Well, if we want to, we can compartmentalize the design, so that it's just a collection of subassemblies. Let the ultimate decision be up the the builder, at the time of construction.

For example, screw drive. Making an axis move, whether it is a moving gantry, fixed bridge, or even a hexabot, is simply a matter of turning a screw, and making the nut move. This subassembly could be reused, for all different designs. The details, like whether the sliding parts are made from teflon or rolling bearing assemblies, is immaterial to making the axis move.

My current design ideas are leading me towards a fixed bridge design, upturned so it fits on my workbench more easily. The primary modifications to the basic design are going to be a reorientation of the "lower" bearing, and a counterweight for the Y axis, so the stepper doesn't have to fight gravity. Otherwise, it's just a traditional fixed bridge machine...no big deal.

The basic principles of design are pretty much fixed...it's just a matter of how you arrange the individual objects.

If any of you are programmers, it'd be like designing objects...reusable programming code that can be "dropped" into various configurations...same basic idea.

-- Chuck Knight