A tool change doesn't trigger the tool change scripts on each layer. It is in constant. Look at the preview in Simplify3D. It shows you that it is inconsistent.JoeJ wrote:You don't need different scripts for the different extruders. Use the same script for both. A tool change occurs on each layer, so as long as both extruders are using the same tool change script and drawing their lines in the same place, it will be fine.
My tests in Simplify3D 2.2.2 show that the first and last layers get drawn TWICE in this case, so we get 2 tool changes for the 1st layer, not 1. It's buggy. Try offsetting the two G-codes just enough to see each process's separate line and where they intersect with each other. The object builds with the first two processes making a single line at the same Z level, from there on, each line is printed every other layer, or 1 tool change per layer, and then again near the last layer, 2 again are printed at the same Z level. So it switches between 2 tool changes per layer, to 1 tool change per layer, and then back to 2.
It should be doing 2 tool changes per layer, not 2, then 1, then 2!
It's tool change script triggering logic is all goofed up. But drawing two lines in the same location twice doesn't cause much of a problem, but it can contaminate the extruder's nozzle with the other extruder's filament as the filament bunches up as it's printing over a layer that has no space for it to print because it's already filled in.
A future release of Simplify3D is bound to fix this weird tool change script triggering behavior. So don't rely on this weird behavior not changing. It most likely will change.