Stringing Problem  

Re: Stringing Problem

Yuck. Looks like a temperature problem, or a retraction problem to me. I don't know that slicer, but I would fiddle with your temps and retraction.

Re: Stringing Problem

This is to do with minimum speeds and minimum layer times.

The best slicer to use to combat this is Slic3r PR edition. At the moment, there are very few slicers that can handle this issue although tweaking the parameters can improve matters.

Peter

Re: Stringing Problem

Are there certain parameters in S3D I can adjust that would address this problem the best? I will try temp and retraction

Thanks,
Jon

Re: Stringing Problem

I will try temp and retraction

Well, they don't have very much to do with minimum speed and layer times nor using Slic3r, but you try what you wish. If you do find a better solution then please let us know.

I would also suggest that you try KISS, but the feature you really need is not in the current release (it will be included in the next release).

Peter

Re: Stringing Problem

For me, and I experimented a bunch, the stringing was caused by one thing, retraction distance. Also, Cura seems to handle this better than SLIC3R for me. For me, I also could never seem to adjust SLIC3R as much or as easily as CURA.

For retraction distance, for a direct drive extruder like on the MK2, try maybe 2mm retraction. For a Bowden extruder I use 6mm. If this doesn't fix it, try a different slicer.

Re: Stringing Problem

on the MK2, try maybe 2mm retraction.

Only increase retraction above 1mm if you want to encourage nozzle blockages.

In the early days of the Mk2, Slic3r had default retraction of 1.5mm and the most common issue reported here was blockage between heat break and PTFE. As soon as retraction was reduced to 0.8mm, those blockages stopped. (And yes, there is an alternative work-around; I have posted that a while ago).

Peter

Re: Stringing Problem

I appreciate the advice guys. By increasing my retraction distance to 1.75mm I got much better results compared to the original, but still not great. I've included a pic of my updated results. Would the retraction speed play a role in this as well?

I really love Simplify 3D so far and it would be a shame to find that the slicer is at fault here. Between the popularity of the MK2 and S3D, I can't be the only one who is struggling with this combo.

Peter, could you elaborate on what Slic3r offers in regards to minimum speed and layer times that S3D cannot?

Re: Stringing Problem

Would the retraction speed play a role in this as well?

Not to any extent. Extruder speed is limited within firmware to 25mm/s which is probably the value you are using already.

Peter, could you elaborate on what Slic3r offers in regards to minimum speed and layer times that S3D cannot?

Not really; I don't use Slic3r but I have printed models sliced with it. The problem you are experiencing is due to pressure and oozing (ie the flow of molten plastic) when printing very small parts and Slic3r seems to recognise this better than other slicers available and generates code which does not over pressure the filament and then ooze.

The "experimental" Pressure Advance feature within Slic3r also combats this issue but does not quite work as yet; fortunately that slicer doesn't need it to work!

Peter

Re: Stringing Problem

Oh ok. I'll give slic3r a shot and see how it compares. Thanks for the feedback!

Re: Stringing Problem

on the MK2, try maybe 2mm retraction.

Only increase retraction above 1mm if you want to encourage nozzle blockages.

In the early days of the Mk2, Slic3r had default retraction of 1.5mm and the most common issue reported here was blockage between heat break and PTFE. As soon as retraction was reduced to 0.8mm, those blockages stopped. (And yes, there is an alternative work-around; I have posted that a while ago).

Peter

You might want to notify the people at Simplify3D that, because a retraction of 1.5mm is the standard setting. I've been using that setting and have never had a problems. On my boden extruder machines, the retraction value of 5mm or 6mm works great, again with never a blockage.

Re: Stringing Problem

You might want to notify the people at Simplify3D that

Why, I have nothing to do with S3D and would not consider using that produce.

On my boden extruder machines, the retraction value of 5mm or 6mm works great, again with never a blockage.

That is a little excessive for Bowden, with the MM upgrade using Bowden tubes, retraction of 3 to 4mm works just fine.

If you search my posts, you will find the reason why the direct drive V6 requires only 0.8mm retraction and why any more can cause blockages. Also you will find the reason why greater retraction works fine when using Bowden tubes and the V6.

In the early days, retraction was set to 1.5mm which was the same setting used on the Mk1 with the Lite6 hot end.

Peter

EDIT. There is a very interesting article regarding S3d and Slic3r here : http://www.akeric.com/blog/?p=4164