Its prints without support in the orientation of the supplied STL files.
I print mine with 0.1mm Zaxis
I choose a Wall thickness of 0.8mm for most parts ....
... the Feedback gear was printed using 0.4mm wall thickness
Sand down the guide rails "Slightly" to enable a glide fit, you can even lubricate them with grease from a "Lip Gloss"
I used 25% as general infill, as this is capable of exerting a minimum of 3Kg force.