burn marks on parts

hello there everyone

I noticed in many occasions that my prints get some burn marks into them and I wonder why that happens. In the photo attached you will see that the burn mark was exceptionally evident on those two parts. Why does that happen and what are the solutions for this problem.

I'm thankful for your help.

Do you clean your nozzle off with a wire brush?

Usually it happens because of build up of material on the nozzle and then falls on print.

Some times it happens if the nozzle isn't in correctly and other times it happens because the bed is warped or unloved and the nozzle scrapes the print

You could order one of these and keep it clean and in tune.

https://www.octave.com/p1173433504/Octave-3D-Printer-Tool-Kit-D/product_info.html

I use a brass brush..

Hi,

I have the same problem, though my Nozzle is perfectly clean at the beginning of the print, it becomes quickly dirty and spread some burned marks through my beautiful white prints (Z-Ultrat Ivory) :( No problems with dark colors of course...

I didn't clean my my nozzle since I started printing so maybe that is the reason behind my problems. however, this brings up another issue, if I want to print with another material like Z-ultrat do I have to clean my nozzle first?

I didn't clean my my nozzle since I started printing so maybe that is the reason behind my problems. however, this brings up another issue, if I want to print with another material like Z-ultrat do I have to clean my nozzle first?

The kind of nozzle cleaning meant here is cleaning the outside surface of it so that it gets a clean brass look without any (burned) filament on it.

Use a wire brush and clean the hot nozzle with it.

Other factors for burn marks I want to add:

Random Seam setting in Z-Suite

Fan Setting in Z-Suite

interesting,  the support center only suggests dipping the nozzle in acetone container for some time, but I guess not all materials can be dissolved in acetone.

interesting,  the support center only suggests dipping the nozzle in acetone container for some time, but I guess not all materials can be dissolved in acetone.

Z-HIPS is one of them.. Acetone doesn't touch it..

Other factors for burn marks I want to add:

Random Seam setting in Z-Suite

Fan Setting in Z-Suite

Random seam gives me less burn marks than normal seam. Did you notice the same thing ?

Random seam gives me less burn marks than normal seam. Did you notice the same thing ?

Actually my experience is the other way round, it depends on the objects shape and Z-Suite version.

But I did not test this seriously because I print always with random seam, otherwise my prints get an ugly seam along the z axis (reprap prints look better then).

This works with other slicers for years, but our experts from poland may think they have to make some more 'inventions' and we just continue to find changing behavior between almost every  Z-Suite version...