Began using non-Prusament filaments and now I have all sorts of problems - Arrggghhh!
 

Began using non-Prusament filaments and now I have all sorts of problems - Arrggghhh!  

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navillus5
(@navillus5)
Active Member

Hi -

I recieved my Prusa Mini in March 2020 - it sits on a countertop right next to my MK3s. The little guy has been a champ and has never, ever given me the slightest problem. I have printed using both Prusament PLA and Prusament PETG and the resulting parts have always printed flawlessly. You might have noticed that I mentioned that I have only been using PRUSAMENT up until a week ago. 

With the rise in the price of Prusament, I decided to branch out and purchased a couple of spools of PLA from MatterHacker and my excellent, reliable, flawless printer became a nightmare. Everytime I would try to run a 1st layer calibration, the process would start with the nozzle purge but the extrusion would stop before it reached the end of the calibration pattern. After multiple load and unload cycles, multiple cold pulls, dissassembly and complete cleaning of the filament feed system, adjustment of the tensioning screw - I finally through my hands up in frustration and gave up. 

I then ordered a spool of Hatchbox PLA and I managed to get the MINI to print a couple of parts but then the whole problem started over again. The next step is to disassemble and reassemble the heaterblock/heatbreak but I have misplaced my 1.5mm Allen key and need to order a new one before I can do that step.

So... can anyone weigh in on the reason why all of these problems started after I stopped using Prusament? Is there a fix? Am I crazy? Is my MINI just a loyal machine and simply refuses to work with any other filament?

 

Posted : 21/02/2021 11:05 pm
fuchsr
(@fuchsr)
Reputable Member

Did you try to adjust the screw at the extruder? When I received my first Mini, I had issues with some filaments that were solved by properly adjusting the tension screw at the extruder. 

Posted : 22/02/2021 2:39 pm
cwbullet
(@cwbullet)
Illustrious Member

@fuchsr

I will second this.  I have always found that between adjusting my Z and the tension on the idler screw are the most common errors.  

This post was modified 2 weeks ago by cwbullet
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Chuck H
3D Printer Review Blog...
Posted : 22/02/2021 6:20 pm
navillus5
(@navillus5)
Active Member

Yes. I also adjusted the tensioning screw. When I did this I backed the screw all the way off and slowly increased it until the filament began to move into the extruder. When this didn't work I did play around with increasing the tension but nothing really seemed to have worked. 

But even if this was the case it doesn't address the reason why this problem would have shown up when I switched from proceedment to a generic PLA. 

Posted : 22/02/2021 8:13 pm
fuchsr
(@fuchsr)
Reputable Member

Because maybe nominally these are all 1.75 mm filaments but not all are created equal. It’s not only that the diameter tolerances may vary but also — for lack of better word — the “texture” of the filament. Some are “grippier” than others.

But then again, you seem to have checked the idler screw out, at which point I’m out of ideas.

Posted : 22/02/2021 8:16 pm
fuchsr
(@fuchsr)
Reputable Member

Well, one more idea. If you still have Prusament, does it still work — at which point you can probably exclude issues with the hotend — or is it also acting up now?

Posted : 22/02/2021 8:18 pm
cwbullet
(@cwbullet)
Illustrious Member

@fuchsr

I concur.  Some have more variability in diameter so they do not print as well and jam more.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 22/02/2021 8:30 pm
navillus5
(@navillus5)
Active Member

Thanks for the replies...

I usually had the MINI setup to print PETG and my MK3S to print PLA. This problem began when I came to the end of my last spool of Prusament PETG (I still have a couple of meters left, so I can do some limited comparision tests).

When the problems began, I did a sanity check and switched back to the PETG and the MINI worked flawlessly. Then as I related in my original posts, I gave up on the MatterHacker PLA and switched to Hatchbox PLA - same issue with both. It was at this point that I started "messing" with the printer. I really didn't want to do that route - because it had been printing fine, so its not like something suddenly went wrong with the printer. 

Anyway - I am now waiting on a 1.5 mm ball driver so that I can disassemble/reassemble the nozzle/heating block/heat break.

BUT - The primary issue remains - WHY did this happen and is this just my machine or has anyone else experienced this type of problem?

As an FYI - My MKs3 has been printing fine with all three of these filaments. So that puts me along the path of thinking is there some sort of inherent design flaw in the MINI feed/extruder system?

I have found it notable that BondTech has created a dual-drive extruder that they are marketing as an upgrade to the MINI.
https://www.bondtech.se/en/product/prusa-mini/

If things don't improve when I rebuild the MINI hot end, I might make the investment. But I am also wondering if Prusa will be offering an upgrade kit in the near future - hopefully at a reduced cost for us early adopters...

Posted : 23/02/2021 2:41 am
fuchsr
(@fuchsr)
Reputable Member

Haven’t really heard anything negative about the Bondtech extruder. I have the Trianglelabs clone of it, which works fine, but then again I didn’t really have issues with the stock extruder either. Easy install. Just remember to set the esteps in the startup Gcode. 

Posted : 23/02/2021 4:42 am
cwbullet
(@cwbullet)
Illustrious Member

@fuchsr

I do not own one, btu there plenty of folsk singing praises here, Discord, and Reddit.  

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Chuck H
3D Printer Review Blog...
Posted : 23/02/2021 10:31 am
navillus5
(@navillus5)
Active Member

@fuchsr

Thanks again for your response, but I would really like to know if you have an opinion as to whether this is an issue related to my particular machine or is this a design flaw in the MINI extruder?

Posted : 23/02/2021 12:43 pm
fuchsr
(@fuchsr)
Reputable Member

Could the extruder be better? Sure.  Are there reports of issues with the extruder? Sure. Is it flawed? I doubt it. Forums like this have an obvious selection bias for folks with issues with their machine. You just don’t hear much from people whose machines run just fine. I believe Chuck, who had chimed in here, has four minis and as far as I can tell no issues.

Now for your particular machine, you’ve tried so much, there sure could be something physically wrong. I’d get on the chat with Prusa support (better than email) and see what else they suggest. 

just another idea, and maybe you’ve tried it. I’d clean all the Bowden tubes and check them for damage. Including the two small pieces inside the extruder and the hot end. 

Posted : 23/02/2021 1:35 pm
Peter M
(@peter-m)
Prominent Member

If all fails. I do this.

Clean bed with dish soap.

Move extruder higher, and extrude and look if filament is coming out in a straight line and thick enough.

Then print a few square on the bed, adjust the first layer calibration, and start to high, and lower to see what works best.

 

 

Posted : 23/02/2021 9:30 pm
cwbullet
(@cwbullet)
Illustrious Member
Posted by: @peter-m-3

If all fails. I do this.

Clean bed with dish soap.

Move extruder higher, and extrude and look if filament is coming out in a straight line and thick enough.

Then print a few square on the bed, adjust the first layer calibration, and start to high, and lower to see what works best.

 

 

This is a repetitive theme on this forum.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 23/02/2021 11:19 pm
navillus5
(@navillus5)
Active Member

So I've solved the issue.

I followed this set of steps and instead of replacing anything I just used my existing hardware. 

https://help.prusa3d.com/en/guide/how-to-replace-a-heaterblock-heatbreak-mini-mini_122769

I'm not sure if it made much of a difference but I'll also note that I used a Dremel and a wire brush attachment to clean off both the heater block and I use the brass brush to clean off the threads of both the nozzle and the heat break. 

I also think one of the key steps is to make sure that the boden tube is pushed all the way up That's when they talk about maintaining the compression during the assembly. 

So it's still a mystery as to why this happens at the exact point that I switched from the procurement PETG to the generic PLA filaments. But my suspicion is that it's more related to the difference in materials than the difference in the filament manufacturer. 

Posted : 25/02/2021 9:39 pm
fuchsr
(@fuchsr)
Reputable Member

@navillus5

Ha, I knew it — Bowden tube!

Posted : 25/02/2021 11:16 pm
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