Hey there!

I’ve got a Duplicator i3 plus, on which I’m currently printing a large amount of parts for a project. Frustratingly, though, the printer has started acting very wierd the past couple of days.

After switching out filament rolls, a print that had previously printed 20 times in a row flawlessly started failing. It will lay down the first 2-3 layers perfectly, but then it will randomly stop extruding for short stretches, resulting in a complete mess.

I took the extruder apart, but didn’t find any issue. I cleared the nozzle using the technique recommended by wanhao, but it didn’t make any difference. I switched out to a new roll, but that didn’t help either.

For some reason, though, other prints worked just fine. Since I had another part which I also needed a large amount of, I started printing those in stead, while trying to find solutions.
However, after trying to print multiple parts at once using Cura’s one at a time setting (which failed), that print now fails in exactly the same way.

As this project is extremely time sensitive (I have about 200 hours of printing left to do, with only about 250 hours of available time until it has to be done), I have to get this issue resolved ASAP, or I’m completely screwed. Please help!

Do you happen to have a photo of what it looks like when failing?

If it’s a filament you’ve use before with success, the issue may be the heatsink fan starting to fail, which would cause heat creep - the molten plastic making its way higher up the hotend, which causes a clog.

The front cooling fan does not turn on until after the first layer. If the problem happened after the 2nd layer, most likely it is related to the front cooling fan(after all other testing you did). Just for the troubleshooting, you can turn the front cooling fan off by setting 0% cooling in Cura. If you can print without any problem with the cooling fan off, the cooling fan must move comparing to before.

I don’t believe it’s clogging, since it will keep printing. I’ve discovered some interesting things since I made the post.

The one on the left is how the print is supposed to turn out. While it will sometimes fail earlier, it most commonly seems to fail at this point - 2mm up. Interesting to note is that this is where the model transitions from the solid bottom, to being hollow.

I’ve got a print on now, which has failed just as the one in the picture did. out of curiosity, I let it continue, and after that point it’s printed pretty well.

Huh, I’ve always thought that the fan speed setting doesn’t carry over from cura, since flow% also doesn’t seem to apply. Either way, I’ll give it a go!