Extrusion issues, where do I go from here?  

RE: Extrusion issues, where do I go from here?

Just a small update. I upgraded to the bondtech. I printed, as said, the e3dv6 holder first, went fine. Wanted to do another print, TOTALLY CLOGGED! As i checked, it was totally my fault. I screwed the heatbreak to low into the heater, so it melted where it should not melt. And after the print ended and cooled, clogged up. So this might be another thing which may also cause a clog with the original heatbreak?

Removed the clog, mounted correctly, now it workes fine. Already did PETG, PLA and now TPU. Seems good now.

Btw. i used the bondtech ptfe tube, i think that one is not really compressed in there. Dont know if this is ok. But, i guess...

Really starting to enjoy printing again  🤗 (And i have the option of going all metal in the drawer, so i am ready, just in case)

RE: Extrusion issues, where do I go from here?

@sango

Mind if I inquire what upgrades you made to the mini?  I am seeing the same issue with new rolls of PLA and PETG, fresh and opened an hour before. I see it clogging after the first layer.  I would love to get back to using this, only had the little guy for about 2 months, first month and a half of printing was amazing!  Now.. Just sad little thing sitting on the shelf. 

RE: Extrusion issues, where do I go from here?

@ndemar

Sure. I installed the bondtech heatbreak https://www.bondtech.se/en/product/bondtech-heat-break-for-prusa-mini/

Rational was: The filament got stuck either in between the ptfe tube and the heatbreak of the mini, or the heatbreak itself was somehow issues.

What you can test is to change the ptfe tube, maybe readjust the heatbreak. Check the length of the ptfe tube with the spare, the ptfe seems to "shrink" and this may cause the problem. Maybe the bondtech helps, maybe it doesnt. There are people having problems with that too.

https://help.prusa3d.com/en/guide/how-to-replace-a-hotend-ptfe-tube-mini-mini_119449

RE: Extrusion issues, where do I go from here?

@sango

Thanks for your quick response.  I'll go with the new heatbreak. As for the ptfe tube, I've adjusted and tested the original and both of the spares that came with the mini to see the same issue after a few layers.  I've tried capricorn cut to the same length and angle to have it fail the same way.  I opened the samples that came with the mini and am seeing the same problem.

I tried a very large single layer and it works fine till moving up to the 2nd layer.  I find it odd the drag across the bed keeps it flowing, only once lifting and drawing a few lines it starts to fail, first with clicking then after a minute or two, clogging. 

RE: Extrusion issues, where do I go from here?

    As I write this my Mini is printing merrily away.  I'm currently printing with some Hatchbox silver PLA that's about the same age as the white and red that gave me problems and the only issues I've had is bed adhesion, I finally washed it down with acetone and that seems to help.  I know many say no acetone on these, but washing with Dawn, and 91% IPA and even a light layer of glue haven't been fool proof.  Even after the acetone wash I only got one good print and the very next one broke loose.  When I get good adhesion my Mini prints well, otherwise it can really create spaghetti monsters.

    At any rate, I used the red Hatcbox on my I3Mk2.5s with no issue, so I have to conclude that whatever is going on the Mini just may be it's a little more finicky than the I3 when it comes to filament.  The dual gear direct drive extruder on the I3 may allow the I3 to eat filaments that a bowden drive printer may find problematic.  Of course that's speculation, but it seems pretty clear to me my nozzle was fine all along and my problem was the filament itself. 

     I'll keep my eye out for how others feel about dual gear drives and different heat breaks before I change mine, I know Prusa uses a cubic shitload of Minis for what they do and if there are improvements I expect they're produce an upgrade kit like they did with the I3.

Cheers

-Bob

RE: Extrusion issues, where do I go from here?

It really may be more about the filament...

I had some problems using a woodfill, but i had that on the other printer before. That filament is just s***. Maybe it has to be used with a 0.8 nozzle (i used a steel 0.4).

So, after some decent bondtech prints, especially with TPU. Pla was ok. But then i tried tanslucent DASFILAMENT green PLA. Started good, but then it seemed to have issues again.

So i did that what i planned before, i installed the e3d v6 (clone). That worked quite good, the green filament did a good job on a sample rocket, but had the same issues on the job it had problems before. So maybe it really just is the filament. Also that filament was a sample, and i yet have to print a spool for samples. Trying a prusament sample at this moment.

But at least it seems, that the e3dv6 clone install worked and at least did not make it worse.

Or after all those issues, disassembly and assembly, i fear that the thermistor may have gotten a little hurt in the process. Maybe i should change them in the nearer future.

FYI: the bondtech ptfe was the same length after uninstalling as on install. So at least in the short time, there was no shrinking there.

@Bob, yes, i am wondering myself, how this seems to be no issue in farms... maybe the user is at fault 😉 But regarding upgrades, i mean i have the mini+ which should be the upgraded version... We will see.

---------------

As i am writing this, i clogged again. I changed the steel nozzle to a brass one... maybe that nozzle just does not like to be here (yes i had increased the temp for the steel factor). Maybe the filament samples are just not dry enough, maybe the extruder pressure was too low/too high... i dont know. I now have the e3d nozzle in there, maybe i will order the nozzle X just to be safe.Trying a filament role, i almost never has any problems. OWL orange pla.

RE: Extrusion issues, where do I go from here?

Another Update, i realized that i (still) have the most problems when there are a lot of retractions, i lowered the retraction speed and length. Hopefully this helps further.

Reduced the retraction length to 2mm and the speed to 40mm/s

RE: Extrusion issues, where do I go from here?

Posted by: @sango

Another Update, i realized that i (still) have the most problems when there are a lot of retractions, i lowered the retraction speed and length. Hopefully this helps further.

Reduced the retraction length to 2mm and the speed to 40mm/s

So it worked for you ?

RE: Extrusion issues, where do I go from here?

After replacing the nozzle to a proper e3D I got a number of awesome prints out of my Mini.  I then opened a brand new fresh box of Prusa Azure Blue PLA and started some prints.  My first print came out well, so I started anothe print.  After about 40 minutes I heard the gear skipping.  My print completed but it was not wonderful, looking at the print I can see where it under extruded.

I can't blame the filament on this on and my PTFE is new as is my nozzle which is genuine OEM.

Frustration is climbing.

-Bob

RE: Extrusion issues, where do I go from here?

@bob-2

You should try this:

https://www.bondtech.se/en/product/bondtech-heat-break-for-prusa-mini/

RE: Extrusion issues, where do I go from here?

Posted by: @ahrimaan

@bob-2

You should try this:

https://www.bondtech.se/en/product/bondtech-heat-break-for-prusa-mini/

Yeah, I came to that conclusion.  I ordered one yesterday.  Based on the symptoms that it prints perfectly for about 40 minutes then gets worse, and worse and worse as time proceeds it must be heat creep.

-Bob

RE: Extrusion issues, where do I go from here?

Im new to 3D printing and I’ve run into some problems. When I first got the printer everything was printing fine up until four weeks after when it stopped printing halfway through a print. When I unloaded it the filament had grooves in it from where the extruder chipped away at it. After seeing that I clean the extruder I raised the heat break and also replaced the nozzle and nothing works it can’t even get a first layer down without it getting chewed up. The weird thing is I can load and unload it and also purge and everything seems fine it only happens when I print.

RE: Extrusion issues, where do I go from here?

Im new to 3D printing and I’ve run into some problems. When I first got the printer everything was printing fine up until four weeks after when it stopped printing halfway through a print. When I unloaded it the filament had grooves in it from where the extruder chipped away at it. After seeing that I clean the extruder I raised the heat break and also replaced the nozzle and nothing works it can’t even get a first layer down without it getting chewed up. The weird thing is I can load and unload it and also purge and everything seems fine it only happens when I print.