Cube corner looks bad (incomplete?) at layer change.
Printing a 20mm cube, delta printer, PLA 200C. Looking down from above, 3 corners look fine (1st photo), but the 4th corner where the layer change happens looks bad - like it didn’t print the entire corner (2nd and 3rd photo).
Using S3D, experimented with extrusion multiplier (0.8 to 1.0 to 1.1), coasting (0.1mm and 0mm), nozzle wipe (5mm and off). I can’t get that corner to print cleanly.
Any ideas?
Which firmware are you using? Also, hot bed temperature matters. Make sure it is hot enough.
Bed temp isn’t going to affect upper layers there. As the issue persists through the upper layers, it’s not related to bed temp.
I am giving coasting upto 0.4mm. Gives better results
@Ernesto_Martinez firmware is Marlin 1.1.0 RC8. No heated bed but agree with Derrick that that isn’t the problem in this case.
@Selvakumaran_Ganesan will try longer coasting tomorrow but since the problem seems to be a lack of plastic in the corner I’m not sure how long coasting would help - seems like it might make problem worse.
@Fred_Hamilton , have you tried the RCBugFix branch of RC8? It has lots of improvements.
Did you set the Outline direction to Inside-Out? This should move the seam to the inside.
Another trick with S3D is to tell it to start at random points on each layer.
Thanks Ernesto, Derrick, Selva, Christoph! Catching up:
Actually I am already using RCBugFix, not RC8 (my mistake)
I was using Inside Out; will try Outside In right now. Update: Outside In looks worse…
Random points just distributes the error over all 4 corners so I disabled it to focus on the problem. Will probably re-enable once I’ve reduced the magnitude of the issue.
Watching it while printing, is the problem happening at the beginning of the printing of the corner, the end of the printing of the corner, or both?
I’m curious. It appears to be not adhering properly at the start and end of the extrusion of the layer, and pulling out a bit. As the problem doesn’t exist in the first layer, and gets worse quickly until it gets to a constant point a few layers away from the bed, I suspect that may be the case.
If so, maybe just increasing your nozzle temp by a few degrees would solve the issue?
Retraction is enabled, but it’s not retracting since I don’t have “Force retraction between layers enabled” (I guess I could see what happens with that enabled). PLA, no part cooling fan.
One thing I should mention is that I used to be able to print perfectly with the original Marlin 1.0 and DeltaMaker print head / 0.35mm nozzle. I switched to an E3D Lite6 with 0.4mm nozzle and haven’t been able to get back to the same quality yet.
@Fred_Hamilton , I suggest you turn off coasting in S3D, and turn enable LIN_ADVANCE in Marlin.
This controls the pressure in the nozzle, and can be adjusted by the K which if a factor.
Start with K=150 and go up 50 for every try until you see the corners are perfect.
It’s in the Advanced Config file…
You can also turn down the retraction as pressure won’t built up so much on the hotend.
You should also be able to print faster with less/no artifacts.
@David_Sherwood I did adjust e steps/mm so 100mm = 100mm, but didn’t do the single wall test. I could not figure out how to get S3D to generate a single wall. Thought it would be easy but it ain’t. May try slic3r or cura. I did adjust extrusion multiplier from 0.8 to 1.1 and while cube characteristics changed as expected, corner still looked like crap. Tried 180, 190, 200 and 210C - corner still looked bad.
Will try slowing down print speed next.
@Panayiotis_Savva I am interested in trying LIN_ADVANCE (we talked about it a few weeks ago), but not sure it would help here since I’m not retracting. So I want to sort this basic thing first.
@David_Sherwood Appreciate the guide! Cube came out looking great - no corner distortion (you can’t tell on which corner the layer changed). 0.40 mm to 0.41 mm on all 4 sides. Big difference seemed to be the print speed since it slowed way down for the short layer time. Will try printing one of my original problematic cubes at a lower speed…
I have been tuning LIN_ADVANCE in RC8 RCBugFix branch, and I can certainly see big improvements in print quality.
Cool
