gauge for tire profile

The tire tread depth gauge is made with an enlarged dial 6.5:1 for easier reading of the depth, because with standard gauges where the ratio is 1:1, the divisions are very small and it is difficult to see where the lines match. The accuracy is somewhere around +-0.15mm from some of my personal testing in practice.
The meter consists of three parts: the dial (also the base of the meter), the pointer and the piston (toothed rack).
I made it from PET-G material at a density of 80%, although I think it can be less dense and from PLA, although we all know that PLA melts at low temperatures, so it is not a very reliable material. The height of the layer is 0.2 mm and in order to get color differences you have to change the filament on the 11th layer and on the 14th layer you can also change the color of the filament with which you started printing. You can set all this in the Cura software in the menu Extensions>Post Processing>Modify G-Code>Filament Change.
Attached is a video on how to measure the depth of the profile with this gauge and I also measured the accuracy of the gauge with a caliper.
The red mark on the hand piston and pinion was placed so that I would know how to serge the parts correctly, and there is a small stop on the left side of the division to prevent the hand from going past the zero division. Of course, when mounting, you just bend the pointer up so that it jumps to the right.
If necessary, sand the parts a little to make the meter work better. Attention should be paid to the possibility of an elephant's foot appearing when printing hands and pistons. That's why we print the piston in the opposite position of the hand so that any thickenings are on the opposite sides.

Material PET-G
Layer height 0.2mm (first layer too)
no support required
Filament replacement on the 11th layer and 14th layer
Printing time about 2 hours