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Stringing and zits

Posted: Tue Feb 25, 2014 2:23 am
by samsfisher
Hi There,

I am trying to print this head using simplify3d but facing problems with stringing and zits. Its quite surprising that stringing doesnt happen within the model but only between support structure and the model. Therefore, it is not a problem of temperature but of retraction. When i observed the printing process, the string happens between the support structure and the skin of the model. The string can be easily removed but leaves a scar or a mark on the model.

The second problem is that of zits. When i dont use start perimeter at random points the zits occur in a straight line but when i randomize starting points small blobs appear all over the model. What parameter should i be controlling for this.

Thanks
Sam

Re: Stringing and zits

Posted: Wed Feb 26, 2014 9:26 pm
by tri-lite
It's a bit hard to figure out those upsidedown photos....but I can share some things I have learned about supports.

I always access the manual support controls found in TOOLS > MANUALLY DEFINE SUPPORTS. But I try not to deviate too far from the regular pattern of supports that are initially generated by the software. You should think of your supports as a network (they will be removed as one large piece) rather than thinking of them as individual structures.

Compare the supports on the left and right side of my photo and you'll see that the supports on the left side are too sparse. For me, that sparse spacing created problems. I also had problems when I tried to decrease the support infill percentage, so I just don't override the software suggestions in that area.

I don't know if that helps, but I'll pass along my tips.

Re: Stringing and zits

Posted: Sat Mar 01, 2014 9:21 am
by samsfisher
Sorry about those pictures dint realize until I clicked submit.

So the problem is stringing is happening within the boundaries as well. I have tried retraction settings as well. Another problem is the overlap between start and end of perimeter. Depending upon whether I use wipe or coast I see either a small hole or a blob(zit) I am unable to get a part with invisible starting points. Am I looking for holy grail or is it possible ?

Re: Stringing and zits

Posted: Sat Mar 01, 2014 11:27 am
by Festus440
I assume this is ABS.
What retraction settings have you tried? On my Creatr I've been using 1.8mm for ABS.
For the zits you might want to play some more with the coast and wipe settings.
BTW what temperature are you running the extruder at?