Balsa is the modelling wood: ultra light, very soft, it cuts at tiny powers and high speed. It is also one of the most flammable materials in the workshop.
Settings: what really matters
Halve or third the power you would use on plywood. The right setting barely goes through: beyond that, heat spreads into the fibres and the edge turns black and powdery.
Balsa density varies enormously between sheets — sometimes twofold. A test per batch is genuinely essential here.
Modelling parts are often tiny and move at the slightest draught. Reduce air assist and work on a fine bed, or your parts will end up cut twice.
Risks and finishing
Balsa catches fire very easily and an ember can keep eating the fibre with no visible flame. Never leave the machine and check every sheet before storing.
The edge stays fragile: a very light 320-grit sanding on a flat block is enough, without pressure. A coat of nitrocellulose dope strengthens the edges before covering.
Every figure on LaserSettings comes with the machine, the laser source, the material and the thickness it was tested on. A setting published for a 10 W diode says nothing about a 40 W CO2, and a setting for 3 mm says nothing about 6 mm: check those four things before you copy any number.
Settings are confirmed or disputed by the members who reproduce them, so reliability comes from cross-checking rather than popularity. Photos of the result — cut edges, engraving shades, scorching — tell you more than a single number found on a forum.
Whatever the material, treat a published setting as a starting point: run a small power/speed test grid on an offcut, clean the lens, redo the focus, work with fume extraction and air assist, wear glasses rated for your wavelength and never leave the machine unattended.