Hey guys,I have a file containing approximately 5000 3D poly lines and I want to be able to select them all and have them all broken into 500m long pieces.  Anybody know of a way to do this?Thanks!

Sounds like something that would require a custom lisp routine.  What happens if the lines aren't in increments of 500m?  Say a line is 3261.12m.  What happens then?

Almost none of the lines lengths are exact multiples of 500 so I'd imagine that one of two things would happen - either it is divided into 500m long lengths with the last piece being a kind of remainder and less than 500m long, or the lines are divided into equal parts as close to 500m as possible.  From my limited knowledge of LISP I'm confident that the former would be the easier route to go but either would work.

I had the same question as John, but he asked it and you answered.
 
You won't find anything in the standard AutoCAD box that will do this, so I'd suggest you head over to Lee Mack Programming and sift thru the various LISP routines there and see if something looks close that can be modified.  It's going to take a custom routine almost certainly.
 
Dave.