burtoogle

Thanks for the project file. Yes, Cura will not add support under the bottom of those cylindrical shapes so it is not really printable at the moment. You have 2 obvious options. Either increase the infill density (maybe use another pattern) so that the cylinders do touch the infill. Or, better still, continue the cylinders down to the bottom of the part (that's what I would do).

Hi @Witawat, please save the project and then attach the .3mf file to this thread so we can look at the settings, model, etc.

See https://github.com/Ultimaker/Cura/issues/4466

Yes, this does look like a regression. Please open an issue at https://github.com/Ultimaker/Cura

OK, so there's quite a discussion going on in the Cura 3.5 thread about quality control and testing of Cura (and related firmware, etc.) and I thought I would start this new thread to make a particular point and give people a place to discuss it and related matters. Here goes... For various reasons, the products UM make evolve. The hardware is fairly static (years) but the software is a much more dynamic thing (months). The software is continually getting enhanced with new features and capabilities, old bugs getting squashed, etc. Almost always, each release brings not only goodies but new bugs and incompatibilities with existing platforms and OSes. Obviously, each new release needs a lot of testing on all 3 supported platforms (with their various versions of OS and drivers, etc.) before it can be considered trustworthy. We know that UM do a lot of testing. They could probably do more but even if they did a lot more, it wouldn't catch every bug and issue. The problem space is too big with too many variables. So this is where the community of Cura users can step up and make a real difference. Hands up those of you who use Cura with a non-UM printer and never bother to try the beta that is made available before each release. [Quite a lot of people looking a bit sheepish out there.] Why not try it? Why not give something back to UM? I'm not talking about money. All it takes is a bit of disk space and some time to install the beta and try out slicing and (ideally) printing a few of your projects. If all looks good, fine, you've done your bit. If there's a problem, create an issue on github (or post on the forum) and that's even more valuable. Yes, the software (Cura) is free for everybody to use but if you're using it on a non-UM printer then you really should be helping with the beta testing because, at the end of the day, that helps everyone, yourself included. If you don't bother to try the beta and the new release doesn't work well for you, who's problem is that? Yours! Of course, it would be nice if those people who have purchased a UM printer could try the betas also if they possibly can but I don't feel that they are in anyway as obliged as the non-UM printer owners to do so. So to sum up, the Cura user community can make a huge difference to the quality of each Cura release. Why be a freeloader when you can be a valuable member of the community?

That sound good but then it relies on one or more point releases being made. I guess if no showstoppers appear within a month or so of a new release then it could be fairly safe to upgrade anyway.

Please consider including https://github.com/Ultimaker/CuraEngine/pull/865 in 3.5.1 it would be shame not to fix that at the same time.

Hi @Link, that's a good comment and I have wondered about doing that before. It would probably be OK for printers that use z-hop but for those that don't it could leave blobs where the nozzle crossed already printed walls/skins so I think it would have to be an option rather than always behaving like that.

For example, the gyroid infill feature that should be available to all in the future probably took the best part of a working week to bring it to the point where I thought it was OK to submit for inclusion in a release. I spent a lot of time on the details because although I had something working quite soon, it was obvious that it could be better and that's what took the time. Testing and thinking. Testing and thinking. Is it perfect? Almost certainly not but I am happy enough for people to try it out.

Contributors have a huge advantage over UM employees in that the amount of time we can spend working on a new feature or improvement is only limited by our own characteristics (impatience, laziness, etc.). We are not subject to the commercial constraints of deadlines, etc. that force employees to "make do".

Sorry, I can't help, not my area of expertise. You need the support department!

Hello @SavageBelief, the easiest way to achieve what you want is to use an infill mesh placed at the bottom of your object. You can then set the infill density to, say, 80% for that region keep the rest of the model at a lower density and the resulting object will be bottom heavy (depending on shape, of course).

Hi @DHQidiTech1, it is caused by the nozzle switch retraction distance being set to 16 in your profile. If I set it to 0 then you get the following: ;Start G-code ---------------------------------------------- G28 ;Home G92 E0 G1 E3 F200 G92 E0 M83 ;relative extrusion mode G1 F1500 E-6.5 ;LAYER_COUNT:18 ;LAYER:0 G1 F1500 E6.5 T1 M107 G0 F3600 X96.903 Y65.048 Z0.3 ;TYPE:SKIRT G1 F1800 X97.404 Y64.385 E0.01563 The retraction/prime now cancel each other out. Whether this is a bug or just the normal expected behaviour I cannot say as I only have experience with single extruder printers. Hope this helps.

Hi @SkilletZA, could you please save the project file (.3mf) and attach to this thread as that contains everything in one neat package. Thanks.

Hi @zephar, thanks for the project file. I have loaded that and the layer view looks OK. I will print it on my printer (a different printer but I will use similar settings). Your machine settings are showing a filament diameter of 2.85. That is correct for your printer? If not, that's would explain what you are seeing.

Hi @Zephar, sorry, I have only just seen your reply. That file is just the model, I need the whole project which you can save using the file menu. Thanks.

Hi @Tarasque_1024, I have verified the bug. As a workaround, use the "lines" style for top/bottom rather than "zig-zag". If you do that, the problem seems to go away. I will file a bug report about this. Cheers.

OK, but unless I can see those settings and try slicing it myself, I can't really offer any assistance. EDIT - sorry, I didn't realise that was a link, I have the settings - thanks.

Hello @Tarasque_1024. If possible, please attach the project (.3mf) file that image was sliced from.

Maybe something like this ? That is a rectangular model (aka mesh) that is printed normally and another circular model that is given a mesh type of "modify settings for overlap with other models" and then it is given no walls or top/bottom layers and an infill style and density that could be what you want to shine your light through. So I am thinking that you could position a number of these modifier meshes, one for each LED. It would be a bit fiddly to set up but maybe would provide what you want.

I'm not really the best person to answer that question but I would have thought that it would be best that the model is complete and valid before it is loaded into Cura. I'm sure there's people on this forum that can advise you on this.

Update - I just noticed that setting Remove Mesh Intersection only fixes the problem for some of the skin layers and not all - you get a mixture of lines at 0, and +/-45.

Hi @TMicke, I looked at your project - it's a weird problem in that Cura thinks that the bottom few layers are bridge skin layers so it forces their line angles to a particular value. So why is Cura thinking that they are bridge skin areas? I think it is something to do with the model - notice in your images above how there is a little red region. That's actually the tip of the sword and it appears that the sword part of the model is not merged with the base and so it's kinda sticking into the base polygons and causing a problem with the bridged skin detection. I tried enablng the Remove Mesh Intersection setting and that does indeed allow the skin layers to have their correct angles. Whether it has some other bad effects I don't know. I hope this helps.

Hello @TMicke, could you please save that project file and attach the .3mf to this thread so we can look at the settings. Thanks.

Hello @zephar, could you please save a project that is showing this problem and attach the .3mf to this thread so we can look at the settings. Thanks.