Balsa cutting tools

This time we are already starting to talk about how to work with balsa when building your own model. We assume that we already have balsa in the boards, from which we will cut slats, ribs, etc.

a) Balsa cutter - is the most used tool, even if it is completely unknown to many of the beginning modelers. It cannot yet be bought in the Czechoslovak Republic (like many other instruments) and so the only option is to make one. It's pretty easy, and the benefits this tool provides will amply compensate for the time spent building it.

balsa cutter

The balsa cutter is shown in Figure 1. A wooden or metal base plate is made of two unequal parts, connected by two screws (for a wooden base plate, wood screws of a larger diameter). However, the joint of the two parts must be straight, smooth and tight; he will be clutching his own tool - a razor blade. The blade protrudes only slightly more than the thickness of the cut board. Only the thickest (0.10 or 0.13 mm) quality blades are suitable so that they do not bend in the cut blade. When cutting a thicker board (5 mm), it is best to stagger several blades so that each blade only cuts about 1 mm (Fig. 2). With the balsa cutter arranged in this way, we can cut even hard balsa nicely straight.

If the pieces of the blade do not hold sufficiently just by clamping them between the two parts of the base plate, we can help with glue. Break the blade carefully with pliers. Watch out for your eyes! Let's take our glasses, or even better, put our hands under the table.

When cutting, we guide the board with a support plate, preferably fixed with two screws with wing nuts. The oval grooves allow you to set different widths of the cut slats. However, we must ensure that the attachment plate is always exactly parallel to the blades. Correct and incorrect settings are shown in Fig. 3. Furthermore, it is necessary that the base plate and the attachment plate are perpendicular to each other.

Moldings for indor models with a cross section of 0.6 X 0.9 mm can also be processed with the described balsa cutter.

b) A razor blade is the most common, rather dangerous, but most used tool for processing balsa, although it is suitable for cutting boards up to a thickness of only about 2 mm. However, the sharp blade will cause injury very easily and therefore it is recommended to equip it with a protective holder; however, its disadvantage is the reduction of feeling in the fingers. When cutting with a razor blade, you need to pay extra attention to the perpendicularity of the cut, because, similar to balsa cutting, it can "skate" in the material or it can be misguided - see Fig. 4. Correct use of the blade requires practice and always a considerable amount of caution.

c) X - Acto is the trade name of a universal tool for cutting balsa, which has become a term in model making; it is used by most modelers abroad. They are actually holders with a set of exchangeable knives, adapted for individual operations. Some shapes of knives are shown in Fig. 5. Knives must be made of durable steel and very sharp, otherwise the cut is degraded by breaking the edges - see Fig. 6.

d) Medical scalpel - we can consider it a Czechoslovak substitute for modeller's interchangeable knives. It is available in several types - either as one integral knife or as a handle with exchangeable knives (in this case, the shapes of the knives are not designed for modeling use, but that does not matter too much). Scalpels can be cheaply bought in the party resale of medical supplies (in Prague, for example, the corner of Opletalova and Třídy politichnich věňů). A fine eye scalpel is very beneficial.

e) A jigsaw, hacksaw and similar tools for wood can of course also be used, especially for rough cutting of larger blocks and thicker boards. You just have to pay attention to the direction of flight of sawn balsa more than with domestic woods. If we cut balsa after years, the saw engages very quickly, but it also tends to go off course.

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