Reclaiming a tungsten nozzle?
I'm wondering if anyone else has had this issue.
About a year and a half ago I switched to a tungsten nozzle on the MK3s (ca. US $50). It's been performing fine until very recently.
A model I was printing had a vertical shaft with lots of artifact, so I did an inspection of the works and found the filament to be coming out at an angle when manually advanced. This has happened before a couple of times, but it was always easy to fix.
I did a 'cold pull' with cleaning filament and probed the hot nozzle with an acupuncture needle with no effect.
I then got out one of the .4mm cleaning bits and mounted it in a pin vise, got the nozzle good and hot, and attempted to clean out any obstruction that way, something that I have done a few times over the years.
Unfortunately, the cleaning bit broke right at the nozzle opening as I was twisting.
There is not nearly enough of the bit sticking out to grab and pull. I heated it to 280C or so and tried to push the remains of the bit upward with both the broken stub of the bit and a needle. It will not budge.
I then pulled the nozzle out, put it on the bench, clamped it to the tip of a soldering iron, got it very hot and again tried to force it one way or the other, no go.
I installed a regular brass nozzle to get the machine back up again (works fine) but I would sure like to get the tungsten one working again.
Has anyone had a similar situation? If so, how did you clear it.
Thanks.
RE: Reclaiming a tungsten nozzle?
Instead of heating it, you could try freezing it and then trying to tap it out. If your 'cleaning bit' has a higher expansion coefficient than tungsten then heating it will actually make it tighter.
RE: Reclaiming a tungsten nozzle?
Let me try that, and that might explain why the bit bound and snapped, as the nozzle was hot when I did it. Thanks.
RE: Reclaiming a tungsten nozzle?
I'm going to second what @neophyl said and add that once you get the whole thing cold you could try heating the nozzle with a soldering iron, if the bit says cold and the nozzle warms that could open more space to get the bit out.
Cheers
-Bob
Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit