Cura vs. Slic3r

I started out with my Taz using Cura, as I like a lot of its features and it prints fine detail like lettering way better than Slic3r. However, I noticed a lot of stringiness on my Cura prints. In particular, I couldn’t get the Make Shootout “Fine Positive Features” model to print nicely. Then I tried Slic3r with the medium PLA profile provided by Lulzbot, and the same object printed perfectly, with no stringing. I went through the settings looking to see if I could understand why the difference was occurring, and I didn’t get much. There were slight differences in retraction distance and speed (which didn’t make sense to me; shouldn’t those settings be the same regardless of slicer?), but it didn’t seem like enough to account for the difference.

What I did notice were the Slic3r extrusion width settings in the Lulzbot profile. The numbers there seemed bizarre to me, though clearly they work really well. Can anyone explain to me why these extrusion widths for various purposes would vary so much? Naively, I would have thought that a 0.35 mm nozzle would have a 0.35 mm extrusion width in most cases, but that doesn’t seem to be the case at all. Seems like I’m not understanding some of the fundamental principals of FFF 3D printing. The Slic3r manual didn’t seem to explain this at all. And why do those extrusion widths vary so much with the different layer height profiles?

I’m also really curious as to how the Lulzbot folks dialed in these settings so finely. Cura doesn’t seem to have anything like this fine control, so I’m wondering if it is even possible to get as nice performance with Cura on things like the Make Shootout bridging and fine positive features tests.

I’d be grateful for any insight people can offer.

Triffid Hunter’s Calibration Guide gives good guidance on Layer Height and Extrusion width.

I too have been a bit baffled by the Lulzbot provided Slic3r settings. Its as if the different profiles were done by different people as there is a lack of consistency.

http://reprap.org/wiki/Triffid_Hunter's_Calibration_Guide

Kenny

The varied extrusion widths are a factor of layer height, extrusion rate and speed. While the nozzle is 0.35mm, by extruding more into the same nozzle > layer gap you get a wider extrusion. Wider extrusion leads to stronger walls, etc. For faster prints, a thinner extrusion width (less squish) and a larger layer height will cut down on print time due to the decrease in the amount of layers in the model.

Cura does support fine-grained tuning, but those settings are not displayed by default. To turn them on go to Cura > Expert > Switch to Full Settings > Expert Settings. Once switched, download and import your desired print profile.

In general, we can take a known good slicing profile, and tweak it for better results, one variable at a time. For a new material, any of the existing profiles can be used, with updated temperature settings, a middle-ground layer height and a conservative speed can be set, then further refined variable by variable based on print outcome, desired speed and material/time cost.

Want to improve your prints or improve our print profiles? You can! The secret?

Print often and print alot.

By changing only a variable or two at a time, you can see how it effects the print, and how it can potentially cause other things to change. Maintain the balance on the settings and nudge it in the direction you want to go!

Thanks, Orias! That was quite helpful.

I’m looking at the Cura expert settings (Mac, 14.12) and only see extrusion width in the Raft section. Could you clarify? Is there somewhere else you can go to see the detailed settings?

Also, are you saying that you can import a Slic3r profile into Cura? I had no idea that was possible. Finally, are you saying that if you hadn’t switched to expert settings first, the settings would not be loaded when you imported your profile?

I’m looking at the Cura expert settings (Mac, 14.12) and only see extrusion width in the Raft section. Could you clarify? Is there somewhere else you can go to see the detailed settings?

Basic Tab > Shell thickness = perimeter extrusion width

You can also export your Cura slicing profile, change the values and import it back into Cura. It’s not recommended though, as Curas slicing engine will maintain the balance of the various settings better.

Also, are you saying that you can import a Slic3r profile into Cura? I had no idea that was possible.

No- :smiley:

Finally, are you saying that if you hadn’t switched to expert settings first, the settings would not be loaded when you imported your profile?

When switching from quick print > Full settings, you have to import a slicing profile.

In general- Cura will do a great job of getting you a good print. If you want to muck around with specific settings you can, but I find I get great results when I let it do it’s thing…

Basic Tab > Shell thickness = perimeter extrusion width

As I understand it, Cura has 3 linked parameters (shell thickness, nozzle diameter, and filament diameter) that you’re not supposed to vary independently. So the shell thickness setting would hardly provide the “fine grained” tuning of extrusion width that Slic3r provides.

In general- Cura will do a great job of getting you a good print. If you want to muck around with specific settings you can, but I find I get great results when I let it do it’s thing

The whole reason for my original post is that Cura did not give me great results with the Taz (at least on the Make shootout objects) when I just “let it do its thing”. With the profiles from the Lulzbot web site, Slic3r did way better. There are a lot of things that I like about Cura, but so far on the Taz (with my one roll of Shaxon filament) Slic3r is the clear winner. If someone comes up with Cura profiles that work better, I’d love to see them.

I am not a fan of CURA.

Everything I learned when I started 3-D printing I learned using Slic3r & Pronterface, so I admit I am very biased.

However, CURA just doesn’t seem to print as well.

I find I have much more control over far more variables using Slic3r & Pronterface.
I also find the Lulzbot provided Slic3r profiles for ABS are pretty close to spot on for getting started.

I really tried to give CURA a good college try, but for serious prints, I default right away to Slic3r & Pronterface.

Does anyone have improved HIPS profiles for a Taz5 using Slic3r? I’ve been using the only one Lulzbot provides (https://www.lulzbot.com/content/taz-slic3r-profiles) but still am not happy with the results yet.

Anyone have some settings they’ve had good success with?

Thanks,

-Mike