I’m sure some of the 3DP veterans would know what the issue is here… I’m getting some roughness in my prints. This is with ABS. The weird part is, it doesn’t do it on every print and if you notice, some area’s print fine, some not so good…really weird, almost makes me wonder if it’s something to do with the filament… The one that looks slightly nicer was at 230C, bed 99. The really rough one’s were 235, 110C, which is what I normally cook with so not sure what’s going on. Seems like it got worse…
These parts were .25 layer height(.35 nozzle), interestingly, I just printed a tiny part with .15 layer height prior and it came out looking great, but I’ve printed at .25 layer height a million times before with great results…I’m wondering if it could be cross contamination with stuff lingering in my nozzle, other filaments etc?
all insights are welcomed! Gotta get these prints dialed in, they need to look perfect, they will be going up for sale.
another issue is that I’ve started using the LCD lately(SD card). Think I’ll plug in and try to run the same prints on Pronterface to help narrow down the cause.
Looks like a couple of minor calibration issues. That’s a long skinny part, and the layer issues you are seeing are in the areas where it is transitioning to a much different layer profile, where it goes from the whole part to just the upper structure, where it meets the holes, etc.
For starters, I think it is possibly overextruding slightly. You might try bumping up your filliament diameter modifier slightly and reprinting. If you are using Slic3r, since it is such a narrow part. you may want to make sure that “enable auto cooling” is turned on. It was off by default in some slic3r profiles. I’d also see if it is set to print the outer perimiter first, and set it to print at least 3 perimiters before infilling.
It also looks like you might have had a tiny bit of lifting on the inner edge of one of the parts. That could be an artifact of the part removal process, but it might have been enough to cause an issue given how skinny the part is. You might try printing it with a 2-3mm brim layer if you aren’t already.
Another thing it could possibly be is nozzle wobble due to a worn bearing, somethign loose, or something out of allignment. If you have that, you can usually see it in a large flat first layer area. it often shows up as a wavy first layer surface, especially towards corners or along long travel paths at the edge of the highest point of acceleration. Overextrusion can also cause that symptomatically because the print nozzle ends up with too much plastic and no where to put it, so it forces it up slightly until the overpressure is released. If thats the case you’ll see excess material buildup in sharp corners.
if you thicken that part another mm or 2, it will probably print easier.
I plan on doing some tests to figure this out, but I just did a quick measure of my filament dimaeter, and I’m getting crazy values from 2.75-3.00mm within a few inches between measuring points, and some area’s are thinned out, if I roll my caliper around in one place it will go from 2.7 to almost 3mm meaning it’s not round. It’s looking like the end of this roll of ABS has some tolerance issues…maybe a worn out extruder nozzle…
when setting filament diameter in slic3r, is it better to air on the larger or smaller side? How exactly does that parameter affect the extrusion…??
Peircet, I really appreciate the thorough response, the more idea’s the better, I have most of the those things checked off the list, but the whole corner lifting thing is just an optical illusion because it’s sitting on a piece of acrylic on the table top, I used a 10mm brim and it stuck like glue so no warping or lifting at all… you’re right though, just a calibration issue, it does look like it’s over extruding in those area’s, I’m going to recal the extruder tomorrow.
meh, loose bearing issue is low on the list, everything is pretty tight and it would have showed up in that other print I did with the .15mm layer height, that came out so perfect I could have ate it with some whip cream and a cherry on top.
I also noticed that the end of this roll of ABS is extremely out of tolerane, as mentioned in my previous post so not sure if I can fix that issue but the results I’m getting, ie fine some layers, then blobby at random times would make sense if the filament was out of tolerance… also, I’ve printed with this roll prior to this without issue so something changed along the way. I’m going to adjust the retraction settings also. Just going to try a bunch of things tomorrow and report back.
if anyone has any other idea’s, keep em coming, iz more than appreciated!
thanks guys.
Looks like a bit of “erratic” extrusion and perhaps too high melt temp.
Erratic extrusion can happen when the filament snags along the cold path. That creates excess back pressure and when it finally pops free (this all happens in fractions of seconds) it exerts excess force on the melt, cause a little over extrusion blob. If the part were consistently blobby I would say over extrusion but this part seems to have areas of blobs and areas of gaps. Inconsistent filament diameter can do this - especially if the size is too large and it is snagging somewhere. See my recent post where I discovered the aluminum mount between the extruder and Budhashnozzle was snagging my filament.
The other way inconsistent filament diameter can impact this is at the extruder - thin diameters may not be gripped as well and actually slip. Again, resulting in gaps succeeded by blobs.
Check the filament path through your extruder and hot end.
If you have very inconsistent filament the best bet is to take 10 measurements and average them. Test on a piece and then adjust. It can be challenging since the inconsistencies may not be uniform over the length of the filament.
well look who it is, …ya know, I was sorta hoping you would come along and find this thread. 
you’re word is golden on this stuff so thanks. I’ll look into all those things… yes, snagging could be a very real possibility as the roll dwindles in size, I also like the theory about the off sized filament not gripping well on the extruder bolt, all very logical reasons. I’m pretty sure filament that goes from 2.7-3mm is not very standard? right? Just seems to have gotten worse towards the end of the roll. I might give the supplier a call. Would it be better to overshoot or undershoot when setting the filament size…? thank you for helping with this…ehem… persnickety situation.
2.7 to 3.0mm is a BIG variation for filament. Do you have any other that you can test?
Under or over- shooting both have their issues. Under and you get an incomplete part, maybe week bonding, etc. Over- and you get a bigger part, maybe blobbing or oozing. I’d just do the 10 point average over 5’ of filament (measure at 6" intervals for a total of 10 measurements.)
Ok thanks…
Just remeasured this morning, it’s more like 2.8ish to 2.95ish, sometimes 3mm… still a pretty wide variation I would think. I have some Lulzbot HIPS here and the variation is like 2.9-2.95, which I think is acceptable. I’m getting the large variation with the other brand because it’s ovalized in some areas, I know that because I can see it and when I rotate my caliper around it changes 
. And yes, I have other filament I can use as a control test afterwards…
So I have a test print going now. Some of the changes I made were…
- tightened up the tesnsion screws, assuming the filament is uneven, should help grip the smaller diameters better.
- In Slic3r, adjusted retraction to 1.5, 50mm/s speed.
- In Slic3r, 2.92 as filament diameter vs. 2.85, brought travel speed down from 180 to 130 (reduce heat build up in motors)
- Recalibrated the extruder using the LCD, set to 890mm/s vs. 900mm/s. First time I’ve done this on the LCD, didn’t think I needed to because I had good prints before. Or maybe since they were larger prints, the blobbing was just not as noticeable. Now it’s BANG on.
If I get the similar results, I’m going to keep all these settings and then try a few different ABS filaments to see what happens there. It’s a matter of picking off each parameter, gotta be scientific with it.
Alright guys, so considering all the adjustments I made (detailed in my previous post). Here is the outcome. Looks like I’m on the right track… the blobs are gone, only thing now is some slight area’s of under extrusion, but overall layer bonding seems good regardless. The print came out clean enough that I could slide fit parts, which is what I want.
The little part was from a seperate print, .15 layer height.
How is this part oriented on the table as it prints? It now look like you have some layer misregistration. This is usually from either loose belts or slipping pulleys on the steppers. Sloppy guides can also contribute. If it is aligned in X or Y primarily it gives you a starting place to look deeper.
It’s printed inverse of how it’s sitting on that table, so the upside on those pictures is sitting flat down on the bed…
Yes, I noticed that, but for me personally, I find the finish ok. I think the light makes it seems worse than it really is. But can you explain further, I’m open to trying to dial it in to perfection if the fix is not that complicated…
My Taz is only a few months old, there’s very little play in anything. Just noticed recently that the x carriage polymer bushing has a slight amount of play(polymer bearing to shaft, not bearing to holder) but you have to push on it really hard to get it to budge so I don’t think that would cause it.
I have a bunch of prints prior to this, circular round prints and others that have pretty good layer alignment…
I’m comparing to some prints I did when I had the mini lulzbot and I have to say, they look about the same, maybe JUUUST slightly more rougher than the mini prints… so you think I can get it smoother than that? I have a feeling that would take a lot of tuning to the machine…
I meant how it is aligned along the X or Y direction. That will give a clue as to what might be going on.
Yes, you should be able to get it dead smooth. I don’t think it would take a lot of tuning, just find and fix the problem. It will continue to haunt and plague you!
Print something else that you’ve had good results with in the past and see how it comes out.
I used a bunch of steel extruded tubing to make a jig to align X and Y along time ago. Basically I squared Y with the actually X rods and not the frame…it came out to being a little skewed to the frame… But that is all tightened down and shouldn’t have changed. Plus if X and Y were skewed the prints would be skewed all the way up Z…in this case, we’re talking about layers not getting perfect alignment on each layer, sometimes randomly…
It looks like you are just slightly underextruding now. I’d bump it back up a notch or two, but it’s definitely an improvement over the first ones.
You might also have a slightly undertensioned Y axis belt. I find a belt tensioner to be a very worthwhile upgrade for that axis in particular given the weight of the heated bed. You may also want to look at the X axis. It looks like you have a bit of a wave pattern, very minor, on that side which can be caused by excess looseness. See if you can spread the bearings on the back of the X carriage either narrower, or further apart to make better contact with the bearing rods, tighten the belt and the extruder, etc. We’re talking a fraction of a millimeter deflection, so it isn’t going to take much.
Looking at the part now, it looks like you have a slightly oversized layer about once every 5 layers or so. I’d check your slic3r configuration to see if you have the setting for “solid infill layer every X layers” turned on, and if so, turn it off.
Yep. I’ll play around with the extrusion multiplier, my calibration is SPOT on, not a mm less.
doubt it’s belts, all are snug but will keep an eye out.
Like I said, the x carriage does have some play, but it’s only if it’s pushed on really hard, but I’d really like to get it fixed up, I have some LMu bearings on the way, I imagine I’ll need hardened rods though… I’ve tried pressing things to get it to tighten up but it only made it worse…
“Solid infill every X layer” has always been off.
I’ve just changed filament, re calibrated, I’m going to try it and see what happens.
Ok, so swapped filament for filaments.ca natural, fire resistant ABS. Calibrated everything to the tee. Overall a B+ quality print, absolutely zero ooze or over extrusion. So that problem is solved. Still a bit of layer alignment issues but I’m actually thinking it might just be G-code related as this part has a constant gradual curvature, just might be too much for the puter to process, because I’m pretty sure if I were to print a cube, the layers would be perfectly smooth, smooth walls. Ofcourse I’d like to get as smooth as a babies rump but I’m just not sure how…everything is pretty much tight, might be the x carriage though.
Anyway, with regards to the $hitty quality of the previous prints, check out the second picture of the end of the roll of grey Pewter ABS from filaments.ca. The whole roll gave me pretty good prints, but I’m sure the oozing and all the troubles are from this part of the filament roll. It started about that time…Look at all the white “stress” marks, you can actually see it ovalized. If I compare it to a new roll of Lulzbot filament, or even other stuff from fili.ca, there’s none of that, and everything is visually round with only about .05 to .1mm deviation. It’s like it had trouble extruding at the factory or something. Think I will give filaments.ca a call about this. There’s still about 1/3 of the roll left. What do you guys think?
thanks for all the feedback, helps ALOT! really invaluable.
The camera flash always accentuates any layer issues, so I think you are pretty well dialed in there. A bit more tuning would make it perfect but it should be quite usable.
THe lighter spot on the filliament happens when it gets bent beyond it’s stress point. You can reproduce that exact effect by bending a piece of that in a very tight loop. It can happen when spooling processes at the factory do not go entirely according to plan.
Yeah, I just realized that afterwards, about the filament, it’s just like that because it’s lower on the roll so it’s bent more…but I still think there’s something up with it, the measurements I get are all over the place… visually it looks oval also, maybe it’s got a bit of moisture in it also… i’ll keep paying around with the it, see if I can get it to work even better…
So I’ve decided that this post is pretty relevant to my current issue. I’ve been using the Taz 4 printer with much success for the past 3 months. It was until over last weekend where I my trouble began…it all began on Saturday, when my z axis would suddenly stall when trying to home. Did some googling to find out I should adjust my Z feedrate from 8 to 4, and that ended up fixing that issue. Later that day, a different person started a print (printing at an institute) and apparently the nozzle clogged and filament was oozing out of the tubing above the heating block, between the heatsinks. He took the nozzle apart, and cleaned out the filament. After that, my prints never were the same. I now have this issue where, as the layers build, the nozzle rubs against the hardened pla when traveling to different positions. At first, i thought it was a leveling issue, and I did a total releveling of my bed, still same issue. Next, I thought the extruder might be overextruding, i remeasured my filament, and reset my filament diameter from 2.85 to 2.98, still same issue. After plenty of frustration, I thought maybe when this guy cleaned out the extruder, somehow loosened something, where the extruder is now extruding thicker traces than it actually thinks its extruding. so i took it apart for myself, retightened the screws, and still…same problem. now i upped my filament diameter to 3.5 at this point, because what the hell, and the prints seems to come out a bit better. less rubbing of the nozzle above the pla, yet after a certain height, i start to get the same issue.
so heres some images and a video demonstrating my issue.
you can hear and see the rubbing midway through the video.
https://www.youtube.com/watch?v=qlLWSL5xCOI
these are the cubes i started to print to troubleshoot. you can see the first few layers are rough, and then it smooths out. also some curling happening which led me to believe it was an overextruding issue.
weird angle, but you can kind of see the nozzle is a bit lower than it should be. i’ve measure the distance of the bed to nozzle when above by 10 mm, and it all checks out. so ima bit lost…
help???
