A strong magnet would work - but in fact I have found that:
- cutting 1/16" and 1/8" balsa sheet
- using a 0.5mm cutting tool and a 12v boat motor
the sideways cutting forces are sufficiently small for a simple raised lip around the cutting table to hold the sheet in place.
One difficulty with passing round files of 'cutting instructions' to people so that they can create their own kits is that the cutting machines
are all different. They will all accept 'G-Code' of some kind, but that code effectively says things like 'Go to position 25"x2" and cut a circle radius 2 inches'. Now, if you have a machine
that only has a 10" cutting bed, you can't do that. You have to reposition the part so that it fits onto your cutter
. So I've passed a DXF file to Nick - this is a CNC file with the shapes drawn on it. He will have to take each shape and position it on his machine
where he want to cut.
I have designed my machine
to be able to take a standard sheet of 4"x36" balsa, because I expect to do most of my cutting that way. If other people have cutting beds which can do this, i can pass them cutting files directly.
Another difficulty with cutting everything out of a single sheet is that one part may fall out of the sheet while cutting is going on in another part of the sheet. The best way I have found to avoid this is to not cut completely through the balsa sheet - leave a small gap of about 5 thou. Then you can easily push the shapes out later...