Kazoo (tall and narrow)
In the past couple of weeks, I built a MK3S+ with an MMU2S. I have a nearby Microcenter, so picked up some Inland PLA+ in a variety of colors. After some experimentation, I learned I needed to print a bit cooler with this filament, otherwise the nozzle would leak significantly. I landed at an extruder temp of 210°C, both first layer and other. Even at the lower temp, I'm still getting some threads across the gaps when the extruder makes a jump:
I haven't yet tried modifying retraction settings. This bit of threading is tolerable, and I've just peeled it off at the end of each print, though I wish I could resolve it altogether.
But then I tried to print this Kazoo, which has now failed 4 or 5 times:
https://www.printables.com/model/65397-kazoo
In one of my attempts, I had the same outcome as this print (which I pulled from the comment on the model page, since I didn't get a photo of mine):
I tried with a 7mm inner-outer brim, and my next print looked ended up like this:
I wasn't there when it went wrong, so I don't know which happened first: the adhesion failed, and the model got in the way of the extruder, or the model got in the way of the extruder, and it pulled it off the sheet. Same post as the above suggested a support for the threaded part, which seems reasonable, but almost every other comment noted this was an easy print. Is the Inland PLA just a poor choice?
For the moment, I'm using the Prusa stock buffer and spool holders for the MMU2S, laid out widely across two desks, and the filament seems to be moving well through the whole path (though, just once, the spool rolled off the holder).
Am I missing something? Help. 🙂
Thanks in advance!
Best Answer by Neophyl:
The ‘stringing’ on your first pic with the circles isn’t what we would class as such. It’s not extra leaking from the nozzle during movement. That’s not adhered filament that’s been pulled across as it moves to the next position. That’s caused by either too steep of an overhang for your layer height (which would be displayed as dark blue on the print preview in the slicer generally) so that there’s not enough on the layer below for the layer to attach to, or weak inter layer adhesion which is what you get with printing at too low a temperature.
Threaded parts you normally use a lower layer height to counteract the pitch of the thread causing overhangs. Given that your brim lines are separating too on the part that being knocked over I’d also think that your first layer isn’t squished enough, that would also contribute to poor first layer/part adhesion.
So 2 things. Post the results of a single layer calibration print to advise on your live z adjustment. There are loads of posts on the forum pointing out what you should be aiming for.
Secondly post a zipped up copy of your project file (3mf produced by file>save project as ) to here so people can take a look at the preview of the slice and settings and give feedback on them.
RE: Kazoo (tall and narrow)
The ‘stringing’ on your first pic with the circles isn’t what we would class as such. It’s not extra leaking from the nozzle during movement. That’s not adhered filament that’s been pulled across as it moves to the next position. That’s caused by either too steep of an overhang for your layer height (which would be displayed as dark blue on the print preview in the slicer generally) so that there’s not enough on the layer below for the layer to attach to, or weak inter layer adhesion which is what you get with printing at too low a temperature.
Threaded parts you normally use a lower layer height to counteract the pitch of the thread causing overhangs. Given that your brim lines are separating too on the part that being knocked over I’d also think that your first layer isn’t squished enough, that would also contribute to poor first layer/part adhesion.
So 2 things. Post the results of a single layer calibration print to advise on your live z adjustment. There are loads of posts on the forum pointing out what you should be aiming for.
Secondly post a zipped up copy of your project file (3mf produced by file>save project as ) to here so people can take a look at the preview of the slice and settings and give feedback on them.
RE: Kazoo (tall and narrow)
Thank you so much for your quick and thorough reply! Your advice was spot on: as soon as we redid our first layer calibration, everything just fell into place. I went back to the hotter print temps, and am getting better prints all around. Thanks again!