Help with print quality

[roybfr]

As of late the print quality on my i3 8" has gone down and I can't seem to figure out why.

Basic stats - i3 (non v) 8" running 1.75 J-head with .40 nozzle, printing ABS at 225 on to kapton bed coated with hairspray, bed is at 110. Using Slic3r 1.1.7 but get same results from Cura. Filament settings in Slic3r are diameter 1.68 wit ha multiplier of 1 (this could be part of the issues based on some reading), layer height of .3, infill 15%, speed at 60 for infill, 45 for perimeters, 2 shells. Retraction settings are1mm, speed 30mm, min travel 2mm



Here is the print. The main body is ok but could be smoother. But the stand highlights some of what I see, lack of smoothness, globing, etc.

I have done through and tightened up every thing. I had some be slop in the bed from the nuts on the threaded rods loosening over time. That is now gone, alone with anything else that had loosened over time. I slowed my prints down, and tried different filament. While things have gotten a little better it is just off from where I was at a few months back and I can't seem to pin point the issue.

Is my extruded just clogged? Any other ideas.

[AbuMaia]

I encounter the same issues when printing narrow, tall objects like the stand. The problem is the previous layers of plastic aren't cooling fast enough to be a solid base for the next layer. Add a print cooling fan, and it should help.

[printbus]

I agree with AbuMaia. If you don't want to add a print cooler due to ABS curling issues, try printing multiple copies of the base at the same time. You don't mention what you are using for minimum layer time and minimum print speed, but the right combination of slicer software and settings can actually force the nozzle to lift off the print as necessary to meet the minimum layer time while still keeping the actual print speed fairly high. You don't want the print head to just keep going slower and slower as the post on the base gets smaller.

I'd also drop the retraction speed to 10 or 15mm/sec. I know Colin distributes the Slic3r config files with it set to 30mm/sec, but that's asking a lot of Marlin and the extruder motor.

[roybfr]

In Slic3r I have auto cooling enabled with the Cooling thresholds set at

Enable fan 60 (no fan at this time, use one on my MM 1.5 since its used for PLA)
Slow down 30
Min print speed 10mm/s

I believe these are defaults as I don't recall changing them. I have changed the retraction settings and will try the print again to see if that helps

[AbuMaia]

I think if you increase your minimum print speed to at or just under your normal print speed, it may force slic3r to lift the nozzle and wait for the minimum layer time to elapse. But I'm not sure on that, I've never tried it.

[gmay3]

Hi roybfr! Did you try any calibration procedures from the sticky yet?

[roybfr]

Yes when I first got the printer last year I went through all of the calibration and for a long time things were good. But something has gone away and I am having a hard time figuring out what it is. I am going back through calibration items over the next few days and hope with some of that I can get it back to where it was previously.

[roybfr]

So I adjusted my e steps to 889 after after doing several extrusion test measurements. Did a few 20 mm cube prints and at least on the first few layers I was still getting a bit of excess. Doing a new print with with a slightly lower extrusion multiplier and changing first layer default with from 200% to 105%, looks better so far.

[gmay3]

So I adjusted my e steps to 889 after after doing several extrusion test measurements. Did a few 20 mm cube prints and at least on the first few layers I was still getting a bit of excess. Doing a new print with with a slightly lower extrusion multiplier and changing first layer default with from 200% to 105%, looks better so far.

Good to hear.

It's completely normal that print quality might decrease over time. In addition to regular tightness/structural issues, I think the filament width coming off the spool can vary as you get deeper into the roll. Also since the extruder gear parts are 3d printed and constantly wearing, they will change over time and cause your extrusion multiplier to vary.

I'm still on my original extruder gears from makerfarm from April 2014 printed at 0.3mm layer height and I'm looking forward to swapping in a fresh pair of 0.2mm layer ones I recently printed with a 0.3mm nozzle

[roybfr]

Thanks again for the help. I am still on my first set of extruder printed parts as well, they do wear, surprised how long they have lasted.

Now I just need to get my auto bed leveling setup installed and new firmware loaded (with EPROMM saving enabled and new Esteps). Not sure if it is the wood or maybe the springs, but bed needs to be re-leveled every few prints. Never moves much but just enough to muck things up.