I've been chasing a bit of an issue, and not really sure what's going on.
I'm doing rather large items (say a 5" cylinder which is around 2" tall and about 25% full of plastic!), so it's generally a 8-10hr run. I'm running VERY SLOW (15-20mm/s) speeds to get accuracy and cut down on layer/gap issues..
Running PLA, my print will run into say 70-75% completion, and will begin to falter - sometimes the head just completely clogs up. Sometimes I'll have TONS of silk all over the print.
I've had the guess that this is being caused by a heat build-up over time on the head.... So I've been experimenting more with the layer fan and use of it to help maintain temp over time.
My Orion came with a little squirrel cage, mounted on the side of the head, but with no shroud - it just blows in the general direction of the tip.
So the outcome of this is that if I run that fan at 100%, it will actually cool off the hotend too much - at 100% it'll knock 20 C off the hotend tip, and actually cause failure..
at 75% speed it is a healthy balance - the tip keeps pretty consistent temps.
So what should I be doing to counteract the unit clogging up 5 or 6 hrs into a build??
I've been thinking about printing a different layer fan shroud that's more accurate, so I can keep temps more steady..But I"m not realy convinced that this is the issue.
thoughts??
