Welcome to the SeeMeCNC Community

Hi,
So, I was printing something with thin towers and netted myself a lot of horrendous stringing. Most note-worthy is the fact the stringing was on the side from which the hot-end came as it moved from tower to tower. There were four towers forming the outline of half a hollowed cube. The strings came from one side of each tower in a counter clockwise fashion. After close observation, I noted that right before the head got to each tower, the hotend would emit a little bit of material that would hang on the nearest corner and it would build up higher and higher.

I went ahead and turned on Wipe Before retract. That helped a LOT, but only for ONE tower! The other three towers still exhibited the stringing symptoms. So, that got me thinking more about another setting in there called Min Extrusion Requiring Traction. That appears to require X amount of filament to be extruded before it will even consider retraction. So, to me, that is a "trigger" for the wipe, right? I think it goes a bit deeper than that however. If you are printing coarse layers, it will hit that trigger faster than if you were printing very fine layers because you are moving more filament. The thought here is that I may need to change the Min Extrusion Requiring Retraction if I am printing fine (0.14mm) narrow rail-like towers because it will take a lot longer before that trigger gets hit to execute the wipe. If the trigger doesn't get hit, then it doesn't wipe except occasionally, thus the weird behavior.

Good to conjecture, but need to turn it into theory. I will experiment and post the results.

Any chance that your nozzle is tilted ever so slightly and it's wiping differently at different angles because of that?

I'd also be curious what would happen if you rotated the object and/or your infill angle. It's possible that you're just noticing the start/stop of each layer being in the same place.

Good question. I am printing a different object at the moment, but I have already notice that it is wiping a LOT more since I changed the Min Extrusion Requiring Retraction to 0.75mm down from 1.5mm. Virtually all of the budding has gone away and not seeing any stringing....but then again I am not making thin rail-like towers so there is that. It takes a little bit longer for the wipes, but man, it's nailing the prints and they just keep getting better. I am printing at 0.14mm with a 0.5mm nozzel. Not yet brave enough to go down to 0.12mm or 0.1mm.

I also slowed down the initial layer print from 12mm per second to 10mm per second and also recalibrated the Z a little lower and the bed adhesion is orders of magnitude better!