Picture of improved motorized gigapan gear [UPDATED!]
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).

Step 1: Laser cutter absolutely needed!

Picture of laser cutter absolutely needed!
There are 90 teeth on this cog, so that means 50% more that the original 60 teeth one. The teeth actually are only 1mm thick, so you need a material like perspex which is very strong, and unless the gear falls down, there shouldn't be damages. The plastic of my old gears was much easy to cut by hand but was also more weak.
I attach the dxf file with all three cogs so that you can see or utilize it to make something similar.