|Kit:||converted from resin kit of the Grunau Baby by Czech Master Resin, 1/72; £10.50 at Hannant's in 2009; completed on 2009-12-30|
|Aircraft:||Sole prototype "OH-PXA" in its original, 1949 configuration with an Aubier & Dunne 17 hp engine.|
PIK-10 at the Finnish Aviation Museum; note the new engine and canopy
PIK-10 was the first powered glider constructed in Finland, and also the first aircraft registered under the newly instituted "experimental aircraft" class. Its designer Carl Stunde used an old, wrecked Grunau Baby II airframe as the starting point; a new nose, with engine, was constructed, and a landing gear was added. First flight took place in 1949, at which point the aircraft had an Aubier & Dunne 17 hp engine. Later, a more powerful 28 hp Pincard engine was installed and also the canopy was modified. In this configuration the aircraft is currently preserved at the Finnish Aviation Museum.
In short, I converted the Grunau Baby kit exactly like the original builders converted an actual Baby airframe. The CMR fuselage comes in one solid piece. Since the PIK-10 cockpit is further back than in the original Baby (because of the center of gravity), I had to cut off the fuselage and build the front part completely from scratch (see diagram). Essentially it is just a "built-up box" (as Harry Woodman calls it). A piece of plastic tube was affixed in the nose and sheet plastic wrapped around it for the right contours. After that, the rest of the nose was built up. Green Putty was used liberally. Cockpit interior consists of the seat from the kit and a new instrument panel. Cowling was built over the front fuselage separately from 5 thou plastic sheet.
Initial cut of the fuselage
Fuselage sides wrapped around a plastic tube
Liberal application of Squadron's Green Putty
Fuselage bottom sanded down
Building up the top of the nose
Inside structure visible
Beginning to build up the cowling
Jig for straightening the wing
The rest of the model, apart from details such as the engine, propeller, landing gear, etc., is pretty much the CMR kit straight out of the box. The wing, which comes in a single part, was badly warped, so I constructed a makeshift jig (see picture) and dipped the part in boiling water. After the part was cooled with cold water it had the right shape and dihedral angle. To ensure that it stayed that way I cut off the ailerons and mounted them in slightly turned positions; this, effectively, greatly increases the bending rigidity of the outer sections of the wing.
In the Baby, the elevators were distinctly separated from the fixed parts of the horizontal tail. This is incorrect in the kit and had to be corrected. Tires came from the spares box, with wheels themselves built from scratch. Tailwheel came from the spares box as well. All struts were made from plastic strips, and ontrol surface actuator rods and cables were added. Windshield was built from transparent plastic sheet. Finally. the propeller was carved from plastic strip (very much the same way wooden propellers are made from laminated wood), with the hub and shaft from plastic rod.
The model was painted entirely with Model Master acrylics. The orange color was mixed from "Guards Red" and "Insignia Yellow". The trim was masked using Tamiya masking tape (it works well with acrylic paints and does not pick up any paint). For decals, I first tried printing orange on white decal paper, but when cutting and trimming the paper some orange tends to chip off and the result if not satisfactory. For the second try, I had white decals printed by Fireball Modelworks.
PIK-10 in the early 1950s