Hi All, I tried to fight a problem with my prints about diagonal unwanted strings on my print when the head is traveling to a new starting point. It is very annoying ( i don’t need to explain i guess), so i thought to go into the Cura retraction settings and change the values so that the head will lift a bit when travelling. But i’m not sure the change has any effect (from visual point of view it hasn’t), now i read that in Cura you should change the gcode flavor into RepRap. I wanted to check with you ladies and gentleman whether this is the way is to go before printing another object for the bin ;-)… your opinion is appreciated !! other tips too
Don’t have your setup, but stringing is unlikely to be due to the gCode flavor, but it may give you access to more configuration options in Cura. Suggest you take a look at this. Great guide for several different issues.
https://www.simplify3d.com/support/print-quality-troubleshooting/#stringing-or-oozing
Hmmmm, maybe a picture would help? However, I strongly doubt that your gCode flavor is the problem. Instead, I would try looking deeper into the Cura settings. For example, the head lifting trick is called “z-hop”. You could try and increase your “z-hop” distance, this raises the nozzle even more. You could also try and increase the retraction distance. This will retract the filament farther into the nozzle before moving the nozzle. Also, (I know this sounds dumb) make sure retraction is enabled! It is possible to just uncheck the retraction box.
I hope this helps! Retraction is definitely a tricky problem. However, I don’t recommend changing your gCode flavor until you are absolutely certain that it will work. Good Luck!
Jackson
Ooops! I also forgot to mention something rather important! As you are probably well aware, Ultimaker 3D Printers use a bowden extrusion system. This means that the filament feeder is NOT connected to the extruder. This allows for a lighter print head, and quicker speeds. However, the downside to a bowden extrusion system is because the filament has to travel such a long distance to the nozzle, the bowden feeder has to pull extra hard backwards to avoid strings. However, in the default version of Cura, Ultimaker doesn’t account for this long distance, and the retraction distance is set to that of a normal extrusion system (where the feeder is on the extruder). This is why it is extra important to increase the retraction distance.
Sorry I forgot to post that in the first post, but I felt this was pretty important to mention in your problem.
Thanks for the useful responses. I also post some pictures here.
What i can tell is that on one site it seems the bed is to high and hence the previous layer is hit when making the travel to prepare for the next layer. Although i’m pretty sure i leveled the bed according to the UM instructions video. The reason to mention the gcode flavor is that in another forum someone mentioned that ulticode will not override (all) machine settings and hence i thought the changes i made on cura didn’t effect the print et all.
retraction settings:
min travel (mm) = 1.5
enable combining = all
min extrusion before retracting (mm) = 0.02
z-hop twhen retracting (mm) = 0.075
I cannot see where to set the retraction distance (except on the machine itself).
i’ve likely two issues . one is scarfs the other is strings/oozing.
thanks
That looks like a very small z-hop to me - just a fraction of a layer. Any ooze will end up dragged across the face and you *may* even get some remelting as the head skims over. I personally use .5 mm z-hop and haven’t seen a gain to make it worth lowering. I also use a 5mm min travel, but that shouldn’t matter for what you are showing.
Yeah, I would definitely try increasing your z-hop based on your pictures. Personally for a Bowden extrusion system I would use a .7mm z-hop (that might be overkill).
I hope this helps!
Jackson
Significant z-hop increase did the trick indeed. I was a making small changes and didn’t know bowden extrusion requires way more z-hop lift compared to Cura’s suggested 0.075.
thanks folks, for your support !
