Used the MPCNC to cut out the circles needed for the flanges and lid.
I used an inner tube as a gasket around the edge of the flange. I routed out the edge so it fits under the clamp ring. It really seals tight. I collapsed the barrel when testing the vacuum. For the permanent one I am wrapping in fiberglass and resin to strengthen it a bit.
3D printed inlets and outlets. Used Onshape, KiriMoto to slice, Estlcam to create code, CNCjs to run it.
Next step is to do the dust shoe. I understand we need to avoid weighing down the z axis. Looking at all kinds of models and variations on where to attach. Might be able to just use an enclosure and have a wide orifice on the spoil board that can collect around the work piece and lie flat on the table. Not quite sure what I will do.