Optimize gap between part surface and support for ABS ???
Dear Community,
since a while I am working with slic3r Prusa edition to prepare my STL-Files for the printing on a Prusa i3 MK2S. If I don`t need any supports, this slicer works very fine. But by generating supports slic3r has always a gap between the first layer of the part and the last layer of the supports (see picture). This gap has the same measure as the used nozzle in the configuration and can´t be removed by the normal settings. Due to the gap overhangs will occur in massive curling while printing with ABS and even sometimes with PLA, so that the quality in this area of the prints is very poor. Therefore, a lot of prints failed, because the parts were torn away from the start plate.
Reducing the z-distance to zero is no solution for me, because I do not use a water-soluble filament, so that the supports are very difficult to remove, when this function is switched on. I also tried further settings like reducing the xy-distance, temperature, layer high, increasing the interface layers etc., but unfortunately nothing helped. 😥
Comparing the print quality with a cheap Tiertime UP-Mini, where no gap is seen between part and surface, the Slic3r parts in combination with the Prusa i3 MK2 are significantly worse.
So, how can I remove this gap in Slic3r to optimize the contact between the part surface and the support without worsen removability. Do has anybody a solution for that problem?
Re: Optimize gap between part surface and support for ABS ???
Coming from the TierTime world myself, I definitely feel your pain.
This is something that's been discussed a few times, and there's a longstanding open issue in Slic3r to fix it. The algorithm that calculates the bottom layer on top of support is just broken.
Here's a couple threads that discuss this: https://shop.prusa3d.com/forum/original-prusa-i3-mk2-multi-material-f26/slic3r-support-contact-z-distance-t14220.html#p70640 , https://shop.prusa3d.com/forum/software-f13/support-contact-z-distance-supported-surface-optim-t14106.html#p64615 , https://shop.prusa3d.com/forum/print-tips-slic3r-settings-kisslicer-model-repair--f12/bad-finish-below-support-material-t6033.html#p48027 , https://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/supports-question-t6692.html
Here's some discussion on Github: https://github.com/alexrj/Slic3r/issues/2930 . This GitHub issue has a bonkers workaround that involves setting a really small nozzle diameter and a large bridging ratio to get Slic3r to do the right thing. I haven't tested it yet, but I plan to: https://github.com/prusa3d/Slic3r/issues/102
Re: Optimize gap between part surface and support for ABS ???
Hello Peter,
thank you for the answer!
I´m glad to see that I´m not alone with that "strange" problem. As I could read in the attached links, increasing the flow rate and reducing the cooling for bridges can help a lot. My first short test showed a much better result today morning. Therefore, I think playing with that settings could be a solution for the bad adhesion between the first part layer and the supports. But of course, more test will be required to prove that statement.
Meanwhile I`ve bought Simplify3D, which I going to be testing the next weeks. I will see....
BR
Michael
Re: Optimize gap between part surface and support for ABS ???
Let me know how Simplify3D works for supports. It used to have a reputation as the awesomest slicer around, but lately I've seen a lot of complaints that it hasn't been keeping up.
You can also try Cura. I was going to try Cura next if I can't get Slic3r to give me good quality supports, mostly because it's free.
For what it's worth, I've been digging in to Slic3r's supports and so far I've only been able to get mediocre quality from it. The fundamental issue, I think, is that Slic3r treats supports as essentially just structures to hold up bridges. So unless you have soluble support, it will always put bridges on top of the supports.
What it should be doing instead is treating the support as a raft that holds the bottom shell (not that Slic3r does a good job with rafts, either). The trick with a raft holding up a bottom shell is you need to extrude the bottom shell so that it rests on top of the raft rather than getting smooshed into it, so the adhesion is minimal. That can be tricky.