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s3d wipe feature and bridging

Posted: Mon Jun 23, 2014 5:17 am
by jimc
since 2.1 there has been a wipe feature added to the retraction setting. i have yet to mess with it. i have sliced and previewed a few models and i cant see anything different being done. has anyone used these setting and have a description of its function? also what length setting do you use?

as for bridging, this is another one i have left with the default settings. do any of you change from the default? what settings do you you and do you find you want to pump out more or less filament while bridging?

Re: s3d wipe feature and bridging

Posted: Mon Jun 23, 2014 4:20 pm
by jsc
Jim, do you mean the Wipe Nozzle setting under Extruder/Ooze Control? That has been there since before 2.1. At the end of a perimeter, when it has to make a travel move, it does a retract, then retraces an already laid filament for the wipe distance without extruding before doing the travel move, to remove any ooze that may cause stringing. It is primarily for machines with Bowden extruders, I take it; I haven't found it necessary for the M2, which has a pretty authoritative retraction. The only evidence of it in the gcode preview will be that some travel moves appear hooked.

I have done a lot of reading on bridging trying to nail down my settings. The consensus seems to be that for the best bridging, you should be printing slow and under extruding. Currently, I'm running 20mm/s (25% underspeed off of 4800 mm/min) and 80% extrusion multiplier. My bridges still aren't what I'd consider optimal; they turn out okay in the end without any dropped threads, but the first layer is always saggier than I'd prefer. What appears to happen is that the hot nozzle causes the previously laid bridge to sag a little, and also causes a shear force which drags on it. I know slic3r has had multiple attempts to improve bridging (see, and it is claimed that Cura does bridges better. I haven't experimented to see if either of them actually works better for me yet. Also, some fan helps, but too much fan will blow the bridges around causing gaps.

Re: s3d wipe feature and bridging

Posted: Mon Jun 23, 2014 5:06 pm
by jimc
Thats real good info jin. Atleast with the wipe now i can keep a lookout to see whats going on. The pet+ doesnt bridge well because its gooey so i thought i would start to tweak and test to see if i can get that tuned in a little better to help. Thanks!