After creating some Laser Projects im Back to 3d printing.
I have follwing problems.
In the first case I think that lines are normal for FDM printers, but i am not sure if they are too strong / out of specification in my case.
I made two prints. The above one is without backlash compensation, and the second one (downside) is with Backlash compensation set to 0.02
The second case is that my print bed got some bulges from the form of the object - but i think it has to do with the print temperature of 225 CĀ°. Is it possible to iron this out somehow?
Youāre positive thatās a backlash comp of 0.02 and not 0.2? 0.02mm is so small, that would not explain those lines.
Can you grab everything and gently wiggle, make sure thereās absolutely no motion at all? Toolhead, bed, etc. Sometimes a small amount of movement creeps in if the internal module rollers loosen up.
If itās not something mechanical, then it may be related to print speed, acceleration+jerk settings, linear advance, and a whole host of other possible causes.
Were both of those prints the same temperature? The bottom one looks shinier to me, like it was printed at a higher temp. Could just be the lighting.
The problem Iām having trouble explaining is the consistency of the bottom lines - they are constant for a whole layer. Specifically here, even as it rounds the corner:
In order for this to be explained with software (even firmware) the explanation would have to address what is essentially the machine consistently being wrong, yet also explain the top print, which is hard to do.
What filament are you using? Itās possible the filament diameter is varying and this is all just a coincidence. Could you scale that model down to like 25% or something and print a whole bunch (like 4, doesnāt have to finish) with the same exact same settings? Just enough of a print to gauge the lines? Maybe do 4 small samples with backlash off as well? Iād imagine each print wouldnāt take more than 10 minutes to be able to tell. Each print needs to be sequential, one after the other. Printing all 4 at once wonāt tell anything.
It could be a partial clog, sometimes they do stuff like that.
Whatās weird to me is it got worse over 1 print. Iām curious if itās oscillating back and forth, or constantly bad now. If itās oscillating, could be filament related. If itās constant it could be a clog. If itās better without backlash and worse with backlash consistently with more testing that would be a new finding.
Would you mind posting numbers for that filament? At least 20 diameter measurements, at 10 spots, spaced out 3 feet each (30ft total), orthogonal to each other to measure how out of round it is.
Way overkill for good quality filament, but since thatās the question hereā¦
I donāt recall what slicer youāre using, but with S3D I would drop the bottom chamfer through the floor to get rid of that, scale it down to roughly 50mm or so, and then use a horizontal expand to correct for the wall thickness so nothing changes thickness-wise. Then have it end slicing at about .5" high or something, since the issues seemed to be present in the first few layers.
That is similar to the problem I haveā¦ Still didnāt figure out what is wrong, checked multiple things, but still no clue! I hope you will be luckier than me @Slynold, to try your solution!
Oh my, itās been 2 full weeks since your thread. Your issue is bizarre to me because it seemed more focused on the particular model you printed. This issue looks more randomly distributed. Maybe not, just a guess.
I did multiple prints and recalculations since thenā¦ Checked backlash (now I know what it is), changed filament, nozzle, recalculated e-steps and k-factor, but still nothingā¦
It is not for that specific model, it is general. I have more photos on the top of that threadā¦ So this might indeed help!
What I didnāt check though, now that I am thinking about it, is try a different slicer (in case this is a cura weird issue) and re-build the machine from the beginning!
In any case, I am still noob, so I might be doing something wrong and donāt know what it is, but heyā¦ What can I do!?
Those tolerances are actually great, unfortunately I donāt think that explains it. Prusament is extremely high quality, tight tolerance, filament - its spec is +/-0.02mm. You are measuring a tolerance of +/-0.02mm. Typical manufacturing tolerance is +/-0.03mm to +/-0.05mm.
At least I think that pretty conclusively rules out backlash as the issue.
I agree with @sdj544 - it could be ghosting or ringing, could temporarily lower the acceleration limit to like 250 for a test, maybe reduce junction deviation to 0.01? This can be done on the terminal and you donāt have to M500 save it - then you can just reboot to reset it.
Edit:
In the terminal (wifi or USB) or at the start of the gcode file manually or in the Cura starting code.
