Issue when generating the prime pillar using 2 processes

[FlashErase]

There is an issue with the prime pillar when using multiple processes for one printjob.
The goal: printing an object with ABS in tool0 and support with HIPS in tool1.
I generated a single-profile-process "sample_1.factory", where the prime pillar was
sliced correct with alternating tool0- and tool1-layers:


Because the upper part of the model has no support, I want to stop the prime pillar
above 49.28 mm to prevent the waste of material and generated a second process
without prime pillar above this height while stopping the first process at this height
"sample_2.factory".
From the moment, the second process was created, the prime pillar in the first
process was sliced by using tool0 only. Tool1 was primed nevermore. This is completely
independent from the settings in the second process. The support with tool1 was
generated correct but without priming. So the problem can not be caused by deactivation
of tool1 but by the slicing for the prime pillar:


In the third factory file I simply deleted the second process. Now the prime pillar was
sliced correct again. But of course the upper part of the model is missing:


Here you can see the printed model (with the material wasting prime pillar):
http://www.thingiverse.com/make:200613

[Kwejk]

I can only confirm the issue. Using to processes is a workaround the slicer is not happy with.
A setting for prime pillar hight would be optimal.

[TrevorPhilips]

Prime pillar doesnt work in S3D with many tools.
Make a dedicated primepillar (completely different model) for every tool and mark " Layer/Print islands sequentally.."
Thats how I got it working.

[FlashErase]

Thanks for your hint. But how I can make sure, that the separate prime pillar is printed before the layer in the model
in any case?
Especially if the first tool is ready with its layer in the model I fear that then the layer for the second tool within the
model will be printed immediately and the prime pillar only afterwards.

[FlashErase]

It seems that I'm to stupid. I added two prime pillars and processes. But when I slice it with S3D these pillars are useless,
because they are in the most cases printed after the associated model layer. Any hints to guarantee that the prime pillar
is always printed before the models layer?

[KC_703]

I could be mistaken, but the ooze shield feature prints an outline (skirt) before the layer which also acts to prime.

From the print simulation it looks as the prime pillar should print after the tool change and before the layer... simulating in the preview mode seems to confirm this.

[FlashErase]

The ooze shield may be a workaround but wasting a lot of material. And because there is a long way in
the begin of every ooze shield line without material the whole shield becomes instabil. To prevent this,
the shield muß be drawn with two lines wasting even more material.
In my last attached factory-file is to see after slicing, that the additional prime pillars were often drawn
after the model layer and so the model layer starts empty until the material flows again.

[KC_703]

Waste of material... so is the prime pillar for that matter... I've learned to just stop being petty with filament, just have plenty on hand.

Check your retraction settings, sounds like too much retraction if the hotend needs more than a few millimeters to prime. If the retraction setting is a direct relief for ooze, then maybe its also your extrusion temp too high.

Or play with the "extra restart distance" setting, which should help prime the hotend. Use small increments, +.1mm...


EDIT: I mentioned earlier in the thread that the ooze shield prints before the actual layer... that doesn't seem to be the case after watching the layer print in Octoprint's G-Code viewer. So the "extra restart distance" may be the best way to prime the hotend after a tool change.

[FlashErase]

@KC_703

Thanks for the hints. But there are not much variance left for me. I tried to optimize these parameters for best layer filling and minimal oozing. So I'm afraid that my only possibility at the moment is a fat ooze shield unless S3D will fix this issue with the prime pillar.

[KC_703]

Yeah, it looks like the prime pillar should print before the layer... and it doesn't seem to be doing so in actual print.

Luckily, I'm not having issues priming the new toolhead. I've stopped using the prime pillar and only use the ooze shield, which still prints before a new layer after a tool change (again, luckily no tipping ooze shields from lack of priming).

EDIT: I'll have to try the prime pillar again and watch the print in the gcode viewer more carefully. I'm pretty sure they have the ooze shield and prime pillar printing in reverse order...