9

Retraction is the reversal of the direction of the filament and is generally used when moving from one non-contiguous point of the print to another, in order to prevent stringing and oozing of the filament. If retraction is not employed then the filament still coming out of the nozzle, after the last point was printed (and paused), will stretch, thus ...


7

Yes, if you are using the Combing Mode option, please ensure it doesn't do this in the skin, for a leak/string free first layer, it is required to set the Combing Mode to Not in Skin. When the mode of the option is set to Not in Skin, combing is "off" for the skin; this implies that the material will retract and move in a straight line to the next print ...


7

Cura has a setting called Combing that is enabled by default. This stops the printer from retracting if the travel is contained within the walls. It does this to speed up the print but you get oozing during the travel since the plastic is still in the melt zone. You can change this setting to no skin which will stop it from combing on the skin layers or turn ...


5

The Monoprice Select Mini V2 uses a Bowden style extrusion system. Bowden extruders compress the filament in the tube where the gap between the filament and inner tube diameter allow for the filament to buckle slightly and compress causing a pressure build-up in the hotend. Without retraction this implies that the filament will start to ooze out of the ...


4

You probably have the "Combing Mode" option under the "Travel" options enabled for each layer (All). Combing reduces print time by leaving out the retraction, but leads to ugly first and top layers by leaving "scars" on the surface. It can be disabled by excluding the bottom and top layer by changing the setting to Not in Skin or for all layers by choosing ...


4

Fighting stringing will not work by increasing the temperature of the hotend. There could be 2 possible causes for your problem, the first is that you still have a too high retraction speed, too high for your stepper to follow (do note that the default value in Ultimaker Cura is 25 mm/s), the second is that you retract too far and the cooled "hot" ...


4

You cannot endlessly increase the retraction distance, doing so leads to different problems as you encountered. As a rule of thumb, the retraction distance should not exceed the length of your nozzle. Depending on the type of extruder, many printers use a value between 2 and 7 mm (e.g. the Ultimaker Cura retraction length is 6.5 mm at 25 mm/s, ...


3

There's a bit of a compromise here: Filament cohesion in the nozzle isn't strong enough to remove all residue at higher temperature Extruder motors can't get sufficient grip / don't have sufficient torque for filament extraction at lower temperatures That means you'll always have to purge some of the old filament when changing to a new filament. To easily ...


3

The slipping does result in lost retraction distance. It does not result in underextrusion, lost material (except possibly via having insufficient retraction after the reduction), or anything like that. If your retraction is set to 6 mm, but the bowden pulls 2 mm into the coupler when you retract, those first 2 mm of filament motion do not pull the filament ...


3

You retraction settings may be too high. Direct drive extruders require less retraction than Bowden style extruders. Typical retraction settings for direct drive are 1.5mm at 50mm/s and for Bowden, 4mm at 50mm/s. The speed usually makes more of a difference than distance beyond a certain point. You can get away with smaller retraction settings if you ...


2

What I ended up doing was using the settings from the cat.gcode that came with the printer. It has a retraction of 10 mm specified, which I thought was a bit much, but if it works, it works.


2

You can Z-hop what you like, but if it is oozing it is oozing, you will always see the effects of that as it just drops down. Basically you have multiple issues, first the oozing, second the line markings on the top. First Oozing is fought by applying correct settings for e.g. print temperature, retraction, coasting, travel speed, as is explained in an ...


2

If it's just the pressure fitting on the brass coupler that shifts in/out, or the PTFE tube shifting slightly in/out but remaining in the coupler, that shouldn't be a problem unless it's so loose it can come out entirely. The blue clips which should have come with the printer are intended to stop this motion or at least provide enough pressure to prevent it ...


2

I found this post on the S3D Forums that seem to have some interesting information on custom scripting within Simplify3D. While this doesn't seem to SPECIFICALLY address the question you've got, it looks like there's a "Retraction Scripts" tab that you could probably leverage your T2 tool inside of, using "OLDTOOL" instead of "NEWTOOL". For additional ...


2

Consider that the string you are seeing is the nozzle wiping across the surface, especially if you are not getting stringing via your test part. As you suggest, it's not unlikely that the layer viewer is showing movement and not extrusion. Check your z-hop settings as well as the other references in the linked page. Z-hop will drop the bed by the set amount ...


2

It's likely that you're hitting Cura's Maximum Retraction Count (retraction_count_max) within the Minimum Extrusion Distance Window (retraction_extrusion_window). This is a misfeature supposedly designed to avoid grinding/flattening the filament, but of course acting on it will ruin your print in exactly the same way you're seeing. I think setting the window ...


2

The travel speed of 160 mm/s is a big red flag. PETG is not tolerant of a hot nozzle moving over it at high speeds, especially unretracted (combing). The nozzle will drag material in a stuttering pattern, every so often, marring the surface and pulling what it dug up into strings. Lower the travel speed to the same as the print speed, and then experiment ...


1

What you are seeing is what is called the 'seam'. Since this part cannot be printed in vase mode (where the extrusion is essentially done as a compressed spiral), there is a point where the printing on a layer ends, and the printer moves to the next layer. This is where the seam is formed. Blobs that form at this change in layers are not uncommon, but the ...


1

Minimum Travel after Retraction is exactly what it says on the tin: if the travel after a retraction would be less than 2 mm, it does not retract. You'll want that to be short, but not 0, because retraction can lead to under extrusion at the start of a new line, and every swap from one shell to the next shell right next to it is classed as travel.


1

After several email exchanges with the customer support, I was not able to find an answer. It was stated that it may have been my assembly and/or extruder mount, but I'm strongly against that after so many times reassembling. Gear backlash ended up becoming permanent. I ended up switching over to something else with a more self-sufficient design and less ...


1

Here's your problem: 1 mm retraction distance -> stringing... If you have stringing, that means that material that was supposed to end up as part of printed lines instead ended up somewhere else, leaving less material (underextrusion) where it was actually wanted. This particular test piece may not exhibit stringing, but it's likely that it ...


1

Cold/Luke-Warm pulling can cause damage and wear to the hot end, and should only be used in cases where you suspect there's a jam in the nozzle. Pulling the filament out at a few degrees above its normal printing temperature and pulling quickly is what I use, and what I've seen other's also say, and the procedure most machines use.


1

Definition: Sparse layer fill (called stuttering by the OP) Why a sparsely filled support structure... (at the support bottom) Support structures are added by Ultimaker Cura as the first part of the layer before it progresses to the rest of the print object. The bottom part of the support structure is definitely showing under extrusion, as if there was not ...


1

Having run into this type of problem at the library makerspace, under a different slicer, I had a good idea where to start the search. It is, in your case, "z-hop cura slicer" and the best return came from Polar3D. Keep in mind that this post is more than 2 years old, but if the feature was there before, it should be there now. Summary (okay, dead ...


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