Lay thicker plywood sheet on workbench. Using ruler and pencil, measure and mark 30cm from left side, top and bottom. Draw a line between marks. Along the line mark at 8cm, 16cm and 24cm from top. Using drill with spade bit, drill holes at marks. Place dowel on workbench. Using ruler and pencil, make marks at 10cm, 20cm and 30cm (above). Using vice and jigsaw, cut dowel at these marks to make three smaller pieces. Sand ends thoroughly and wipe off dust.