burtoogle

Hi @BillieRuben, I'm glad to hear the problem has been solved. I do think that frigging the acceleration and jerking the jerk (so to speak) often causes more problems than it solves. Personally, I try to avoid changing accel/jerk for different parts of the print.

Those are thin lines so they are printed as a single pass. In my example the bars in the model are 0.3mm wide and the normal line width is set to 0.5mm so the normal Cura "loopy" lines are not used and the thin line engine is used instead.

Hi @amagro, you mean like this? That's using my current Cura release. All I did was set the layer start X and Y coords such that each layer starts in the top right corner. The thin wall printing logic just goes to the nearest line when it has finished the previous line so it naturally zig-zags when the lines are laid out like this. Cheers!

Hello @BillieRuben, looking at your gcode I see that it is altering the jerk for every move. Do you still get the same problem occurring if you disable the jerk control?

Sorry, no. Those changes are not yet in the pipeline for inclusion in any Ultimaker release. I'm still working on the code and there's such a big backlog of contributions that are not being processed by the Ultimaker team that there's not much point. My releases are based on the Cura development branches so they will contain not only Ultimaker's bugs but my bugs too. I try not to post a release that is known to be broken but, as always, YMMV.

Thanks for the project. Using my Cura release I can get a reasonable result with a couple of setting changes. I changes the line width to 0.6 so that all of the wall is printed as a thin wall and changed the layer start X value to 1200 which makes the lines get started at one end rather than in the curved region. This is a great model as it shows up some remaining problems with my thin line printing so I am grateful that you have provided it. If you want to use my Cura releases you can find them at https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0

Hey @BasW, looking at your original image above that shows the really bad under-extrusion. It occurs to me that the spacing of the light/dark regions is such that it could be explained by a cyclic variation in filament diameter. You have tried printing using a different filament?

Hello @Revenant-Miami, I need the Cura project (.3mf) to really understand your problem. Please attach it to this thread.

The file that you get when you save the Cura project (file menu, Save...)

Thanks for those files @BasW, you didn't provide the project file so I can only guess at your settings from the gcode file. I see you are using a line width of 0.3mm and a layer height of 0.3mm. In my experience, it's unusual to have a line width so narrow for that layer height. Does the problem still occur when you use a wider line width? If you are using a 0.4mm nozzle, try using a line width of 0.5mm and see what happens.

Please could you attach the problematic cura projects and also the gcode that is bad. Without that it's almost impossible to determine what the problem could be. Thanks.

Hello @BasW, please save the Cura project file and attach to this thread. Thanks.

I changed the version number for the GodMode plugin and it now loads. Maybe it's not quite right because it gives the following error:

Thanks for the more useful reply. I will digest it!

Thanks for bothering to reply. Unfortunately, it hasn't left me any the wiser and it sounds like there is no documentation to refer to. I'm sure I can't be the only person who would benefit from a simple explanation of how Cura profiles/materials/machines/extruders/etc. are configured. That plugin (like most community plugins) isn't compatible with master branch or 4.0 Cura.

Hello @LFG, I cannot see anything obvious in the gcode that would badly affect the hotend temperature. What printer do you have? Do the part cooling fan(s) blow onto the hot end much? If so, perhaps they are causing the temperature to drop and, for some reason, the heater can't supply enough heat? Just guessing, really.

When walls have been replaced by travel moves because their flow is below the min wall flow setting value, they will look like any other travel move in the layer viewer (either light or dark blue depending on whether they used retraction or not). If there is only space for one wall line then the second line will have a flow of 0 and so could be completely replaced by travel moves. If all of the line segments in a wall are replaced by travel, none of those travel moves will actually be done because there would be no point as you would end up at the start location of the wall.

Although I am quite familiar with the Cura slicing engine, I know almost nothing about how Cura is configured. Does anyone have a simple explanation (wiki, blog, etc.) that describes how Cura printers, materials, variants and profiles relate? In particular, I would like to know whether material definitions are specific to particular printer types (or printer instances) or if they are shared. I see that the material print settings include items that are printer specific (i.e. retraction distance/speed) so surely you would need a new definition per printer? Another question is whether the standard profiles (Fine, Normal, Draft, etc.) are shared between printers? Thanks.

Hi @andysuth, please attach some sample gcode that shows this problem so I can check it out. Thanks.

Do you have z-hop enabled? If not, perhaps you need it?

Yes, the latest is generally the best. I keep a few old releases around just in case something gets broken. These releases are based on the Cura master branches + my own mods. So it's always possible that they have new bugs or problems that haven't been discovered yet. The releases don't get a lot of testing other than they are what I use for all my own 3d printing. I don't release stuff that is known to be broken.

That under-extrusion in the corner reminds me of a thread on the Duet forum that I started (https://forum.duet3d.com/topic/7314/trying-to-understand-pattern-sensitive-under-extrusion). I don't know if you are using a bowden extruder or not but I think maybe there is a tendency to under-extrude when a bowden extruder printer prints skin regions that have very short lines. The suggestion there was to use a feature in the Duet firmware called pressure advance that modifies the extruder rate depending on whether the nozzle is accelerating/decelerating. I think Marlin has a similar feature. I have tried to use pressure advance but, so far, not been happy with the results.

Hi @Jcarver1112, thanks for the feedback, it's always good to hear from happy users! My recent area of interest has been improving the thin wall and inter-wall gap filling capabilities of Cura. So if you have any prints that use those features, I would be grateful if you could report back if you get any bad results or if enabling those features causes a big slow down on complex prints. Any other comments/suggestions are always welcome. Cheers!

Ah, OK. That's where it has filled the gaps between walls. Yes, the standard Cura does not make a good job of that (or printing thin walls). My cura releases have a different implementation and works better in this regard (see https://www.dropbox.com/sh/s43vqzmi4d2bqe2/AAADdYdSu9iwcKa0Knqgurm4a?dl=0 for my releases). As I said, it can already be told to retract when combing travels are longer than a given distance. Would adding that complexity really make a big difference? Rather dependent on the model being sliced I think. Yes, the way that Cura is structured means that it often doesn't exploit locality as much as one would like. Outer and inner walls should often be printed together if the optimize wall print order setting is enabled. If you are losing material from oozing it means your settings are wrong (retraction length/speed, temperature, etc.) OK, thanks. Well maybe that is stronger or maybe not. Is it proven to be stronger? By highlighting only the part of the text you wish to quote!

If you are talking about infill, you can use a different infill pattern and/or change the direction of the infill lines. You an already do that when combing within infill (don't know about support). Unfortunately, because Cura can make use of multiple CPU cores it computes the print moves for each layer independently and so when computing layer N + 1 it doesn't know where layer N finished. Sorry, don't understand that, please re-phrase. Sorry, don't understand that either, can you describe some more or provide a sketch?