Hercules C130

A few years ago the Nördlingen Modeling Club was hit by a severe case of Foam Fever. The culprit was Udo Bloch and his infectious foamies. Completely made of light beadboard foam (brand name "Styropor" here in Germany), such planes can be built on one weekend. They're low-weight (thus excellent performers) yet provide tons of fun. The planes usually are "standoff scale" - it's ok if they look good from a few meters away and in flight, no need for much detailing.

Today, many foam planes can be bought in kit form. Nevertheless, those who still know how to handle a foam cutter might enjoy our simple plan of the grandfather of all foamies - the Hercules C130!

	Layout drawing of the all-foam C130.
DOWNLOAD	C130.EXE (51K) - a self-extracting archive - contains DXF drawings of general dimensions and the foam cutting templates.

To unpack, copy C130.EXE to an empty directory and run/execute it. For viewing and printing you need a CAD or other drawing program (for example, CorelDRAW!) with DXF import capability. C130.dxf has the outline drawing, C130-s1.dxf the fuse tube cutting templates and C130-s2.dxf the wing cutting templates.

Cutting the fuse:

You need two large rings and one small disk. Cut the fuse tip over the outside of the rings only (producing a solid cylinder - make the cockpit shape with a kitchen knife and a sander) and the middle fuse tube first over the inside and then over the outside of the template rings (producing a hollow tube). The rear part of the fuse is a hollow tapered tube - use one of the rings and the disk template.

Cutting the wing:

Cut each of the three wing pieces (middle, left and right) from the bottom near the leading edge up around the leading edge and back to the trailing edge. After glueing the wing parts together, cut off the trailing edge to the chords indicated in the outline drawing (inboard template is 250mm - cut to 230mm; outboard template is 130mm - cut to 120mm). This results in a blunt trailing edge which is much less prone to damage.

Reinforcing the wing:

Cut a spanwise 3 x 3 mm groove into the upper and lower wing surface at about 30% chord and glue in 3 x 3 mm pine spars. Cut apart the horizontal and vertical stabs at about 30% chord and glue in a 10 x 2 mm pine spar.

Wing support:

Use the leftovers from cutting the fuse tube for filler blocks supporting the wing. Both the wing's lower surface and the horizontal stab should be parallel to the fuse upper contour (0 degrees incidence angle).

Drive System:

4 Graupner Speed 400 (7.2V) motors and Graupner 6 x 3 props. Make glass or cardboard tubes with an inner diameter equal to the outer diameter of the motors. Glue the motor rear ends into the tubes (make sure to leave the cooling vents open) and the tubes into the wing. A few glass reinforcements are in order. Use a good electronic speed controller (rated for at least 40 Amps), preferably with BEC. You will most likely fly with reduced power most of the time, so you might find you need cooling vents for the speed controller.

Finishing:

You can simply paint the thing with wall color or acrylic water soluable color (make a test first to see if it doesn't mess up the foam). For a better and more durable finish, cover with paper, fill, sand and spray paint. Get yourself a 3-side view of the plane and apply some detail like panel lines and markings (with a thick felt tip marker).

Other:

Keep the plane light. You won't need rudder, just three micro servos (max. 20 grams) for elevator and the ailerons. Use epoxy for all foam glueing.

Have fun!