This is a short post about how, roughly, the thinking process goes for figuring things out for this machine.

I prefer to go from top to down - I guess its a habit I picked up probably when I worked in engineering bureau during my masters studies doing autocad drawings for housing construction. All the forces must hit the ground eventually in housing construction after all ... And CNC bench is abstractly speaking just a small construction with moving parts.

So this means I'm starting from z-axis. First just roughly drafting up how small can I make the plate which should end up holding all the useful stuff with the lead-screw and linear bearings attached to it. Then how that z-axis plate would be related to y axis, then how y axis is associated with x and then it's basically all figured out. It is kind of iterative process with a lot of moving around blocks and stretching and rotating for getting the geometry more or less figured out. After all that is done then will be the part where I will make it as rigid as I can within the constraints of remaining space....

This is the current draft with the progress I did this evening after I got the daughter to bed. And this is how the z-axis plate would look in autodesk inventor. With the linear bearing blocks and the lead-screw nut attached to it. Pretty crowded but should be functinal enough.

Once I get this version of the machine properly figured out I'll do some rough math about deflections and so on but probably the final test will be the reality once I get it all done.

Current dimensions of the z-axis plate are 130 mm wide and 100 mm high. It will have 120 mm of potential travel space between the horizontal plates (total distance 220 mm) out of which I plan to use about 80 .. 100 mm for actual z-axis movement range.