Previous filament hiding and ready to pounce
Hello all,
I've gotten to the point where I fear changing materials or colours as I have regular 'contamination' from previous filaments in my prints. I flush the old filament with the new, then do a few trials prints where all seems fine, and then at some point I see a few blobs of the previous filament appear in my prints. It's like there is a pocket in the hot-end where 'old' filament is stationary until by chance it is caught in the stream and is extruded.
I've had blues in my reds and PETG's in my PLA's (the latter is not a good chemical match I can tell you)
Did anyone else experience this or does anyone have an idea where these pockets may be? I'm suspecting the nozzle-heatblock area is the most likely but am hoping for some people with previous experience to share a few pence before disassembling and inspecting the thing.
Thank you in advance for your ideas.
Re: Previous filament hiding and ready to pounce
It is just stuck to the side of the hot end internals. It is less noticeable when going from light to dark colors but darker pigments take very little residue to stain replacement filament. Not much that can be done besides doing more purging than you have been.
Re: Previous filament hiding and ready to pounce
Too bad but understandable. Thank you for your reply, you probably saved me an afternoon of fiddling with the hotend.
Re: Previous filament hiding and ready to pounce
Have you checked out cleaning filaments they say it sticks to particles and works efficiently that doesn't use a lot? Here's a vid of Ron Hunt really good info this might help .
Re: Previous filament hiding and ready to pounce
I use this whenever I swap to a lower temperature material. You only use a couple/few inches per cleaning, so it lasts a very long time. If I am going from PETG to PLA, I preheat to PETG temp and extrude some of this through, then preheat down to PLA temp and load in my PLA. Works great. It extrudes at a wide range of temps, so it's great to use as a transition material.
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