One more thought that there may be a restriction in the feed path. The closest I’ve come to seeing something similar was related to spool tension. Every “x” % of rotation, the spool encountered some resistance in turning, which resulted in significant under extrusion for the period of increased tension.
Good luck tracking this down!
yeah, thought of that as well, i made a custom spoolholder that rides on bearings, it rolls freely with no tugging. i dunno. im starting to lose hope on this one
so lets say you do a tower, 5cm square and 100mm tall, you had said that you were seeing the bands approx. every 10mm high. If you increased the size of the tower to say 12mm square but still 100mm tall would the bands still be ever 10mm in the Z or would they get slightly closer together?
im gonna try this out. will let u know what i find.
thanks Jason
so i printed 2 boxes as per your specs. printed them no fill/spiralized. 0.2 layerheight on both
interesting results…the image speaks for itself…
Seems like it happens by filament length/time extruding. Extruder motor overheating?
seems like that to me as well, but how ? the stepper barely gets warm, im using Sakata filament that has pretty low diameter variance, and its pretty random, also i get the same results regardless the filament i use.
im starting to think this might be an electrical issue, but i wouldnt even know where to start checking that. the machines i build and components i use are in a different world compared to this stuff
Yeah, I’m not familiar with these parts either. If all your steppers are the same kind on your printer you could swap one and see if it changes things. The only other thin g I can think of is a bad power supply, these are more like computers than machines and voltage drops have weird effects. maybe monitor the output from the power supply?
nah, we dont use steppers, we use servos. i understand how steppers work but im not an expert by any means
im gonna print some different geometric shapes with the same settings, hopefully a pattern may arise that could spark some idea hehe
I mean swap like the X axis for the extruder stepper
hmm, i have dual Z…i could swap the extruder and Y stepper to the 2 Zsteppers.
i havent looked at them closely but im sure they are all the same correct ?
Well if they are you can swap them. The Y is a good candidate, If it’s alone.
ya, that’s kinda what I was expecting, its amount of filament extruded related. Not Z height
by doing that test we have eliminated the Z-axis altogether as being part of the issue.
problem is in the extruder. the funny part is it’s SO uniform and predictable.
At least you have 2 good test prints that will prove the problem is gone. Try this, slow down the print time to like 1/2. Use the exact same Gcode file but change the print speed to 50% to see if that changes it.
If nothing changes then change filament, if you’re using PLA switch to PETG or vice versa. Again same Gcode file just changes temp and cooling fan speed. Curious to see that change.
printing some tests right now.
all out of petg, would have to order some. but i have tried a variety of pla’s and it changed nothing.
what makes this so confusing, like you said is the repeatability of the artifacts
so, im seeing interesting results already…the slower the print speed, the tighter the banding.
im just slowing the print by percentage using the Printer interface.
have a baseline print at 40mm/s then another at 50% and one more at 30%
will post images soon
That would indicate time vs length that is extruded. interesting for sure. the intervals would be the same if you printed 2 parts with the same settings?
Wow. This just keeps getting weirder.
OK; Weird question - can you print the block scaled to 300% in X and Y, but keeping Z the same? I want to see if the banding pattern remains consistent.
I know this makes zero sense, but it’s almost as if there is a time component to this. It’s like you get a narrow band after time X which doubles the number of bands when the speed is 50% and triples it (approximately) at 30%. I can’t for the life of me think of a mechanism that would be time dependent, but if you print a 300% larger box of the same height, we’ll see if the the striping pattern matches the normal sized block at 30%.
il try this, gimme some time and il post a pic
Thanks, Lego
