but not sure if that is the right term :)

I've been experiencing those in the last couple of prints (Z-ULTRAT), not a big deal as I would be sanding the piece anyway but I definitely didnt have those before.

Anyone may have an idea whats causing this?



Looks like the retraction settings need to be updated by Zortrax but I'm not sure I've seen any pics of anyone else expierencing that

I see those too every once in a while. The weird thing is that they usually are in the middle of a completely straight section without direction reversal or seam. The head goes along with constant speed and still leaves the blobs… Have not figured out yet where they come from. They also come off very easily (in my case).

Looks like you have "random" seams selected under the advanced menu.

Not in my case…I saw those blobs although there was a straight seam somewhere on the other side

I do print with random seams (have been asking for quite sometime for that feature) and I prefer it to the straight seams. Oddly enough tho I havent seen this much happening with ZABS but i could be wrong..

Anyone from Zortrax about this?

It might be a little humidity on material, sometimes it's the main reason for surface issues. Like those and similar. I have seen those in a couple of models but then not diferent filament diferent time so it's my conclusion.

Not in my case...I saw those blobs although there was a straight seam somewhere on the other side

Andre, I know the blobs you are talking about, and I have seen them on my prints also, especially on earlier software. But this one looks different to them, and I bet the OP can't just rub them off. 

That could be.

Didn’t Zortrax say that the random seam function is still experimental? Maybe the ultrat setting still needs a bit fine tuning.


Are the blobs basically where the random seam is? Or asking the other way… Is there an additional seam on the respective layer that has a blob?

Or you could ask even in a third way…is there a blob on every single layer without another seam? If yes, then it really seems to be the retraction timing of the random seam.

Hi, I had a similar problem. If these spills occur only in one axis, it can be about the stability of the desk. In my case the use of several steel brackets solved the problem.

I havent paid too much attention where eaxctly on the print they were located, I sanded them off right away (and very easily) . I exclude the stability of the desk, first because the printer is on the floor when it has always been and Ive never experience this before the last couple of prints. I 'd guess that the random seams could be the cause but I will have to see when I print again (which it will happen soon)

thanks for the answers though, still it would be nice if anyone from Zortrax would have any more info about this?