Early builders of aircraft didn’t have computers complex machines or exotic materials. They were craftsmen who used their skills in other trades like cabinetry, even bicycle contruction. They became draughtsmen in order to create the drawings needed as the guide to building. An example of an early drafting kit similar to what was used until the early nineties. A hand planar was used to shape wooden parts like propellers which had to be as symetrical as possible.