Vulcan Large CNC

This is really the heart of the whole system. If this is advanced enough, it can handle a whole range of operations.

The head can move in cartesian coordinates as well as tilt 180° in two axis.

Movements don't need to be particularly fast, but they do need to be precise. So it will probably be rigid, so it will probably be heavy.

For CNC milling, automated tool change would be a good target. Even better would be changing the entire head - allowing for combinations of additive and subtractive processes.

As Primary Workbench

The large CNC surface will also be the workbench surface. While the dimensions are adjustable, it will be around 4x8 or 4x4 for most US users. The top is a sheet of MDF designed to be replaced regularly. Immediately below that is a torsion box.

I think the way I want to do this is to have electrical conduit bolted to the frame. The guides will be 3 points, avoiding the bolts. Opposite the bolts, we'll attach a rack gear right to the rail. Initially this can be 3D printed, but once the cnc is up and running, we can mill it from aluminum. With a welder, this could be welded right to the aluminum conduit.

The entire CNC machine is built into the gantry. It can be entirely removed.

Dust Collection

Nothing special but there should be a shroud with a vac hookup.

Random Ideas

3D Printer Head

Not just a hot end, but a full 3 axis printer. The idea being that the large machine could slowly position the 3D printer, then the 3D print head could move quickly.

Rotary Y

Make the Y axis primarily a rotary axis - like a CNC lathe. For milling, a rigid surface is connected with helical gears like a 3D printer bed. This would also support adding a belt for better automation.

Or a gear train could a lead screw for better precision.

This also has the advantage of making the core of the machine very compact.