Profil čtvrtkruh 1,0 mm

A quarter round of one millimeter radius

The cross section is a quarter of a circle: two sides meet at a right angle and the third is convex. A strip like that drops into a corner, fills it and turns it outwardly into a smooth transition. Real machines have welds, fillets and stiffeners in their corners, whereas the mold of a kit leaves a sharp edge there, and this profile levels exactly that difference out.

When a small part goes missing

The second and perhaps even more common use is improvisation. If the frame around a hatch breaks or disappears into the carpet, a new one is made from the strip sooner than a replacement could arrive. The material is scored with a knife and snapped off, it sands as readily as the plastic of a kit, and cement for polystyrene dissolves and welds the joint, so once sanded the seam is invisible.

What that makes on a real machine

One millimeter corresponds in 1:35 to a radius about three and a half centimeters wide, and in 1:72 to something over seven. The same series offers radii of 0.75, 1.5, 2 and 2.5 mm, so for every build a fillet can be chosen that comes out faithfully in the given reduction. A strip 35 cm long is enough even with a margin for test pieces on which a modeler can try how deep it is safe to sand.

The small things it will make

The offcuts make the things there are never enough of in the box: wedges under a load so that a barrel on a truck bed will not roll, supports under a tarpaulin, a surround around a hatch or triangular braces inside a body. Anyone who keeps a compartment of offcuts reaches into it on every build, and every time a different length goes out of it.