The fundamental issue:
Metric or Imperial
then we need to add tolerance
The original design (V1?) already mixed it up with the bolds and nuts, M8 and 5_16, M3 / M4 vs 6_32. Being from Europe in a big city i can source the Metric parts easily (just round the corner in some hardware stores) Imperial becomes a bit more expensive, and time consuming option (i need to order them).
Same as for the Conducts/Tubes/Pipes
Coper, Aluminium or Steel, Metric or Imperial, i can order impirial, but if i go to the local hardware store….. i’m stuck with 22mm (dirt cheap) and if i get 25mm it might be close to 25.4 depends on the store/the batch and tolerance.
Example : i printed the International version of the Roller, to find out that the rollers (bearings) and the 25 mm Aluminium pipes don’t fit properly, there is around <1mm space.
So for V2 i would say that there is a need for some tolerances in the (great) design.
ps: i’m still in printing phase…..