Bad printing - No answers from PRUSA SS  

RE: Bad printing - No answers from PRUSA SS

- Did you tried with a pristine new just unsealed PRUSA Prusament PLA and the stock material settings ?

It seems like a filament that was exposed to humidity. When I have something similar, I just throw away the filament or I put in my Electric Filament Dryer at 40° for 6/8 hours.

RE: Bad printing - No answers from PRUSA SS

Yes… we tried with multiple filaments and same issue. Yesterday i spent around 3 hrs with support running multiple tests and all looks good.
My concern is if the main pcb its damaged.

RE:

Ok,

so the next thing to check are the belts.

Looking at the tremolo pattern of the filament, it can be traced back to a problem to the belt tension. This is crucial.

I can suggest to use an iPhone if possible, because it works better with frequency detection than an Android. Recheck the tension either using the  Prusa APP and if you have another printer that works print this object: PRUSA BELT Tension Meter

Let us know.

Regards

RE: Bad printing - No answers from PRUSA SS

Thanks for your support...

X was little bit off, we adjusted and still same issue,  

RE:

Are you able to prove ACTUAL temperatures for Bed and Fliament?  I had one issue way back on a Mk3 and that was proved to be the bed temp, I had to set 80 to get 60. 

I use a Laser Temp hand gun unit.

In your case it looks to be over temp to me.

RE: Bad printing - No answers from PRUSA SS

Really strange issue 🙄 

From the initial photos it seems that Y and Y motor movement were completely out of offset. After the last tuning of the belt I see an improvement on the last photos.

May be it is not enough and can be still fine tuned. However is seems to exist also an extrusion problem, but the photo are out of focus and so it is not possible to see the layers in detail and judge the quality.

Let's back to the basic and since only few things can really create the issue, please re-check also the obvious things.

Here the causes that create the issue on the X/Y alignment of the perimeters:

• Still wrong belt tension on motor X
• Still wrong belt tension on motor Y
• Incorrect physical contact on the X,Y connector on the Buddy board (e.g. not fully inserted plugs)

Here the causes that create the issue of the irregular extrusion

• Incorrect physical contact on the Loveboard of the E motor connector
• Pressure of the filament spring on the Nextruder
• Incorrect assembly of the Nextruder
• Humid filament
• Wrong PrusaSLicer profile: Restore PrusaSlicer factory settings and re-slice the object
• Ensure the Fuzzy Skin parameter in the Perimeters PrusaSlicer section is OFF

Recheck and verify all the above things. Other improbable causes are that the Buddy or Loveboard are broken again and the power to the motors is wrong.

In such cases I would suggest to send the printer back to PRUSA to check it or if you have any 3D printing technical reseller shop around your area to check with them if they can help you with a Technical service.

RE: Bad printing - No answers from PRUSA SS

Thanks Antimix for your good recommendations, 

On Saturday i had a long conversation with Prusa Service Support.

Definitively was an extrusion problem and i swap the whole bundle of nozzle, thermistor and heater from my XL to the MK4 and works perfect...

I removed the heater from the bad assembly and we found material inside the heather hole... we cleaned and installed a new heather and same issue...  so definitively the block is not working well.

RE: Bad printing - No answers from PRUSA SS

WOW ! 😲 

But since the block is bare aluminium, just clean it as much you can and, replace the 40W Heater Cartridge and see if it works.

If not, then it is the Heatsink thermistor sensor, replace it, and then it should work. Will be interesting to discover what it was. 😉 

Keep in mind that if you swap frequently the nozzles, the failure point can be just the connector and not the thermistor or the heater itself.

Best Regards

RE: Bad printing - No answers from PRUSA SS

@fcishop I forgot to ask: I see material in the hole...

- Are you using the Legacy Nozzle Adapter ? 🤔 

The answer can open a new word.... 😉 

BR

RE: Bad printing - No answers from PRUSA SS

I clean it, replace the heather and thermistor and still failing...

Just now put a new heatblock and see what happen !!!  will keep you posted.

Saludos

RE: Bad printing - No answers from PRUSA SS

Negative...  i have the original nozzle that comes with the machine.

Interesting, right?

RE: Bad printing - No answers from PRUSA SS

There is something strange.... 🤔 

This time we replace LoveBoard, Filament, Thermistor, Nozzle and we checked the heater value that is in 100 ohm.

Still the same problem... Any recommendations?

You had already replaced the full nozzle last time and it did not solve the issue.

But now it solved the issue. 😲 

- What changed this last time ?

Can it be a bloody matter of false contact of the Nozzle connectors during assembly between the LoveBoard and Nextruder Nozzle ?

Best Regards

RE: Bad printing - No answers from PRUSA SS

Yes...  i just replace again with a new complete new Hotend and fails again...   

So frustrating.   I took a look on all the wiring and looks good.  All connectors are on the right position and well connected.

The love board i replaced looks good with no damaged components.

Im guessing the main board could has a problem?

RE: Bad printing - No answers from PRUSA SS

😲so it definitely something to do with the Nextruder Cabling. With the current Buddy mainboard it worked.

Try to just dismount the full nozzle again, removing it completely, and then reinstall it. May be this time the electrical connections will be good.

Pay extreme attention that the cable are not tighten through the slots, especially in the last connector part.

- Did you swap the nozzle many times during this printer life ?

- How do you swap the nozzle ?

Just screwing the nozzle itself with no cable disconnection, or disconnecting all the connectors, removing the full Nextruder Nozzle, swapping the nozzle, and reconnection again all the connectors ?

BR

RE:

It exists also another possibility: The Nextruder is moving slightly during the print, and dismounting the nozzle changed the Nextruder stability 😨 

Can you ensure the 3 yellow supports are tighten and well stable and the 3 green screw are tighten also ?
The nut in the centre of the 3 holders, holds the X carriage and it should also be well screwed.

BR

RE: Bad printing - No answers from PRUSA SS

- Did you swap the nozzle many times during this printer life ? Nop... just once !

- How do you swap the nozzle ?

Just screwing the nozzle itself with no cable disconnection, or disconnecting all the connectors, removing the full Nextruder Nozzle, swapping the nozzle, and reconnection again all the connectors ?

Disconnecting all the connectors,

Posted by: @antimix

😲so it definitely something to do with the Nextruder Cabling. With the current Buddy mainboard it worked.

Try to just dismount the full nozzle again, removing it completely, and then reinstall it. May be this time the electrical connections will be good.

Pay extreme attention that the cable are not tighten through the slots, especially in the last connector part.

- Did you swap the nozzle many times during this printer life ?

- How do you swap the nozzle ?

Just screwing the nozzle itself with no cable disconnection, or disconnecting all the connectors, removing the full Nextruder Nozzle, swapping the nozzle, and reconnection again all the connectors ?

BR

RE: Bad printing - No answers from PRUSA SS

All good here !!!

Posted by: @antimix

It exists also another possibility: The Nextruder is moving slightly during the print, and dismounting the nozzle changed the Nextruder stability 😨 

Can you ensure the 3 yellow supports are tighten and well stable and the 3 green screw are tighten also ?
The nut in the centre of the 3 holders, holds the X carriage and it should also be well screwed.

BR

RE: Bad printing - No answers from PRUSA SS

Hello again !!!

Finally solved...  Prusa sent me a new Hotend (nozzle, thermistor and heather) and all is working fine now.

Its interesting that used new Thermistor, block and Heather that i had for spare and did not worked.   

Thermistor and Heather has the correct resistence values and the block was new as well...

I will keep monitoring hopping not have the same problem again.

Thanks for all your support

RE: Bad printing - No answers from PRUSA SS

Hello, good for you that you solved.

However the fact that you already had used the spare part and did not work, add the possibility that is a mechanical & electrical issue. When you dismount all and reinstall (correctly 😎 ) the new parts, it works. So do not dismount again until it will stop to work 😉 

I also read that some users that get a similar issue have fixed by replacing the fuses on the power supply. It seems that some fuses may become defective and almost burn themselves with the high current, but the voltage is still transmitted, so the issue is unnoticed for the user. However they are not able to supply high current any more, and on high current peaks during prints (e.g. with motors moving and heath cartridge taking lot of power) they did not supply enough current, and the motors lost steps, and the heath cartridge can't keep the correct temperature. 😱 

Keep this in mind for future issues.

Regards