One more thing. Tried twice over the weekend with a 3 hr print and it failed both times after prompting to change filament, then hitting "continue print" under the sdcard option on control box. I tried a small 1" x 1" x 1/2" high test print with the newly added "change filament" code per the line above and it worked fine, so I ventured into the larger print. Now it goes all the way and prompts to change filaments (actually just goes to 0,0 which I know means to change the filament as its the correct layer per the script line I set), then I change it, and then choose continue to proceed with rest of print. It goes thru all the motions fine but the only thing (and most important thing) is that it IS NOT EXTRUDING the filament. It did extrude fine with the test print but not with the larger print, which has a higher z value. ???? Not sure why this is, must be something in the slicer S3D causing no filament to come out. Any ideas???