Donald,
You may send any size file-I've got Comcast and it is very fast and I've no email size limits.
Essentially it seemed that to give the most flexibility that the feedrate should vary by the Z depth, but perhaps not linearly. I gave the program an editor screen with a graph of feedrate vs. Z depth. The user can drage a little cursor around and change the shape of the curve. See the attached shots. Remember, the software the gentleman was using did not allow for anything but one speed. If yours already does, this may not be useful. By the way, the program processed a 300,000+ line file in like 10-15 seconds on my PC.
Lance |