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Random Discolored Blobs in Prints  

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d.v
 d.v
(@d-v)
Active Member
Random Discolored Blobs in Prints

Hello,

I recently dis- and reassembled my hotend because of a jam, ultimately replacing the PTFE tube. After trying a few different prints, I have noticed that all of them end up with a number of discolored blobs, strings, and lumps.

The gray filament has brown blobs and the white filament has gray blobs and strings (they're not from the gray filament).

Before replacing the tube, I printed at 217C with no issues. The gray model was also printed at 217C, but the white one was printed at 210C. It seems that the temperature has not affected the blobs.

Posted : 16/09/2017 10:16 pm
JeffJordan
(@jeffjordan)
Moderator
Re: Random Discolored Blobs in Prints

seems that your nozzle/hotend is leaking after the disassembly of your hotend.
did you follow the proper instructions about assembling the hotend ?
you need to heat it up at max. temperature while assembling heatbreak & nozzle, to get it "watertight".

there are several postings here about a leaking nozzle... where all the required "how to" links (mainly to youtube tutorials) are linked.
if you are able to use the search function of this board, you should find such threads like this one, this one or that one .... but there are still more.

---

by the way: from your pictures (especially the one with the silver filament) I can see that your first layer setup is not good. you'll end up in upcurling prints or prints that get loose during the printing process.
have a look at this thread as well.

ps. I really like these squeezy turtles :mrgreen:
already printed a zoo of them.

dem inscheniör is' nix zu schwör......
Posted : 16/09/2017 10:34 pm
d.v
 d.v
(@d-v)
Active Member
Topic starter answered:
Re: Random Discolored Blobs in Prints

seems that your nozzle/hotend is leaking after the disassembly of your hotend.
did you follow the proper instructions about assembling the hotend ?
you need to heat it up at max. temperature while assembling heatbreak & nozzle, to get it "watertight".

I did follow the official instructions for replacing the PTFE tube, but now that you mention it, I'm not sure if I heated up the extruder before screwing the nozzle back in. I'll give it a try and let you know how it goes. Thanks!

I'm glad you noticed the turtle, too 😛

Posted : 17/09/2017 1:05 am
d.v
 d.v
(@d-v)
Active Member
Topic starter answered:
Re: Random Discolored Blobs in Prints

Alright. After a lot of waiting, I got a whole new extruder (like you said, it was leaking and melted filament was everywhere) and assembled it. This time, I tightened the nozzle while the printer was heated. I then ran the default v6 calibration and your version as well. Both printed nicely with no leakage.

However, I noticed there is a gap between the nozzle and the heater block. Is this normal, or do I need to tighten it more?

Posted : 15/10/2017 12:08 am
PJR
 PJR
(@pjr)
Moderator
Re: Random Discolored Blobs in Prints

https://wiki.e3d-online.com/wiki/E3D-v6_Assembly

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 15/10/2017 10:17 am
d.v
 d.v
(@d-v)
Active Member
Topic starter answered:
Re: Random Discolored Blobs in Prints

Hi Peter,

I did follow those instructions when assembling the hotend. I have been printing for a few days now without leakage, although there is still a visible gap between the nozzle and heat block. After reading the directions again, I realized that the goal was to get a seal between the nozzle and heatBREAK, so thank you.

Glad to be up and running again!

Posted : 21/10/2017 7:05 pm
PJR
 PJR
(@pjr)
Moderator
Re: Random Discolored Blobs in Prints

Yeah, the ides is to get the gap as small as possible, but still have that gap.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 21/10/2017 10:19 pm
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