First Layer over support is stringy

[norbert78]

HI forum.
I am printing a camera arm for my MK3s on my MK3s. I am using the settings for simplify3d that can be downloaded from the Prusa website.
The issue that I am experiencing is that the first layer of the parts that is printed over the support structures looks stringy.

As you can see in the following picture, the part of the left part where it was attached directly to the print bed looks fine. The right parts was supported and looks very stringy.

Does anybody have an idea which settings I should tweak to improve this?
thanks
Norbert

[wirlybird]

On the support tab look to the right for the upper vertical separation layers.
I normally have this at 1 for the upper and 2 for the lower.

Your surface from over the supports isn't all that bad.

Another thing you can look at is the print preview to see if the first layer over the support is a bridge (yellow colored). On a small part you may wish to in crease the bridge threshold so it does not create a bridge there but rather a regular layer. It may come out a little better.

[TheBum]

Another thing you can look at is the print preview to see if the first layer over the support is a bridge (yellow colored). On a small part you may wish to in crease the bridge threshold so it does not create a bridge there but rather a regular layer. It may come out a little better.

Conversely, I had a situation where I had a small rectangular gap below the threshold and it caused the filament to be laid down lengthwise across the gap. I reduced the threshold so that the slicer would create the bridge across the gap the short direction and it looked much better.

[wirlybird]

Another thing you can look at is the print preview to see if the first layer over the support is a bridge (yellow colored). On a small part you may wish to in crease the bridge threshold so it does not create a bridge there but rather a regular layer. It may come out a little better.

Conversely, I had a situation where I had a small rectangular gap below the threshold and it caused the filament to be laid down lengthwise across the gap. I reduced the threshold so that the slicer would create the bridge across the gap the short direction and it looked much better.

For sure. Each situation is different and takes some experimenting!
I have had a few where the bridge would not go in the direction I wanted so I created another process for that layer and got the direction with the solid layer but set the extrusion multiplier, speed etc. to create a more bridging type layer. Worked ok.