Assessing the condition of my printer - bed leveling, extrusion, heat block, bad filament
 
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Assessing the condition of my printer - bed leveling, extrusion, heat block, bad filament  

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stuchlej
(@stuchlej)
Active Member
Assessing the condition of my printer - bed leveling, extrusion, heat block, bad filament

Hello,

 

I have bought my mini last year, this being my first printer. Since then I have printed modest number of prints (I have not even depleted one spool), but I have been experimenting with things like different nozzle sizes etc.

My experience with the mini was flawless but progressively, things started to ... complicate. At this point, I am not able to print anything (of value) and I need to assess what is wrong with my printer to get it working again.

 

The issues manifested in following order:

  • After some time of inactivity, I have fired up the printer and tried to print a simple model. I found out, that first two layers failed to stick (to bed or to each other). I have tried to calibrate the first layer again, but it had no effect. I've started using a glue which solved the issue (for a while).
  • Meanwhile, I have started playing with different nozzle sizes. I have followed the guide posted on blog. Not having the recommended tools (nor experience) I have inflicted some scratches on the heat block. I have also caused the printer to panic several times (probably by shorting something). The nozzle sizes prints were successful, but bed leveling was an issue.
  • Meanwhile, the bed leveling issue became progressively worse and worse - to the point, that I was unable to perform the calibration properly. Some parts of the calibration run were almost scratching the surface and other completely in the air (which I was able to observe my mere eye). I was able to mitigate the issue somehow by using only a specific area of the print bed, but at this point, I am not able to print anything.
  • At the same time, I've started to hear a clicking sounds. The vibration and noise come out near the extrusion servo. At one occasion, the filament get completely stuck and when I removed it from the printer (using the FW, NOT a force), the filament was deformed - there was a groove ground in the thread. I would naively describe it as a hole left under a tire of a car stuck in a snow.

 

Since then, I have refrained from powering up the printer. I have run all the diagnostics I could find but no issues were reported.

 

What would you advise me in my situation? Clearly there are more parallel issues that need to be addressed. How do I even tell if I broke something myself, broke something by insufficient maintenance, or whether something is broken at all, etc.

Posted : 30/07/2021 10:04 am
BogdanH
(@bogdanh)
Honorable Member

Hard to say why these (various) troubles started to happen after a longer break. Anyway, the only way to find out what causes the troubles is, to inspect the printer:
1. is printer's geometry ok? (especially if you moved the printer during break period)
2. are rods and print sheet clean? (in case it was exposed during the break period)
3. is first layer calibration successful? (if not, check PINDA position or go back to 1.)
4. is filament in good condition? )maybe try another one or dry it)
etc.
Yes, it's stuff you'd do after you assembly the printer.. and even more, because maybe you left it in bad condition without even knowing at that time.

[Mini+] [MK3S+BEAR]

Posted : 30/07/2021 6:58 pm
Diem
 Diem
(@diem)
Illustrious Member

After some time of inactivity,

The printer will have been gathering dust, spiders and who knows what else...

Clean and lubricate the smooth rods, give the print bed a thorough clean; we usually suggest dish soap (Dawn/Fairy) and plenty of HOT water, dry with a fresh paper towel and handle by the edges only.

 I've started using a glue which solved the issue

Unless you are printing FLEX or polycarbonate put the glue aside.

I have started playing with different nozzle sizes.

Reinstate the default nozzle for now, until we get the machine working again.

  I have inflicted some scratches on the heat block. I have also caused the printer to panic several times (probably by shorting something)

If you get heating issues you may need to reconsider this, even then you might just have blown a fuse.

bed leveling was an issue. Meanwhile, the bed leveling issue became progressively worse and worse - to the point, that I was unable to perform the calibration properly. Some parts of the calibration run were almost scratching the surface and other completely in the air 

This is slightly worrying, can you post a picture of the result of a first layer calibration?

At the same time, I've started to hear a clicking sounds.

https://help.prusa3d.com/en/article/extruder-noises_2013

Also, if it has been lying around for a while it is likely your filament has been absorbing water from the atmosphere, look up threads here about drying filament.

Cheerio,

Posted : 30/07/2021 8:16 pm
Piasecznik
(@piasecznik)
Active Member

Do this first. Probably need large adjustment.
https://help.prusa3d.com/en/article/xz-axis-skew-correction-mini-mini_158518
Auto bed leveling cant compensate more than 1.5mm skew

Posted : 03/08/2021 9:59 pm
stuchlej
(@stuchlej)
Active Member
Topic starter answered:
RE: Assessing the condition of my printer - bed leveling, extrusion, heat block, bad filament

Hello,

I would like to thank you for your suggestions, they were helpful. I would like to summarize steps I took to resolve my issues. I would just mention, that the printer geometry seems to be OK. I have checked the belts and lubricated smooth rods tho.

The uneven first layer

I have observed an uneven first layer, similar to issues described here https://help.prusa3d.com/en/article/bed-level-correction_2267 . I have purchased and installed the new Mini+ upgrade probe. The issue disappeared after installing the probe.

Filament

My prusament is few years old at this point. I have ordered a dryer but it hasn't been delivered yet.

First layer adhesion

After being able to achieve even first layer, I have taken steps to address this issue. There were several issues.
1. Dryer compound in my drybox "melted" and corroded bearings under the spool. This may have made the filament hard to pull. I would guess, that this was the source of "clicking" noise. I have replaced the bearings. 
2. The issue (1) directly lead to issue (2). The filament scraps accumulated in the extruder driver gear. I have cleaned the driver gear.
3. I have also totally forgot about the printing sheet. Turns out, I have never treated the sheet with acetone (I only used soap previously). After applying acetone, the adhesion dramatically improved. (I only use PLA.)

 

I have still issues with adhesion on the textured sheet using PLA (since acetone is forbidden on the sheet).

 

-stuchlej

 

Posted : 20/12/2021 1:23 pm
Diem
 Diem
(@diem)
Illustrious Member

Dryer compound in my drybox "melted" and corroded bearings under the spool.

That sounds like a severe humidity problem.  Don't try anything else until you have dry filament, you may be able to rescue your existing stock - look up threads about drying.

I have never treated the sheet with acetone 

As a rough guide:  IPA between prints.  Dishwashing detergent and HOT water as soon as there is any sign of adhesion problems and acetone once or twice a year.

Cheerio,

Posted : 20/12/2021 4:31 pm
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