I want a completely rigid spindle with a moving Z axis. I am starting with the openbuilds minimill. I am planning on putting the XY axis on a moving Z axis. I was considering using automotive struts/shocks. Attaching them to a plate with a motor. The plate will have a screw connected to a motor. So the motor can push/pull the plate down into the struts. If I attached that to the Y beam of the minimill I could move my XY carriage up and down, instead of moving the spindle. I would probably have to add a linear rail or something to guide the motion in a straight line. Does this sound feasible to you? Do you think it would be a good idea? It would allow me to have a completely rigid spindle. My spindle would be stationary and the weak point would be the spindle itself. I’m not sure if I’m over thinking this and maybe I should just put the linear rails on the spindle Z axis
Completely rigid spindle, but a completely floppy bed. The weak point in pretty much every single cnc machine (mill, router, printer, laser, plasma) is never the part that actually does the work. The weak point is the machine itself. If this is your first go around, don't try to reinvent the wheel.
If the mini mill is your first machine turning it into a c-beam or something similar might be a good second build. That would give you a machine that would make nice al plates if you decide to go further... There are a lot of builds that improve on the rigidity of the c-beam bed, like this C-Beam Machine Too
