Ooze Shield Alternating extruders when set not to

[Nepherael]

Hi guys,

I've got an FFCP clone and I've started using the dual extrusion. For my current project my color change is height based. Here's the issue:

I was having oozing issues and I decided why not just cool off the extruder I'm not using for the first half of the print after it does its prime line. However, when setting up multiple processes, whether I use the dual extrusion wizard or not, the ooze shield setting is ignoring which extruder is set to build the ooze shield and alternates regardless (which grinds on one of the extruder's filament since it's cooled to 150C after the first layer for half the print). My only solution so far is to use the checkboxes for "Start/Stop Printing At X Height". However, there is a direct setting in the ooze shield that allows me to set which extruder to use for it and that should work correctly.

After some extensive testing I can't really find what's wrong. I have the "Auto-configure for Extruders" set to both on each process (but I ungroup and change which extruder is used on the ooze shield). Is there a way I can set the first process to right and the second process to left and have it work correctly? I have attached my dual extrusion profile. I received this from someone on Thingiverse and I was told it is the product of extensive Qidi testing so I've used a derivative of this profile for all of my printing profiles. The only part where I'm a bit lost is in the scripts section but I would think that wouldn't be an issue when there is a direct setting in the ooze shield section.

I would prefer not to solve this by using one extruder as this issue is bound to crop up again when trying to dual extrude something not height based.

[brian442]

The only time the ooze shield extruder alternates is if you are using multiple extruders on the same or alternating layers. If you are using the same extruder for 10 layers or something like that, the ooze shield extruder stays the same.

Do you have large numbers of layers where you are only using a single extruder? Does the ooze shield stay constant during that section?

[Nepherael]

The only time the ooze shield extruder alternates is if you are using multiple extruders on the same or alternating layers. If you are using the same extruder for 10 layers or something like that, the ooze shield extruder stays the same.

Do you have large numbers of layers where you are only using a single extruder? Does the ooze shield stay constant during that section?

Yes I have 60 layers with 1 extruder being used. It tried to alternate throughout that entire period despite being set to use the same extruder it was printing with. Until I checked the boxes "Start/Stop at N Height" did it stop alternating

[Nepherael]

It's just one color for 60 layers, then the second color on the other extruder. However, I am using a profile with the "Auto-Configure Extruders" option set to Both. Should I set one process to left and one process to right extruder? Is that why it's automatically alternating even when I'm setting it not to?

I don't like that as a solution because if I set each process that way it won't prime both extruders at the the beginning of the print. However, if it starts to work correctly, maybe on that first layer for the second color it will print the ooze shield first. I guess that could be enough to prime it.

That's the only setting I could figure was the problem before, it's just not a viable, or I should say correct, solution in my opinion.

Edit: After some further testing. It only alternates on the base color. the first 60 layers are all supposed to be the right extruder but it alternates. The next 12 layers (60-72) are just the left extruder and it does not alternate.

Is it trying to keep my left extruder primed?

[Nepherael]

Figured out the problem. It's a weird one. Once I learned that I could see which toolhead was active via the drop down I was able to rapidly change settings and check them in the preview (mine was always set to show speed)

Original issue: Process 1 was set to Right extruder for the ooze shield (first 60 layers), process 2 was set to left extruder (top layers). Even though it was set like this the base color was alternating the ooze shield extruder throughout. The only way it would work this way was if I used the checkbox "Start/Stop at N Height".

What made it work correctly was changing Process 2 Ooze Shield Extruder to "All Extruders". If I changed both processes to All Extruders this worked as well but if I changed Process 1 to All Extruders and kept process 2 set at Left Extruder it would still alternate on the base color.

I don't know what would cause this issue at all since the point of setting the extruder is to tell it which one to use. I'm assuming that setting is designed for both processes to be set the same instead of different for using specific extruders or filament for an ooze shield because when I set them both to left or right that works correctly also.

If anyone see this and wants to recreate it the issue I'd be interested in hearing your findings.

[Nepherael]

It's still weird. It works but if I preview it layer by layer each layer is a separate piece of what should be there for the lower part. Like one layer will be empty, the next layer will show the ooze shield, then the next layer will show a layer for that model, and then finally a layer will show with the model and ooze shield before the next layer shows blank again.

Because of this weird issue I set the extruder temp to heat up on a specific layer and it didn't for some reason (this ended up being on one of the layers that shows empty) so my filament broke off in the extruder when I noticed it.

For reference, the top part, the second color, each layer shows correctly. The layer shows the model layer and ooze shield. The only problem is the base color which is separating each item out and showing blank layers (which means it's creating weird G-code as well)

The only setting changed from my original file is that the ooze shield is set to use "all extruders" now.

1st layer - model Z=0.2 - Actual layer 1
2nd layer - Ooze Shield Z=0.4 - Actual layer 1
3rd layer - Empty Z=0.4 - Actual layer 1?
4th layer - model and ooze shield Z=0.6 - Actual layer 2
5th layer - model Z=0.6 - Actual layer 3
6th layer - ooze shield Z=0.8 Actual layer 3
7th layer - empty Z=0.8 - Actual layer 3?
8th layer - model and ooze shield Z=1.0 - Actual layer 4

The only reason I know which actual layers some of those are is by seeing which ones are infill or solid.

What is that all about?

I will also add finally that this ONLY happens when setting up multiple processes. I have been setting testing the ooze shield nonstop with single processes as well and it slices fine... It's also the only profile that shows a layer at Z=0.2. I don't have any offsets set but for some reason all other setups show first layer at Z=0.4

Edit: This issue has evolved quite a bit.

Whether I use ooze shield or not I get the blank layers. Whether I configure for both extruders or one I get blank layers at weird heights. The only constant seems to be when running multiple processes.

Anyone notice this at all? Now that I've got the ooze shield working it shouldn't be a big issue except if I do a temp change and it happens to be on one of the blank layers my printer doesn't change and then grinds my filament to dust. On top of that the heights are really weird with the blank layers and regular layers.

[Aha]

I have the tiniest piece of the puzzle I think? At least in my case, I'm printing a piece with a few base layers before it goes to both colors. S3d only does every other layer for each color if you have it set to both, but ignores those layers if you're only doing 1 color. So you have to print ooze with only one color up until you start both or you miss spots (at least that's the behavior I'm seeing).

Definitely a confusing mess though. Looks like I'm running into similar issues to you. My only question/concern is that not everyone is dealing with them so it's quite confusing. I'm on the lulzbot taz 6, but this seems like how it slices more than anything else. Wonder what we're doing that's unique.

[Aha]

I found a possible reasoning and only partial answer! The problem lies in how s3d does things off the wizard vs NOT. I was having this problem and others after setting up just 2 profiles. After reading a bunch of threads similar to this one in substance, I decided to nuke my profiles and reload from the wizard. It magically worked! (well enough anyway that problems described here disappeared)

Even though it's exactly the same processes, s3d is somehow doing different linking of them when done through the wizard. And I think it seems to be PER MODEL setup. So if you get it once, you may have to start from scratch with the wizard and processes (normally I've just been using the same profiles then tweaking each time instead of reloading anything). When I redid from scratch, suddenly it stopped missing layers when it was only one color and properly printing the ooze shield before printing that color (still need to fix other retraction issues though).

So with your evolved problems, I believe that it's because s3d doesn't play nice with additional profiles thrown in and doesn't set it up to do proper order of operations.

There IS one suggestion I could give you if you need multiple processes though: try figuring out how to use the "group processes" feature for additional settings - or try using the wizard again? I think there's hidden code or a glitch making it so you need the wizard and/or grouping to make it properly work - and won't work even if it looks like it's fine if loaded differently!

Hope that works, I'll keep working on it, but I don't know that I'll get that far on mine for a while yet!

[Nepherael]

Thanks for following up on this!

I know when I was creating my processes some time ago that there was a reason I decided to stop using the wizard. However, I'm willing to go back and try the wizard again and tweak my processes from there.

When creating these processes there are certain settings for me that must be different so I have to keep ungrouping them to change matched settings. I have some ways I can think of around this that will allow me to go through the wizard without having to ungroup and regroup afterward.

I will report back once I have an opportunity to run through this again. Thanks again.