this might be a stupid question or a brittiant invention, and there and jigs or clamp type mechanism that you can place the plasma cutter inside and easily cut a straight line, or easily cut a tube evenly. just thought it would make life easier.

 

hold a straightedge up against the metal your cutting and drag the nozzle down sliding against the straight edge.

or go baller like the one we have at work that cuts out whatever pattern you put in it

 

but what about piping, is there no tool that locks the nozel in place then you slowly spin the tube yourself.

 

Make it!

 

It's called a vice :P

 

You can buy pipe rollers that have a little motor at one end to spin the pipe around while you cut it or weld it.They are kinda pricey though as the one we use at work was around $4-500.That and a magnetic straight edge for flat cuts works great too.