Sunday, November 8, 2020

Graupner Klemm 25

The original Klemm 25 was first available in 1928 as a light two-seat touring and training aircraft. My model is based on a Graupner Klemm 25 kit from a lucky EBay find, which then became a Corona Summer of 2020 project. Built as per instructions, except replacing the vacuum formed part for the cockpit with strip-planked wood. Fuse is covered with cloth/epoxy, wings and rear with 'Nelson light fab'. All coloring is Tamiya paint, both glass and rattle can. Filled the cowling from the kit with plaster, then vacuum-formed a copy to have replacement part. Pilot is 3D printed.
Wingspan130 cm
Weight830 g w/o Battery
Battery3S 2200 mAh Lipo, 185 g
MotorSpeed 400, gear
Full-throttle current draw is 10 Amp, 120 Watt. First flight in June 2020. Motor's gearbox is quite loud. Barely climbs at full throttle, but can fly nice slow circles at 1/3rd throttle. Uses about 100 mAh of battery capacity per minute flight time. Makes for enchanted early morning or late evening flights in zero wind. Very convenient that whole plane fits into car, no need to remove wings etc. Only downer are the water-slide decals. As applied from the kit, the transparent backing shows up shiny/silvery. Tried to 'melt' them into the paint by dabbing with vinegar as well as acetone. The latter helped a little, but masking and then spraying the numbers would have been way better.