Jay Pique wrote:

Hey, anyone got a suggestion for a 16 foot long straightedge? I'd like
to be able to use it for template routing, rather than jointing, the
edges of long panels and boards. I'm thinking an aluminum extrusion
would be the way to go.

You can't get there from here.

You could fabricate a rigid weldment, then have it machined to get a
straight edge, but then you would have to keep it in a controlled
environment to maintain it.

About 15-20K will get you started.

Lew