What caused this?
Right near the end of the print this happened. Is this what is known as z-wobble or something? It seemed to happen because of the speed the hot plate was moving. How can I prevent this in the future? Are there specific slic3r settings that will resolve this?
Re: What caused this?
Hi Damian,
as first guess I would think that the pool holder does not roll well, providing from time to time to much friction so that the extruder can't get filament at proper rate. Maybe can you try to move aside a bit the 2 arms of the pool holder, or trying an alternate spool holder, like the one I deisgned ( last version here http://www.thingiverse.com/thing:1454160 I'm refining it right now)
Other possibility: do you have important nozzle temperature variation during the print ?
Since it does not appear to occur during all the print, I would not think this is underextrusion.
I'm like Jon Snow, I know nothing.
Re: What caused this?
Hi,
My guess is too, that something blocked the filamentflow.
Could be a jammed roll, or a irregular or unbalanced filament.
I had this problem with an 1,75mm-filament which worked well, but at the end of the spool the diameter was temporarily at 1,9mm which caused the same effect as you described. The extruder could not push the filament, so the gaps were the result.
Greetings, Daniel
Re: What caused this?
I don't think it was the spool holder, as I was watching it finish the last few layers and it seemed fine (but I will keep a better eye on it in the future). It started happening when it had to print the tops of the last 3 crown pieces. The movement speed of the z axis while doing the infill was very quick while going from one crown piece to the other, and doing the infill.
Re: What caused this?
Hi Damian,
This definitely looks like underextrusion. You can see it down near the chin as well. Depending on the speed you were running you may need to up the hotend by 5 degrees or slow down the print speed to give the plastic more time in the melt zone.
Re: What caused this?
Hi
Another vote for filament feed issues!
Probably best to clean the nozzle as per this page: https://ultimaker.com/en/resources/149-atomic-method (from step 3) and try again.
Could also be poor quality filament.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: What caused this?
Also check how tight you've got the extruder idler, the two screws with springs on them, as a bit too tight and it can cause the filament to not go through smoothly and stick or be juddery, too loose and it will slip and not go through at all for a while. This can be affected by how clean the filament is as well.
Re: What caused this?
Thanks for the feedback everyone, I will make some changes for my next print.
The PLA I'm using is the one that came with the MK2, but I'm not sure of the quality since I have nothing to compare it to as this is my first 3D printer.
How often does the nozzle need to be cleaned on average? I only printed a couple of things since I assembled it on the weekend so would it be normal for it to get clogged this soon?
Re: What caused this?
Hi, are the extruder idler springs tight enough?
Re: What caused this?
They should be, I followed the instructions, but I'll check again when I get home from work. Would this issue be a sign that maybe they're not tight enough or too tight? 3Delight suggests they might be too tight so I was planning on loosening them a bit, is that a good idea?