Group, I plan to mount my plasma cutter in a fixture in such a way
that I can feed 4130 tubing under it to cut saddles.  The tubing
would rest on a receiver which would allow me to move it in and out
and also rotate it.  I don't plan to follow templates, just silver
pencil marks  the same as I do now when grinding the saddles. The
advantage would be that the cut would be perpendicular to the wall
(grinding and all rotating tools make feathered edges), it would be
very fast and much cleaner than grinding.  Does anybody see any
reason why this would not work?    Jerry

Sounds like a great idea Jerry. You could make paper templates  using 3D and
transfer the curves to the tubing with silver pencil.
-- 
Paul Lamar ...No rotor no motor.

Paul,  considering a complete engine mount with numerous clusters,
how difficult would it be for you to provide me with such templates.
It sounds like a major undertaking.  The problem is I seldom (so far
"never") build the same mount twice.    Would the files be graphics
or CAD?  Could you send me one as a test.  Thanks    Jerry

It would be a lot of work. I am not volunteering :)
Now if you want to buy Rhino and a PC I can send you the mm files
and you can do the templates. The scale templates can be printed from
jpg files using the screen capture trick or printed directly
from Rhino. It takes about two or three minutes for each template.
A six tube motor mount would have 12 templates. It is kind of repetitive and
tedious work.