Dual extrusion setpoints not working as expected

[anthem]

Hi all. My machine has two extruders and I'm attempting to print a part that uses Extruder 1 for the first 4mm, then switch to Extruder 0 for the last few layers (printing black numbers on top of a different-colored base).

I'm having a really frustrating time trying to get this to work properly -- in fact a lot of dual-extrusion operations I've attempted I've found extremely frustrating.

My thought was that to avoid using an ooze shield for the whole part I would use two processes with temperature setpoints, keeping the black extruder cold until layer 39 when it starts to warm up, so that it can printing at layer 40.

So I set up two processes:
1) Extruder 1 prints up to layer 40 (4mm at 0.1mm layer).
2) Extruder 0 prints layer 40 and above.

I have both processes grouped (differing only in start/stop heights and default extruder) with temperature setpoints:

Extruder 0 (for black digits):
- Layer 1: 0 degrees
- Layer 39: 190 degrees (start warming up 1 layer prior to use after layer 40)

Extruder 1 (base color):
- Layer 1: 191 degrees
- Layer 40: 0 degrees (base color no longer used)

But what I end up with in my gcode is this:

- Init (this is fine, it sets initial temps correctly):
M104 T0 S0
M104 T1 S191
M109 T0 S0
M109 T1 S191
...

; layer 39, Z = 4
M104 S190 T0
...

; layer 40, Z = 4.1
M104 S0 T0

At layer 40, it just turns off the temps that were set at layer 39. It should have turned off T1, NOT T0.

What's going on here? This is really frustrating. I'm finding the configuration process in Simplify3D to be really confusing (I've been using Slic3r very successfully for several months now, including with dual extrusion). I've been able to solve or work around most of the problems I've faced trying to configure Simplify3D, but this one actually seems like a bug instead of just a difference in philosophy.

In this same use case, it would also be nice if the "Wait for temp to stabilize" actually caused the temp setpoints that are inserted to use M109 instead of M104 when making large temperature shifts. When adjusting a few degrees at a time, M104 is fine, but anything >10 degrees can take some time to achieve. If I tried to set my temperature for layer 40 *at* layer 40, it would be attempting to cold-extrude for at least most of the layer and end up grinding my filament away.

[CompoundCarl]

It would help if you could post a factory file for your print. It's pretty hard to guess what's wrong otherwise

[anthem]

It would help if you could post a factory file for your print. It's pretty hard to guess what's wrong otherwise

Here's my factory file and the zipped gcode output from it. I'm generally finding configuration of dual extrusion in Simplify3D to be rather confusing (particularly because temperature settings for multiple extruders are lumped together under a single Material setting -- it'd be easier if you could apply a separate Material for each extruder).

If there's a better way to do what I'm trying to do, I'm all ears.

[CompoundCarl]

This really isn't "dual" extrusion, since you're just extruding in 1 color for the first 4mm of the print, then you are switching to a different color for the rest of the print. You could actually even do this with a single nozzle by just pausing and changing the filament between prints.

But anyways, it looks like you are already doing most of the setup correctly. If you want to use a specific combination of material (for example PLA on the right extruder and PVA on the left), then you have to setup a new material option for that combination. I'm not sure how you would do this any easier, since you can't just select a material for each extruder, because there's lots of things like cooling settings and heated bed temperatures that would still need to be selected.

I wouldn't bother with trying to leave one extruder at 0C for the first part of the print. I would just heat them both up and use an ooze shield or something like that to handle priming. Otherwise, I find the prints can fail a lot, since one nozzle was never primed or preheated beforehand.

[anthem]

That makes sense, but it still seems like the gcode really isn't getting generated correctly here, doesn't it? Or am I misunderstanding how they work?

I thought I'd try out the temp set points for the first time and was kind of surprised at the results.

[CompoundCarl]

The temperature setpoints are for that individual process. So if you want to change the temperature on the first layer of your second process that starts at Z=4mm, then you would just add a temperature setpoint for layer 1 of that process. You were trying to add all the other prior layers together, so that's why it wasn't working.