Kathryn

I'd like to download the Solidworks Cura Plugin, but seem to be unable to get any plugin's download to start. Once I hit "Install", it just sits there without showing any sort of progress for hours at a time. The internet connectivity is good and I'm able to connect to my Ultimaker just fine, so I'm assuming connectivity isn't the main issue. Is this more likely to be a bug or just an issue with download permissions? For instance when downloading Cura originally I needed admin permissions, but there is no popup giving me that indication now. If it's helpful I'm currently running Cura 3.3.1, although I had a similar issue with Cura 3.2.1.

I recently purchased a ruby-tipped nozzle from 3dSolex to help print chopped carbon fiber filament. So far the new extruder and nozzle have worked extremely well and have made some beautiful prints. Today though, I noticed it was under extruding on some smaller pieces I was printed, so I decided to do a printhead cleaning to clear out the blockage. The hot pull went fine, but the cold pull is where I ran into issues. Essentially when I went to pull the cold filament out, it did NOT want to come out. I've done cold pulls before with little to no trouble, but this time the filament was so stuck in the extruder that it was literally pulling the nozzle up when I yanked on it. I ended up getting a coworker to come help and instead of finally freeing the filament it instead snapped somewhere inside the extruder. I figured this wouldn't be a big deal just because you can reheat the nozzle and start pushing the filament out again. No such luck. I've tried setting up for another hot pull and also manually changing the temperature of the nozzle to 220C with no extrusion taking place. My fear now is that whatever was initially blocking the filament has moved to keep the broken piece from being able to exit the nozzle, leaving the small chunk of PLA stuck inside. That said, any advice on how to free the blockage from the inside of the nozzle? My best guess as of right now is increasing the temperature and maintaining a more constant pressure, but other than that I can't think of many other options. Edit: Fixed issue Ended up having to disassemble the printcore to reach the set tube the filament was stuck in and then heated it up with a heat gun. Ideally there is an easier solution out there, but for the time being it seems to be flowing again.

That sound like good advice as well. I have noticed that it's fairly common for the filament to start curling up when it first comes out of the nozzle so I've been doing my best to keep the nozzle itself clean using tweezers, which tends to help a bit. I'll look into doing more hot pulls though- those are typically pretty fast so it'd be less of an undertaking to have to do that before every print.

Yes, the filament is always sitting in a drybox even when it is feeding into the printer. I've also observed that crackling of bad filament during the initial purge, and it is true that that usually clears most of the crud out of the way before the print starts. It's interesting to hear that you haven't had to do a hot/cold pull in a month or two- it may be that in that case scheduled maintenance of the print cores may take care of the problem effectively and that the earlier problems we experienced were entirely due to saturated filament.

Yeah that does seem to be the most effective solution- I was hoping to avoid having to do a hot/cold pull every time I start using the PVA again, but it's such a finicky material that may just be what it takes. Good news is we do already have a small dry box that the filament sits in during printing, and it is true that that has helped substantially with avoiding clogs in the middle of a print.

That is certainly a possible approach - the problem is that this Ultimaker is being set up to be used in production, which means it would be expected to make trays of parts at a time to reduce change-over/excess handling. If it were just for engineering though I agree, printing one at a time would work fine.

I have an Ultimaker 3 printer that for the most part performs extremely well with little need for hovering/constant supervision. However, there are times where a print will be started, the prime blob and first layer will print successfully, and then I'll come back 20 minutes later to find that the filament has stopped extruding. This most commonly happens with PVA, and from what I can tell from my subsequent hot/cold pulls it is because the nozzle did have a blockage in it, but for some reason the print initially started just fine. That said, is there any way to see if a nozzle is clear or blocked before starting a print job? Or are there any good tips on avoiding blockages entirely? One strategy I've been using recently is backing the filament out of the nozzle when it is not in use, which so far has helped somewhat. That said I also run longer print jobs with PVA support where the nozzle may be sitting idle for a period of time once the primary material no longer needs support to finish the print, which means there's a higher risk of blockages for the next print job.

I've recently started printing a set of stoppers out of Ultimaker's TPU95 material. This material is great and extremely shock absorbent, but it tends to string more than other filaments due to its flexibility. This becomes a slight issue when printing two of these stoppers in the same build tray, since when it goes from one tower to another it will string and leave a small blob of material on the surface of the part. In other materials these blots can be easily taken off, but with TPU it becomes harder since the material tends to elastically stick together. Has anyone found any particularly good retraction settings to reduce stringing in TPU? Here's a picture to illustrate the blotting I'm talking about, seen on the front surface of the square tower:

Thanks for the in-depth response! We'll certainly be considering some of these methods going forwards. The initial horizontal expansion setting is not one I had noticed before, so that on it's own is a great find.

Thanks for the feedback! Since the z dimension isn't actually that crucial I will probably just go back to using the .15 layer height I've been testing with. @gr5 it's interesting that you mention the horizontal holes shouldn't require adjustment, since I've actually had to tweak both vertical and horizontal holes by anywhere from .01 to .02in at a time, at least for this part in particular. In your experience do these issues become more pronounced as you scale up? You also mention this is a particular issue with PLA- are other materials like Nylon better suited to dimensional accuracy? As for the warping it is possible that that may be due to me tweaking some of the first layer settings to help reduce the elephants foot on the part- I have been using the glue stick + wet paper towel method but I'll be sure to check out your other suggestions as well. Thanks!

Recently I've begun test printing a part for production on my UM3 that has a number of dimension-sensitive holes in the X and Z directions. As a test I went ahead and printed the part with both Normal (.15) and Extra Fine (.06) settings using Ultimaker PLA with PVA supports. The Normal print turned out fairly well, but the Extra Fine part ended up with some rather severe pillowing on the top layer, as well as significant warping in the back right corner despite using a thin layer of glue as directed. I used the default settings for the Extra Fine, so there should have been 17 top layers which should have reduced the pillowing somewhat, but clearly it didn't do much. What's also odd is that the finish of the Extra Fine print is actually much more matte than the Normal part. Does anyone have experience printing larger surface areas with the Extra Fine setting that might reduce this pillowing? Also are there any methods other than a glue stick that are useful for reducing warping? For the time being there isn't an enclosure we can use for the full printer, but if that is a common solution it'd be good to know. Any other general tips and tricks for getting a part to print with consistent dimensional accuracy would be welcome, since as of now I've had to go into the files for every part I've printed to make adjustments for the printer.