poor print quality  

Re: poor print quality

I may have discovered something that may explain both the squeaking X belt and the vertical lines. I thought I had fixed my squeaky X belt by moving it back a bit. But it is still noisy. I looked at the offset along the rod and it should be centered but it drifts to one side as it gets closer to the X end. So my theory is the pulley axis is not aligned causing it to pull to one side. This causes rubbing and squeaks, but also can catch the edge of the belt teeth, creating a spatial harmonic. I measured the vertical lines on a print and it looks plausible, but possibly coincidence.

I had the same ringing on my old K8200 and found the cause to be the belt running on the smooth pulley - replacing the pulley with one with GT2 teeth removed the ringing. If the ringing marks has the same distance as the teeth on the belt this could be the cause.

So the seemingly noisy Y axis bearing got the better of me. I decided to swap them out with some Igus I got. I was a bit concerned about the plastic housing but figured what the heck. When I pulled my bearings I confirmed they were indeed set up with bearings at the top. For a test I rotated them 45 degrees out of curiosity; I couldn't tell a difference in drag or sound.

I installed the Igus VERY carefully using the "just touching the surface" + a slight bit more. Prior to the final bit I ran them back and forth to help "seat" which actually seemed to help a tiny bit. After its all done the bed is VERY quiet and only hear motor noise.. will have to see how they hold up.

While removing things I found a LOT of black crap on either end of the rod with 2 bearings.. was almost like a bearing was breaking down. Could have been my issue, but couldn't determine which one was the culprit.

I'll yell if the printer blows up or something 🙂

Ron

Igus are good bearings, very quit, but I had to replace them on my MK2S after half a year as they had worn and gave too much backlash. That was on the hardened improved steel rods that came with the MK2S kit.

Re: poor print quality

The problem is that I was getting also more quality with MK2S. Rigid frame and missed steps detection should help a bit with quality also...

Yeah same here, I dont expect better prints from the MK3 but I do expect it to perform just as well. Printing the same file at 30mms on both printers and the MK3 still has ringing and ghosting so its either a firmware issue or something wrong with the hardware. I've narrowed it down to my X axis and am awaiting new rods and bearings from Prusa, fingers crossed it solves my issues

Keep us updated......

On those files... did you use the same acceleration and jerk settings?

Will do. Yeah I changed the jerk and acceleration to match the MK2 and still had ringing however what Jltx said about the belt could possible be the issue too. When I tightened the belts the piles started squeaking and rubbing

Re: poor print quality

Moved post to:

https://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/replacement-bearings-recommendation-t2085.html#p57445

Re: poor print quality

Yeah same here, I dont expect better prints from the MK3 but I do expect it to perform just as well. Printing the same file at 30mms on both printers and the MK3 still has ringing and ghosting so its either a firmware issue or something wrong with the hardware. I've narrowed it down to my X axis and am awaiting new rods and bearings from Prusa, fingers crossed it solves my issues

Keep us updated......

On those files... did you use the same acceleration and jerk settings?

Will do. Yeah I changed the jerk and acceleration to match the MK2 and still had ringing however what Jltx said about the belt could possible be the issue too. When I tightened the belts the piles started squeaking and rubbing

How did you change those values in the MK3 on the firmware?

Did you use Pronterface?

Re: poor print quality

Keep us updated......

On those files... did you use the same acceleration and jerk settings?

Will do. Yeah I changed the jerk and acceleration to match the MK2 and still had ringing however what Jltx said about the belt could possible be the issue too. When I tightened the belts the piles started squeaking and rubbing

How did you change those values in the MK3 on the firmware?

Did you use Pronterface?

In terminal on Octopi I entered M205 X10 Y10 but pronterface would work just use M503 afterwards and you should see the new Jerk settings. You could add it to your start gcode. The current settings for the MK3 are both 15 but 10 on the MK2 however I didnt see much difference in quality sadly

Re: poor print quality

Thank you Jason.

Well... just to test it out i decided to change the Y-Axis bearings... I swapped them for the IGUS RJ4JP-01-08... These bearings have a minor side play in the smooth rod... The regular LM8UU also have it but it seems to be less noticeable. Previously i had a Skew of 0.10º, now i have 0.13º. Not that much of a difference and i'm not sure if its the IGUS bearings fault.

So, anyway... i decided to make two prints with the "old" settings where i got ringing problems.

This is with the regular LM8UU bearings:

And this is with the IGUS bearings:

Quite a difference, could the regular bearings be biding the Y-Axis movement somehow causing vibrations and subsequently that ringing? Anyway its still not perfect.

Do you guys think i should change the X-Axis bearings to IGUS bearings too? I have more of them here!

Re: poor print quality

Thank you Jason.

Well... just to test it out i decided to change the Y-Axis bearings... I swapped them for the IGUS RJ4JP-01-08... These bearings have a minor side play in the smooth rod... The regular LM8UU also have it but it seems to be less noticeable. Previously i had a Skew of 0.10º, now i have 0.13º. Not that much of a difference and i'm not sure if its the IGUS bearings fault.

So, anyway... i decided to make two prints with the "old" settings where i got ringing problems.

This is with the regular LM8UU bearings:

And this is with the IGUS bearings:

Quite a difference, could the regular bearings be biding the Y-Axis movement somehow causing vibrations and subsequently that ringing? Anyway its still not perfect.

Do you guys think i should change the X-Axis bearings to IGUS bearings too? I have more of them here!

Thats great to see! Looks like mine did after swapping you could try printing this test to see how your X, Y and circles look. My IGUS too had a little bit of side play which is why I wouldnt like them long term but it shows how the binding can affect the print. I swapped my X with some spare bearings a friend had and it didnt help with quality that much however my belt is rubbing so I'm going to work on eliminating that as a cause for the X ringing but it would be interesting to see if that did eliminate your X ringing, good luck if you decide to attempt it!

I've also got some PSFJ8 hard chrome plated smooth rods and bearings coming from Misumi to try for my X and Y but they wont arrive until the 9th. Will keep you posted if I sort out the remaining X issues

Re: poor print quality

Thank you Jason.

Well... just to test it out i decided to change the Y-Axis bearings... I swapped them for the IGUS RJ4JP-01-08... These bearings have a minor side play in the smooth rod... The regular LM8UU also have it but it seems to be less noticeable. Previously i had a Skew of 0.10º, now i have 0.13º. Not that much of a difference and i'm not sure if its the IGUS bearings fault.

So, anyway... i decided to make two prints with the "old" settings where i got ringing problems.

This is with the regular LM8UU bearings:

And this is with the IGUS bearings:

Quite a difference, could the regular bearings be biding the Y-Axis movement somehow causing vibrations and subsequently that ringing? Anyway its still not perfect.

Do you guys think i should change the X-Axis bearings to IGUS bearings too? I have more of them here!

Thats great to see! Looks like mine did after swapping you could try printing this test to see how your X, Y and circles look. My IGUS too had a little bit of side play which is why I wouldnt like them long term but it shows how the binding can affect the print. I swapped my X with some spare bearings a friend had and it didnt help with quality that much however my belt is rubbing so I'm going to work on eliminating that as a cause for the X ringing but it would be interesting to see if that did eliminate your X ringing, good luck if you decide to attempt it!

I've also got some PSFJ8 hard chrome plated smooth rods and bearings coming from Misumi to try for my X and Y but they wont arrive until the 9th. Will keep you posted if I sort out the remaining X issues

Ok, good! Cant wait to see your results.

I too have the belt rubbing on the idler. Im going to try and solve that once and for all. I will test IGUS on the X-Axis too to see the difference.

Re: poor print quality

I forgot to mention.. when I changed the Y bearings to Igus for testing; I also noticed that the Y idler was rubbing and not square. The directions have you use the 2 bolts to use for "tensioning" and mine were left a little loose to prevent over tightening the belt. This allowed the idler to twist a bit.

I added a tie wrap as a 'shim' to square it up without over tightening.. it seems to be tracking very well now and stopped squeaking.

Ron

Re: poor print quality

Hi Ron,

Thanks for the tips.

I just installed the IGUS on the X-axis... i barely tightened to avoid too much binding on the bearings but even like that the IGUS have more drag than the stock bearings....

I can feel its harder to move the carriage, but the selftest completed without a problem.

Regarding print quality i didnt see much improvement, if at all. The Y-axis bearings was what made the most difference.

I still need to make more tests to see if i'm gonna keep the IGUS on the x-axis or not.... i like it being dead silent but i dont know if the added resistance to x-axis is something worth considering, because despite having more resistance the movement is really smooth.

Re: poor print quality

I may have discovered something that may explain both the squeaking X belt and the vertical lines. I thought I had fixed my squeaky X belt by moving it back a bit. But it is still noisy. I looked at the offset along the rod and it should be centered but it drifts to one side as it gets closer to the X end. So my theory is the pulley axis is not aligned causing it to pull to one side. This causes rubbing and squeaks, but also can catch the edge of the belt teeth, creating a spatial harmonic. I measured the vertical lines on a print and it looks plausible, but possibly coincidence. Here is an exaggerated pic to explain:

belt.png

I feel the bearing change is a red herring. I've seen many inconclusive threads about IGUS. My MK2 was stock bearings and printed like a champ. I still think my belt rubbing theory is promising. I ordered new 623 bearings and will print a new toothed pulley with more clearance to test it out.

Re: poor print quality

I may have discovered something that may explain both the squeaking X belt and the vertical lines. I thought I had fixed my squeaky X belt by moving it back a bit. But it is still noisy. I looked at the offset along the rod and it should be centered but it drifts to one side as it gets closer to the X end. So my theory is the pulley axis is not aligned causing it to pull to one side. This causes rubbing and squeaks, but also can catch the edge of the belt teeth, creating a spatial harmonic. I measured the vertical lines on a print and it looks plausible, but possibly coincidence. Here is an exaggerated pic to explain:

belt.png

I feel the bearing change is a red herring. I've seen many inconclusive threads about IGUS. My MK2 was stock bearings and printed like a champ. I still think my belt rubbing theory is promising. I ordered new 623 bearings and will print a new toothed pulley with more clearance to test it out.

I never used it before... because i never felt the need with my other printer, but i had them here for quite some time.

I figured i could give them a try.... Still doing tests.... trying to find something "wrong" with them. The only thing that was concerning me was the additional drag on the X-axis but as it seems even that drag may help dampen vibrations and such.

Another thought of mine was the additional drag making the x-motor heat up more than usual since its working harder. It's been printing for an hour and everything seems fine and its not hot at all.

Re: poor print quality

UPDATE:

I decided to try a big print this time....

I'm happy to report that the print was just "PERFECT", no ringing, no vertical lines, just smooth lines all the way to the top.

I had an accident about 70% into the print... it kinda scared me but the printer was able to recover...... i have the spool hanging up higher than the printer itself... its on a spool holder with bearings but something made it topple and it came crashing down.... luckily it didnt hit the printer but as the spool came down to the floor it pulled hard on the printer making it "jump" out of place.. i was close but only heard the noise, when i went to see what was going on the spool was on the floor, printer with one feet out of the table and she was re-homing.... as the re-homing finished (i was literally with the printer mid-air putting it in it's place) she started printing again but immediatly stopped and re-homed again... after that she started again and finished the print no problem.

You can clearly see one layer line that's missing when the accident happened, in fact i think that layer was completed, it looks like it didnt print the outer-most layer... At first i thought it was a shifted layer and that the printer wasn't able to recover but the top part of that "missing" layer aligns with the bottom so im not completely sure what happened... And to be honest this was not a accident that usually happens so i'm quite happy the printer was able to continue with the print.

Anyway... less blabbering and more photos:

Re: poor print quality

UPDATE:

I decided to try a big print this time....

I'm happy to report that the print was just "PERFECT", no ringing, no vertical lines, just smooth lines all the way to the top.

I had an accident about 70% into the print... it kinda scared me but the printer was able to recover...... i have the spool hanging up higher than the printer itself... its on a spool holder with bearings but something made it topple and it came crashing down.... luckily it didnt hit the printer but as the spool came down to the floor it pulled hard on the printer making it "jump" out of place.. i was close but only heard the noise, when i went to see what was going on the spool was on the floor, printer with one feet out of the table and she was re-homing.... as the re-homing finished (i was literally with the printer mid-air putting it in it's place) she started printing again but immediatly stopped and re-homed again... after that she started again and finished the print no problem.

You can clearly see one layer line that's missing when the accident happened, in fact i think that layer was completed, it looks like it didnt print the outer-most layer... At first i thought it was a shifted layer and that the printer wasn't able to recover but the top part of that "missing" layer aligns with the bottom so im not completely sure what happened... And to be honest this was not a accident that usually happens so i'm quite happy the printer was able to continue with the print.

Anyway... less blabbering and more photos:

Looks really good now! Did you also check your belt if it was rubbing when you changed to the IGUS or do you think its the bearings thats eliminated the ringing? Has anyone tried the Misumi shafts and bearings yet? I'm hoping that they have better tolerances (g6 if i recall) so less vibrations but if not then I guess its back to IGUS for both X and Y....only concern is the slight wiggle I have on my Y with the IGUS and I here you have to replace them more often not sure how true that is if you keep the rods oiled.

My biggest concern is are all the traditional LMU8 style bearings going to cause ringing issues due to vibrations ? Did we just get a dodgy batch, not tightened the right screws or something we overlooked when building the kit or is it an inherent problem with the new MK3 that can only be over come by the IGUS style drylin bearing. There are lots of new MK3 owners on Facebook that seem to be printing without any problems or is this there first printer and don't have anything to compare it too.

Hope this didn't come across as negative I absolutely love my MK2s and the Prusa Team have always gone above and beyond when I have had issues and very quick sending out replacements. Just want to figure out if this just an isolated issue with a few MK3 kits that got sent out or something I did wrong when building the kit.

Re: poor print quality

UPDATE:

I decided to try a big print this time....

I'm happy to report that the print was just "PERFECT", no ringing, no vertical lines, just smooth lines all the way to the top.

I had an accident about 70% into the print... it kinda scared me but the printer was able to recover...... i have the spool hanging up higher than the printer itself... its on a spool holder with bearings but something made it topple and it came crashing down.... luckily it didnt hit the printer but as the spool came down to the floor it pulled hard on the printer making it "jump" out of place.. i was close but only heard the noise, when i went to see what was going on the spool was on the floor, printer with one feet out of the table and she was re-homing.... as the re-homing finished (i was literally with the printer mid-air putting it in it's place) she started printing again but immediatly stopped and re-homed again... after that she started again and finished the print no problem.

You can clearly see one layer line that's missing when the accident happened, in fact i think that layer was completed, it looks like it didnt print the outer-most layer... At first i thought it was a shifted layer and that the printer wasn't able to recover but the top part of that "missing" layer aligns with the bottom so im not completely sure what happened... And to be honest this was not a accident that usually happens so i'm quite happy the printer was able to continue with the print.

Anyway... less blabbering and more photos:

Looks really good now! Did you also check your belt if it was rubbing when you changed to the IGUS or do you think its the bearings thats eliminated the ringing? Has anyone tried the Misumi shafts and bearings yet? I'm hoping that they have better tolerances (g6 if i recall) so less vibrations but if not then I guess its back to IGUS for both X and Y....only concern is the slight wiggle I have on my Y with the IGUS and I here you have to replace them more often not sure how true that is if you keep the rods oiled.

My biggest concern is are all the traditional LMU8 style bearings going to cause ringing issues due to vibrations ? Did we just get a dodgy batch, not tightened the right screws or something we overlooked when building the kit or is it an inherent problem with the new MK3 that can only be over come by the IGUS style drylin bearing. There are lots of new MK3 owners on Facebook that seem to be printing without any problems or is this there first printer and don't have anything to compare it too.

Hope this didn't come across as negative I absolutely love my MK2s and the Prusa Team have always gone above and beyond when I have had issues and very quick sending out replacements. Just want to figure out if this just an isolated issue with a few MK3 kits that got sent out or something I did wrong when building the kit.

I have always used regular LM8UU bearings without any issues....

When i replaced the X-Axis bearings, i also tried to minimize the rubbing of the belt on the idler.... it still rubs on it... but much less now... it doesnt make any noise anymore but i can still see it lightly rubbing on it.

The biggest difference was when i changed the bearings on the Y-Axis..
Before this last changes i was also considering removing the rubber feet and use a rubber mat i have here to absorb vibrations.

This last print i made, i also changed the print settings, so its the bearings + print settings.

Perimeter Speed - 50mm/s
Outer-Perimeter Speed - 30mm/s

Nº of Perimeters - 3

Perimeter Acceleration - 600
Infill/Perimeters Overlap - 15%

Adjusted Extrusion Multiplier with this: https://www.thingiverse.com/thing:1622868 (have been using this stl for quite some time with other printer and filaments with good results)

Dropped the printing temperature to 200º for First Layer and 195º for the rest of the print.

I think thats all 🙂

Re: poor print quality

Well my rods and bearings arrived from Misumi this morning and I’ve swapped them over. As you can see from my same test print I no long have any issues on my X or Y yay! Everything seems to be working just as good as my MK2 now.

I also spent time making sure the X belt was better lined up at the back and that no longer rubs or squeaks anymore

Currently printing Marvin as a final comparison

Re: poor print quality

Well my rods and bearings arrived from Misumi this morning and I’ve swapped them over. As you can see from my same test print I no long have any issues on my X or Y yay! Everything seems to be working just as good as my MK2 now.

I also spent time making sure the X belt was better lined up at the back and that no longer rubs or squeaks anymore

Currently printing Marvin as a final comparison

Did you pack the bearings prior to installing them? If so what did you use?

Re: poor print quality

Well my rods and bearings arrived from Misumi this morning and I’ve swapped them over. As you can see from my same test print I no long have any issues on my X or Y yay! Everything seems to be working just as good as my MK2 now.

I also spent time making sure the X belt was better lined up at the back and that no longer rubs or squeaks anymore

Currently printing Marvin as a final comparison

Did you pack the bearings prior to installing them? If so what did you use?

Just white lithium grease

Re: poor print quality

Wow, so jealous of your ring-free prints! I get ringing on pretty much every print where there is a hole or sharp corner. Reducing print speed helps, but doesn't completely solve it.

The prints still look great. A laymen/regular person would probably not notice ringing at all... but it stands out to me, since its my own printer.

Could you print a Benchy with the standard 200um settings in Slic3r PE? I'd be really curious to see how your windows and doors turn out... my get some pretty prominent rings.

Re: poor print quality

Well my rods and bearings arrived from Misumi this morning and I’ve swapped them over. As you can see from my same test print I no long have any issues on my X or Y yay! Everything seems to be working just as good as my MK2 now.

I also spent time making sure the X belt was better lined up at the back and that no longer rubs or squeaks anymore

Currently printing Marvin as a final comparison

That's looking good.

Keep us posted as you make more and more prints!