To make impressive gigapixel images with much more resolution I needed to increase the number of photos per line, i.e. the number of teeth of my DIY gigapan motorized gear
There were two ways: to enlarge the diameter of the gear (but so I'd have also to build a longer brace between tripod and motor), or to try to make much little teeth on the same diameter. Second choice should have been impossible to make by hand, but with a laser cutter perspex plate it has become reality (thanks to Waldy
which helped me).