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.


Jerry,
That will work great. I have had tubes laser cut using a 4 axis laser system
to do the same thing. The squared up edges make a far better weld. Even in a
manual system, you could do hard templates on a larger piece of tubing, and
clamp a guide pin to the part you are cutting. This would allow you to
replicate a cut very easily and make your parts very `. If you want
a drawing on how to do this, let me know.
Larry

Jerry,
I have been trying to think of any easy way to do those elongated notches,
but for the life of me I can't. As Larry said the laser would be the best,
quickest but most expensive. Next would be the new CNC plasma cutters, not
as expensive to have done as the Laser but nearly as expensive and all too
expensive to buy for your needs. Also leaves some slag to clean up.

Then there would be the small CNC ( digital readout) Mill, probably more
than you want to outlay anyway. So I guess you have looked at all these
options.

The punch notches are the quickest and easiest, but I don't know if you can
buy special punches - I guess you can but would they be cost
effective.Perhaps there is a manually held punch nibbler, that nibbles away
at a predetermined sized and you could finish off with a belt sander. I
believe that would be my preferred option.
George (down under)

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