RE: Tiny holes in printed walls
Probably so.
After reading your other post, have you examined the g-code at the layers in question?
You have stated that the problem does not exist for ‘case mode’ - a single perimeter with one long extrusion.
So if the problem exists for a ‘normal g-code’ - the you should look for the difference in the code.
One of the claimed fixes was that it was a ‘retraction’ problem. Even though it occurs at a spot where you would not expect a retraction.
So perhaps the designer has put some fancy g-code in the slicer that causes an extraction problem at regular intervals.
RE: Tiny holes in printed walls
Hi all,
thanks for all your replies.
@nickatnight: I think issues with the mechanics as well as the filament can be ruled out, as the pictures show prints from different machines and different filaments. So the error must have been in the gcode somehow. Then again, one of the machines didn't have the issue with the same gcode (and same firmware etc.). It remains a mystery to me. Thankfully it kind of solved itself eventually. With newer iterations in the design of the printed object, it was sliced anew and new gcode was generated. With each new gcode the issues sometimes showed up at another spot, more often they were gone entirely. And no, there was no apparent link between the areas where the design was changed and the areas the tiny holes showed up.
So I'm guessing it's just bad luck? When it happens again, I try moving the object around on the build plate, slice again, until the holes are gone. Oh well.
RE: Tiny holes in printed walls
It may be the filament !
Just printed a few Prusa whistles to test the MMU2S and eliminate some old filament.
All of the white whistles had this effect. None of the others did.
RE: Tiny holes in printed walls
Hi Folks,
Problem solved on my printer. I think the best way to solve this is by using "pressure advance" parameters. There is ton of infos on this on internet, and the way I fixed this let me think it's a pressure issue happening in the extruder.
I print using a 0.8mm nozzle, when I print 0.75mm width walls with this nozzle, the issue disapear. So I guess it's relevant to say that the pressure there is in your extruder could cause this holes. Reducing rectractation to 2mm or less would also helps, because if you retract to much you have too much pressures change in your nozzle and it will cause this.
Hope these infos will helps somes 3D printerers 🙂
RE: Tiny holes in printed walls
Interesting you talk about extrusion pressure. New to owning my own printer and just saw a video on testing printer extrusion for speed and the tests were to run the extrusion speed up until the amount of material extruded was starting to decrease. Sort of a Poop test from what it looked like. The video was related to CHT nozzles and print speeds but sounds related to what you are saying. It sounds like a good test to find out how different nozzles and filaments work to optimize for speed.
RE: Tiny holes in printed walls
Hi. I have the same issue on all printers Creality and Tenlog with prusa and cura.
I print a 30cm long constant outer wall and the holes are on one area about 2cm randomly spreaded.
If I switch the filament from other brand the holes move to an other area but with same 2cm randomly spreaded.
This is a mystery for me. Parts I printed one day before look different with less holes.
Water can not be: the holes are on one area 2cm. The rest outer wall is perfect.
Extruder problem should be the same. The distance from start to holes is about 3cm away. But will check today.
Very strange. Seems to be needed to analyse by an expert.
Really!, the outer wall is around 30cm with constant 40mm/s. Outer wall first. But holes on one spot 2cm randomly over nearly all layers.
RE: Tiny holes in printed walls
Solved:
Direct Extruder Retract 1mm at 30mm/s reduction
RE: Tiny holes in printed walls
I encountered this issue with my MK4, tried a lot of different settings(cooling, retraction, seams etc) but nothing helped. When i changed from 2 to 4 walls, the problem almost dissapered. There is still small bumps if you look closely, but the print is 90% better.
RE: Tiny holes in printed walls
My problems with the MK4 continued and i started to get missing lines in the prints at random places. The problems all went away when i stopped using Prusa Connect, i now transfer files with USB to the printer, and prints all look very nice.
RE: Tiny holes in printed walls
The problems all went away when i stopped using Prusa Connect, i now transfer files with USB to the printer, and prints all look very nice.
This points to a buffering issue in the connection. I ran into this with a laser etcher some years ago and changed the design to provide more buffering, moving from an Arduino Uno to a Mega. Not familiar with the Mk4 and Prusa connect, was the connection via USB or Ethernet? USB connections are not real time and depending on the computer, can be very slow. Also depends on the number of devices on the USB controller chip.
On my MK3s+, I use a Orange Pi Zero 2 as the server. Best move I ever made. Thanks to those on this forum that recommended it.
RE:
@sandysasmita https://forum.prusa3d.com/forum/postid/604692/
thank. you. so. much. for. this. You truly made my day!