Jump to content

Extrusion problems - bad PEEK part?

Recommended Posts

Posted · Extrusion problems - bad PEEK part?

I have some strange extrusion problems since about two weeks.

Prints (same gcode) that previously have worked well suddenly give inconsistent extrusion and "easy" overhangs that usually prints well print as if it was an overhang with a too shallow angle with curls as a result.

I have tried different temperatures to no avail.

Manual extrusion feel a bit "slow" as if there some kind of plug somewhere, even at hotter temperatures.

But I have a vague memory of that my hot end started to smell a bit funny at one time and that some smoke fumes was coming out , perhaps around the same time as when the models started to come out worse (but I didn't notice initially). I think the temperature might have risen to about 250-260 degrees so I shut it off but didn't think too much of it then.

Today I started disassembling my hot end (it's been over 6 months since I needed to do it last time). I only did a little cleanup in the lower and upper part, assembled again but with same bad results.

Now I have disassemled so that the PEEK and attached brass tube is detached as can be seen in this picture:


PEEK black gunk close to brass pipe

Is this black gunk between the PEEK and brass an indication that the PEEK has melted partially?

I cannot unscrew the brass pipe from the PEEK easily and perhaps I would need to heat it up first (oven 200 degrees maybe?) but for now I've left it in my lab.


I have a friend who has spare hotend parts, perhaps I should just try to replace the PEEK/brass pipe or what do you guys think?




  • Link to post
    Share on other sites

    Posted · Extrusion problems - bad PEEK part?

    Is this black gunk between the PEEK and brass an indication that the PEEK has melted partially?


    I think it is just overcooked PLA ooze, but I'm not 100% sure. Something similar was happening to my ultimaker (and to get consistent prints, I had to keep raising the extrusion rate with each print, eventually reaching the point of stalled/ground filament).

    ...I then broke the brass tube trying to remove it from the PEEK. Even hot, it can be very challenging to remove because there is not a strong place to grab without crushing the tube. They should really make the round flange of the brass tube have two flats, so that you can grab it with a wrench without having to transfer force through the thermal break. (Actually, forget that - they should just redesign the entire hot end with less parts and fewer points of failure.)

    I ended up fixing my machine with a Makergear tube and nozzle. Prints seem to be good so far but I don't think I've solved the problem entirely yet. If I were to do it again, the first thing I would do is try a new nozzle without messing with the rest of the setup. I don't know if it was the cause of the problem, but it's a simple, easy test that allows you to eliminate one variable from the equation for the rest of your troubleshooting.


  • Link to post
    Share on other sites

    Posted · Extrusion problems - bad PEEK part?

    I agree that the black gunk is probably PLA that leaked long ago and slowly over many prints baked itself black. It is helping you by sealing any leaks. But there could be more black gunk inside which would be bad. Personally I would put the whole thing in an oven at 200C and then take a hot wire and clean it all out.


  • Link to post
    Share on other sites

    Posted · Extrusion problems - bad PEEK part?

    Thanks guys. I have new hotend parts, but no time to try them on yet. And I get my big Delta Tower printer tomorrow or Tuesday so I hope that I will take the time needed to fix my Ultimaker so I can print in parallel :p


  • Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
    • Our picks

      • S-Line Firmware 8.3.0 was released Nov. 20th on the "Latest" firmware branch.
        (Sorry, was out of office when this released)

        This update is for...
        All UltiMaker S series  
        New features
        Temperature status. During print preparation, the temperatures of the print cores and build plate will be shown on the display. This gives a better indication of the progress and remaining wait time. Save log files in paused state. It is now possible to save the printer's log files to USB if the currently active print job is paused. Previously, the Dump logs to USB option was only enabled if the printer was in idle state. Confirm print removal via Digital Factory. If the printer is connected to the Digital Factory, it is now possible to confirm the removal of a previous print job via the Digital Factory interface. This is useful in situations where the build plate is clear, but the operator forgot to select Confirm removal on the printer’s display. Visit this page for more information about this feature.
          • Like
        • 0 replies
      • Ultimaker Cura 5.6 stable released
        Cura now supports Method series printers!
        A year after the merger of Ultimaker and MakerBotQQ, we have unlocked the ability for users of our Method series printers to slice files using UltiMaker Cura. As of this release, users can find profiles for our Method and Method XL printers, as well as material profiles for ABS-R, ABS-CF, and RapidRinse. Meaning it’s now possible to use either Cura or the existing cloud-slicing software CloudPrint when printing with these printers or materials
        • 48 replies
    • Create New...