Influencing the direction of bridges

[freiser77]

Hello,

I want to print the attached factory-file.
When I prepare it for print, I notice in the preview, that there is a very long bridge from left to right.
It could be replaced by a much shorter bridging distance, if it would be turned by 45 degrees.

I have already tried rotating the model, but it is not influencing the bridge.
Is there some possibility to influence the bridging direction (sth. like the infill orientation)?

Greetings

Florian

[mroek]

No, there isn't. All you can try is rotating the model, which you already have done.
This issue has been discussed several times previously, but S3D provides no response whatsoever. As with any other issues people report...

[freiser77]

Do you know if slic3r is doing this better or provides such an option?
I am thinking about switching to some other slicer.

[horst.w]

Other slicers, other issues!
Slic3r-user applaude S3D-support and demonize S3D bridging. It's your choise.

Optimise your bridging (speed, extraction, overlap), there is only one layer (no. 156) a bridge and it is like support for the next (solid) Layer.

Keyboardwarrriors viewtopic.php?f=8&t=2363

"
Bridging extrusion multiplier: If you find that extruding a lot more/less material helps with bridging, then you would set that here.

Bridging Speed multiplier:If you find that printing faster/slower helps with bridging, then you would set that here. One trick I use occasionally, is I'll temporarily set the bridging speed multiplier to 999, then slice my file, that way the areas in which the bridging multiplier is taking place are bright red and stand out in the G-Code previewer, that way I have a better idea of where the bridging settings are occurring.

"

regards
horst.w, GER

[arhi]

Do you know if slic3r is doing this better or provides such an option?

nope, you can't select direction of bridges with slic3r neither and sometimes I really wonder how the selection is actually made. for e.g. torped fanduct slic3r chose to span the longer gap rather then way shorter one, I tried but change the code, and it would always select that "wrong" path, for that particular part while s3d will bridge over shorter edge, way better solution ... now both create identically "bad but usable" part due to lack of cooling on my part but s3d creates imo lot better choices on that part ... on the other hand, I seen other parts where slic3r selected better bridge .. (you couldn't do it with cura neither but I haven't tested it for a while maybe they added some improvements, dunno about crafware it has many options but on first look nothing wrt this)

some "interactive slicing" where you could influence how decisions are made is often mentioned in this type of discussions but is not something easily done. Forrest Higgs was pretty close to it with his slicer but he gave up number of years ago, both on his slicer project and on the whole "improving the 3d printing" thing, removed himself from reprap core team and purchased UP! printer moving his attention to his original project that got him involved in 3d printing in the first place.

So attm, S3D is the "closest" slicer to the "smart interactive interface" we'd like but I doubt even they will start working on it any time soon

[mroek]

I agree with horst.w. Other slicers, other issues. I don't know if the others have better bridge handling, but the options for bridging in S3D doesn't help with the issue that OP has, which is the bridging direction. Sometimes S3D makes horrible choices about how to actually bridge something, sometimes it works flawlessly. Rotating the part shouldn't really affect bridge direction (but sometimes it does), as that should be some intelligent decision within S3D.

[horst.w]

that's right! Optimation doesn't solve the problem, but it helps as well as possible.

The print-direction of bridging and also of support-printing seams to be always the x- direction (on my printer) therefore the long-way of the bridge is lying in y-direction. In many cases, it is recommended to turn the object 45° right or left to shorten the way across the x-axis.

I have print this afternoon an object with only 15 mm bridge, but it was very successful with full speed (print-speed 100%) and half extrusion.
I think it is always better the nozzle must pull out material and the Extra-Inflation-Distance must be set minimum one extrusionwidth. Also important is cooling as well as possible. The pulled out filament must be hardened before it has occasion to sink down.

H.

[horst.w]

... i is very amazing how S3D handles bridging

Two simple examples:

the test -modells

along a axis and turned 45 degrees

[horst.w]

here the table-like object:


here along the axises

[horst.w]

... and here turned 45 °

the tower ist covered first in diagonal direction, followed by covering the middle and separatly the second tower in long-way direction.

That is extremly different to the system of bridging, when the object are lying along a axis.

A second test shows an other methode. There, after covering the first tower in diagonal direction, the middle part and the 2nd tower is covered at once and in long-way direction .
I couldn't find out the reason.