Apparently your references on the characteristics of titanium do not follow my references. My references indicate that titanium has a density that is about one half of copper and about 60% that of iron.
For it's weight is very nearly six times as strong as aluminum and twice as strong as iron. So taking these into account for a equal dimension of material titanium would have 60% the weight of iron (which is very similar to stainless steel)...So computing this to arrive at the same strength we would have a componant that would be 30% the weight of iron or stainless steel. Further more at that it would be six times the strength of an equally sized dimension of aluminum. So arriving at the same structural strength you would be able to decrease the structural dimension of a titanium componant to 16% that of the size of an equally strong piece of aluminum. This decrease in dimension to achieve an equal strength more than offsets the higher weight per dimension of titanium over aluminum. That is what my resources and my math indicates.
Furthermore it is born out by my son who is a metallurgist and production engineer with Boeing Aircraft Company. Dimensional stability of a metal is a condition of it's characteristics insof as being a conductor or insulator. Stainless steel is a far less efficient conductor than a metal like aluminum or copper. This relatively poor conduction property leads to problems with dimensional stability when one is welding light guages of this metal (stainless steel). I strongly disagree with your statement about light guage metal being more easily welded with MIG rather then TIG. TIG with a continually variable amperage control allows one to alter the current over a range and gives much better control of the welding process.
All, (read that to mean each and every instance) of the light guage stainless steel TIG welding that I have observed in over thirty years has been DC positive current. The only instance of negative current TIG has been on Aluminum. I agree that hi freq (alternating current) is not necessary to the welding process once the arc is struck. However when you do welding on really light guage metals like beer cans then the hi freq does help one heck of a lot.
I have personally welded stainless with AC TIG and I have welded stainless with DC positive.(electrode positive) By the same token I have welded aluminum with TIG reverse polarity.(electrode negative)
I agree that titanium does carry special considerations when it comes to machining. But by optimizing feed rates, chip loads and the flute orientation of the end mill one can come a long way to achieving acceptable results in the machining process of this metal.
I am fully aware of CNC controlled wood working equipment. My remarks about using a machine for both metal and wood was aimed to the reduction of an investment in machinery for someone who opts to try to build their own metal camera and who presently owns no machining equipment.
I stay by my earlier thoughts on this subject.