measured the original cockpit floor for the Triton and 3D printed a smaller section in ABS. The rear of the cockpit is blocked off by a 3D printed rear wall.
The cockpit interior is from the 1/35 CH-47A Crew In Vietnam, which includes the helicopter cockpit. The Trumpeter figures are terrible, with odd proportions and sizes but the rest of the kit is great.
The Coleopter’s props are from an old 1/48 Lindberg 1/48 XFY-1 “Pogo” – I found them in a box of spare parts that I bought years ago. I only have one of the internal gears that made the props contra-rotate, so I glued the props together.
The circular duct and support vanes were printed to be just slightly wider than the props. The vanes also support the rear of the Triton cockpit section.
I had to print several copies of the duct; the first version was printed hollow with very thin (0.4mm) walls and while I was smoothing it with acetone vapor, it sagged in the container and split open – the plastic felt like jello. I reprinted it with thicker walls and it worked.
The final duct design has a maximum OD diameter of 95mm, with 87mm end diameters. The airfoil is a copy of the Hanneton II (May Beetle II). After I printed the working duct, I found an article on Flight that provided more details than the drawings I found online.
The CH-47 instrument panel was cut and sliced back together before fitting into the cockpit. I used 1/32 AirScale individual instrument panel decals, which look great. The big red handle in the middle of the instrument panel is to detach the front of the Coleopter from the duct and fan works. It’s a pretty cramped cockpit and there probably wouldn’t be enough room for two ejection seats, plus the weight penalty would be significant. There’s a large hatch above and behind the cockpit that would work as the ballistic parachute access door.
The seat belts are from a miscellaneous set that my friend Jeff sent me. The “cable run” on the side of the cockpit is just part of the leftover brim used to make sure that parts stays put while printing.
The Coleopter was painted in yellow and Vallejo Ferrari red- it looks like a flying Ferrari (or Corvette)!
There’s no way that the canopy – as designed for the Triton – will fit in the rails (or even on the model) properly. Maybe my manipulations of the fuselage warped it slightly, so I ended up leaving the canopy in the open position. This does make it easier to see the cockpit details.
I used the kit’s red & white decals for the ballistic chute/access hatch. I printed the 1812 decal on my ALPS printer – it’s the year/month I finished this model. Other decals came from my spares. The Convair decal on the turboprop’s intake places this vehicle some time before 1996 when the Convair name vanished.
Kit or spare parts used: The Mikromir Triton was used for the forward fuselage and canopy. The Trumpeter CH-47A interior for the seats, IP panel and controls, the ancient Lindberg 1/48 XFY-1 “Pogo” for the counter-rotating props. Everything else was 3D printed in ABS. The landing gear/wheels had covers over them, but they didn’t look good on the model, so I skipped them.
This build was challenging but fun. I’m glad that I was able to use the damaged kit and my 3D printer to build a believable vehicle.
Updated September 6, 2020