Because this Project has many different versions and options, the amount of files can be quite overwhelming and confusing. To make things easier, use the "Printed Parts Chooser"
Go to File > Copy and copy the sheet into your own google account to be able to use the checkboxes. Select the options that apply to you and print the files that are marked green.
Print the Calibration part and use the following image to compare your print to the necessary tolerances. A digital caliper is useful.
If youre using Cura, you can use the features “Horizontal Expansion” and “Hole Horizontal Expansion” to alter print- and holesizes without changing your printers calibration.
Beware of slicing tolerances!
This is something i just recently figured out, but the stock Cura slicing tolerance (found in the Experimental Settings) is "middle", and as such, all parts are optimized for this. However, Prusaslicer uses some sort of "Exclusive" slicing, which will cause any holes to come out slightly oversized. Be sure to slice the parts with Cura set to "Middle" and wherever possible use Cura over Prusaslicer for now.
Parts should be printed using PLA.
Most Parts do not need much precision or need to be very sturdy.
Generally, for all parts you should be using at least 3 Walls (perimeters) and 3 top/bottom layers. 15-20% infill and 0.2mm layer height will be enough.
Most parts can even be printed with a 0.6mm nozzle to save some printing time.
There are a few parts that need special attention though: