You will need
- - foam;
- - a saw-a hacksaw, a metal string or nichrome wire;
- jig - saw;
- - machine for cutting.
First of all, pick up any foam. The fact that the most simple, cheap construction of coarse-grained polystyrene poorly suited as a material for cutting: they much crumble, when cutting will be defects ("shell"). This polystyrene has a density of 10-15 kg/m3. Regardless of price, to buy its not worth it. Better spend more money but buy quality, fine foam, which almost does not crumble during processing. The density of such material is about 25-35 kg/m3.
Cut the foam using different tools: fine-toothed saws-handsaw, taut metal strings, the heated nichrome wire. The first method is used very rarely and can be recommended only for initial, rough treatment, because even with the most careful work may be of the shell and chipped at the edges of the cut. So much better to use the string clutched in the jigsaw.
It is important that the string was well stretched. If it is stretched badly, it almost certainly will make "shells". Given that foam is a very soft material and the resistance of resa the minimum, do not be afraid that the string breaks.
It is better to purchase a machine to cut or do it yourself. The main significance of this fixture to a piece of Styrofoam was fixed, and the jigsaw was moving vertically, then the probability of marriage will be minimized.
Red-hot nichrome wire is used mainly when you need to make complex or curved cut. Ways of fastening wire, there are many. Typically, each master uses one that he was accustomed and more comfortable. Some fans put the working area of wire in half, forming a kind of stinger device to burn, very popular in Soviet times.