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First print and... the heatsink is trashed  

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Stefan L.
(@stefan-l-2)
Active Member
First print and... the heatsink is trashed

Hello everyone...

I just finished building my i3MK3 and I printed the prusa logo, everything looked fine.

The, when I started to print my first "real" print, it all started... The first layer was not even done, and the filament got clogged. I tried the standard procedures, so cold pull, cleaning the nozzle, just to find that parts of the filament were stuck in the teflon tube. So I removed the heatsink to get the filament out, but there was no chance to get it out. So I tried to replace the teflon tube. In the video, it looked easy, but the tube wouldn't move, it even broke when I tried pulling it out. The next thing I tried (ok, desperate at that time)was to drill the tube out of the heatsink, and no, not even that was possible.

Long story short, I ordered a new heatsink now to replace it, but my question now is:

What can I do to not have this problem again? I didn't even get one regular print out of my brand new printer, everything while using the standard values given by Prusaslicer (So PLA settings, 215°/60°), using the PLA that was delivered with the printer.

Right now, I'm just frustrated, calibrating, levelling, everything went fine, just to instantly have to replace one of the main parts...

Does someone here know what I did wrong?

Posted : 26/11/2021 9:10 pm
jsw
 jsw
(@jsw)
Noble Member
RE: First print and... the heatsink is trashed

When I have a clog, if it will not clear with some gentle persuasion, I will heat up the nozzle very hot, as in 270 or so, and let it sit for a while and let the heat travel upward.

Then push the filament down slowly but firmly.  If it's broken off at the top of the tube, I'll use a dental scaler or an allen key to push.

Posted : 26/11/2021 10:13 pm
Stefan L.
(@stefan-l-2)
Active Member
Topic starter answered:
RE: First print and... the heatsink is trashed

I tried that, but it didn't work. Maybe I didn't wait long enough. Still, how can I prevent the problem from the beginning? I didn't even get past the first layer...

Posted : 26/11/2021 10:23 pm
Diem
 Diem
(@diem)
Noble Member

There are lots of threads here about first layer Z values and bed cleaning.  There is a very good chance they will mitigate your problem.

Cheerio,

Posted : 26/11/2021 11:24 pm
Stefan L.
(@stefan-l-2)
Active Member
Topic starter answered:
RE: First print and... the heatsink is trashed

So you think the nozzle was just too close to the bed? I'll have to check that as soon as the new heatsink has arrived...

Posted : 28/11/2021 2:20 pm
Dan Rogers
(@dan-rogers)
Noble Member
"What did I do wrong" - here's a guess

When a first layer calibration issue comes up, it's a head scratcher how one ends up drilling an aluminum part hoping it will make things better.  I think the place you went wrong was when you took apart your extruder to clear a clog.  You didn't describe how you determined you had a clog in the first place - but next time, maybe stop art that point (the point where you decided it would be good to take the extruder apart at all) - and either engage prusa support or come here with a question.

Maybe it was when you decided to purchase a drill.  Hard to say.

Posted : 29/11/2021 1:00 pm
Robin liked
Stefan L.
(@stefan-l-2)
Active Member
Topic starter answered:
RE: First print and... the heatsink is trashed

So I installed the new heatsink and th new heatbreak, levelling is ok, and... here we go again. the gears are grinding into the filament, nothing comes out. It does not even start to print a first layer... For me, it looks like a heatcreep, but why? Just from the beginning, the calibration pattern printed nicely, as soon, as I wanted to start printing the benchy - nothing...

Right now I'm starting to regret that I spent so much money on something that just doesn't work...

 

Posted : 03/12/2021 3:57 pm
Diem
 Diem
(@diem)
Noble Member

here we go again. the gears are grinding into the filament, nothing comes out. It does not even start to print a first layer... For me, it looks like a heatcreep, but why? Just from the beginning, the calibration pattern printed nicely, as soon, as I wanted to start printing the benchy - nothing...

OK, now we have something to work with:

You say 'the calibration pattern printed nicely' - If you reload the filament and retry, does the pattern still print nicely?

If so, please show us a picture.

You also say: 'the gears are grinding into the filament' - which filament are you printing?

You say: 'as soon, as I wanted to start printing the benchy - nothing'  - Benchys are available from several sources, which are you using?

Cheerio,

Posted : 03/12/2021 4:20 pm
Stefan L.
(@stefan-l-2)
Active Member
Topic starter answered:
RE:

The first calibration pattern (for z axis) was ok, I could not print any more patterns. I only used the filament that was delivered with the printer until now (Prusament PLA Silver [205-220° nozle, 40 - 60° Bed]), and I tried to print the benchy that was on the SD-Card that came with the printer.

On the picture you can see the part of the filament that I managed to get out with a lot of heating this time. right is upside, left is facing towards the bed. You can clearly see where the gears were grinding into the filament. The nozzle was clean, by the way

 
This post was modified 1 month ago by Stefan L.
Posted : 03/12/2021 4:31 pm
Diem
 Diem
(@diem)
Noble Member
RE:

I wonder, is your PTFE tube under the right pressure?  Is the collet engaged properly?

https://help.prusa3d.com/en/guide/how-to-replace-a-hotend-ptfe-tube-mk3s-mk3s-mk2-5s-mmu2s_21664

See step 8, second picture.

The grinding of the filament suggests your extruder idler pressure needs adjusting.

https://help.prusa3d.com/en/article/idler-screw-tension_177367

Reload the filament and retry, does the pattern still print nicely?

If so, please show us a picture.

Cheerio,

Posted : 04/12/2021 3:56 am
Stefan L.
(@stefan-l-2)
Active Member
Topic starter answered:
RE: First print and... the heatsink is trashed

I checked the PTFE tube thrice when I installed it, that should be OK. The idler screw is as loose as I can put it so it doesn't open up if you know what I mean. It still has contact and during the beginning, when I try to print, filament is coming out. Anyway, during the pattern, the extruded filament gets thinner and thinner, and in the end, it's stuck again.

Posted : 04/12/2021 4:02 pm
Diem
 Diem
(@diem)
Noble Member
RE:

OK, if you're sure.

Now tighten the idler so the screw head is flush with the housing when there is NO filament, once loaded the screw will project by about the width of the filament.  Try printing.  If you get more filament grinding, back off the pressure a little at a time.

Cheerio,

Posted : 04/12/2021 5:40 pm
Stefan L.
(@stefan-l-2)
Active Member
Topic starter answered:
RE: First print and... the heatsink is trashed

OK, so now I got this fixed, thank you everyone (especially Diem) for all the input you gave me... Long story short, I had a long session with the guys from customer service  and the result was that my PTFE tube was not all the way in, so I always got clogging between the PTFE tube and the heatsink, thus blocking the filament from going through. So it seems I managed to mess up the PTFE tube twice... Would be just great if there was an indicator somewhere that shows exactly how far it should be going in...

Posted : 08/12/2021 10:33 am
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