Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion
 
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Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion  

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Halle.s
(@halle-s)
Trusted Member
Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion

I'm having an issue that started happening overnight.


First I completely re-calibrated the printer including tuning the PID. I did another print and the weird waves as seen on the pictures kept happening.

I thought the extruder was clogged so I unscrewed the extruder gear panel, pushed a good amount of filament through manually and then did a cold pull. Nothing was out of the ordinary. I did another print which is the one presented in the pictures in this post. The print failed. It got unstuck from the bed. That's not an issue, it just needs a good cleanup. But that's when I noticed the whitish plastic bits where the nozzle got stuck in the print. Then I took the brass brush I use to clean the nozzle and gave it a good brush. It started raining white bits of plastic.

This blue PLA is all I've printed with in months. I'm about halfway into this roll and I haven't switched to anything white.

The melting point of PTFE is 300+°C so I know that it can't just melt, but what else could it be? It doesn't seem to mix up with PLA too well. Can PLA lose its color when subjected to a high temperature for an extended period of time?




Posted : 30/10/2018 11:19 am
Mustrum Ridcully
(@mustrum-ridcully-2)
Honorable Member
Re: Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion

if the lock on the top of the hotted radiator is not locked the ptfe tube inside can be pulled up during retracts and unloads till it touches the bond tech gears and bits of it can be ground off.
I think it is good practice to install a collet lock c clip as sold by e3d but dozens of versions of it can be found on sites like thing verse to be printed at home
https://e3d-online.com/collet-clips

Posted : 30/10/2018 2:40 pm
Halle.s
(@halle-s)
Trusted Member
Topic starter answered:
Re: Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion

Thank you but I fail to see where in the printer that would fit. Also the top of the PTFE tube looks fine on inspection.

Posted : 30/10/2018 4:42 pm
Mustrum Ridcully
(@mustrum-ridcully-2)
Honorable Member
Re: Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion

The black thin is the collett lock when it in the down position the tube is free to move up and down when it is up it is locked the clip fits to keep it in the up position and it takes no space the blue one is for our size of hotend.
that said if you see no grinding on either of your PTFE tubes then the plastic is not coming form them

Posted : 30/10/2018 9:39 pm
Halle.s
(@halle-s)
Trusted Member
Topic starter answered:
Re: Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion

Does anyone else know what my issue here could be?

Posted : 02/11/2018 7:30 pm
Halle.s
(@halle-s)
Trusted Member
Topic starter answered:
Re: Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion


The black thin is the collett lock when it in the down position the tube is free to move up and down when it is up it is locked the clip fits to keep it in the up position and it takes no space the blue one is for our size of hotend.
that said if you see no grinding on either of your PTFE tubes then the plastic is not coming form them

I finally got around to dismantling my extruder and it turns out you were right. The white plastic was actually the result of the blue PLA getting cooked. For some reason it turns white. So the white plastic was sort of a red herring, but securing the collar with a nylon washer fixed the issue.

Posted : 02/04/2019 5:22 pm
Mustrum Ridcully
(@mustrum-ridcully-2)
Honorable Member
Re: Is this my PTFE tube dying? Whitish plastic in my print and inconsistent extrusion

It is a very sneaky fault as it can take many hours of operation(with the printer working perfectly) with at a guess thousands of tiny retract commands on the filament for the lack of the lock to result in this problem. Glad it is fixed for you.

Posted : 02/04/2019 7:51 pm
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