Failed ABS print of a large circle with a lip... fails when making the lip
Hi all,
I have failed to print the above design several times. It seems to fail when starting to print the circular lip (see CAD picture). I do not think this is an adhesion or enclosure issue because it fails specifically when creating the lip (I could be wrong in my logic though). I have also successfully printed several other parts with the same settings. I believe this might be a top layer infill or perimeter issues. The wall thickness of the lip is 5mm. Anyone have suggestions? 
RE: Failed ABS print of a large circle with a lip... fails when making the lip
That looks like it should print with no problem on almost any printer.
If you will post the .stl file, I would be happy to slice it and see what I get. If I don't see any issues I'll try printing it with some tag ends and see what I get.
You will probably have to make a .zip with the .stl file in it to attach it here.
RE: Failed ABS print of a large circle with a lip... fails when making the lip
In what way does it fail - layer shift, stops extruding, loses adhesion?
Otherwise there is nothing tricky about the shape. Sometimes a bad STL causes problems for the slicer, but the slicer usually flags up any issues.
RE: Failed ABS print of a large circle with a lip... fails when making the lip
RE: Failed ABS print of a large circle with a lip... fails when making the lip
Let me take a look at it. If it looks good from the .stl perspective I'll probably print at least some of it to see what happens. I'll report back here when I know something.
RE: Failed ABS print of a large circle with a lip... fails when making the lip
Ok, I did a test print for a sanity check.
I didn't realize that was so large. Full-size it would have been a 9 hour print the way I sliced it, so I scaled it down to 33% for a sanity check. This is black Hatchbox ABS, which is what I have currently loaded for some other prints.
As you can see from the photos below, it printed close to perfectly. I'm showing views with and without the draft shield, which I almost always use for ABS prints of any meaningful height. The outer lip on the scaled version measures just over 1.5mm with the cheapie dial caliper. The lip is formed just as it should be in the original.
I am highly confident that this will print very well on almost any properly-operating printer.
Now, I didn't realize this was on a Mini, and I don't have a Mini, but in looking closer at your photos, it looks like there's a 'ghost' image of the center circular pocket just to the left of the actual pocket. There are also some other artifacts on the topmost layer that may indicate that it has shifted to the left. This is often a mechanical issue but could be the result of a (possibly more than one) nozzle crash which resulted in the machine losing it's position on the X axis. Your bottom photo definitely shows artifacts which could cause a nozzle crash and such a loss of position. The top photo also shows what may be some layer shifts on the bottom.
Hopefully some folks reading this who are more familiar with the Mini can add to this.
I know this would be frustrating, since it's a large and time-consuming (and filament-consuming) print.
You might try scaling this down to 1/3 or 1/2 for testing, and trying the full size only when you are confident that the issues are resolved.
Sorry I did not have a magic bullet for you here.
RE: Failed ABS print of a large circle with a lip... fails when making the lip
@jsw
Very helpful advice, and amazing insight you collected from my photos. Yes, there was artifact on the perimeter which did cause one of the prints to crash w/ nozzle and shift the print (thus the ghosting). I ran out of my ABS filament so I am back to PLA. I'll attempt again w/ no draft shield to see how it prints. If it prints well then I think all my issues were do to heating/cooling
RE: Failed ABS print of a large circle with a lip... fails when making the lip
Printed with PLA. There seems to be artifact, possible overextrusion, where the base and lip meet, but overall a decent print. Guess my issue was a heating/cooling issue with ABS.
RE: Failed ABS print of a large circle with a lip... fails when making the lip
ABS has the reputation of being tricky to print, but I've had good luck simply by observing a few things.
I've found that using the draft shield helps quite a bit with the occasional ABS print drooping. I've gotten into the habit of using it on all but the thinnest ABS prints.
I always let the printer preheat to ABS temperatures and stabilize maybe 10 minutes or so once it's reached temperature.
I also wait for things to cool down before removing the print. Let the print become more dimensionally stable before stressing it with the removal.
RE: Failed ABS print of a large circle with a lip... fails when making the lip
Do you have it in an enclosure? Does it break loose from the PEI plate? Have you tried ASA? That has worked for me, but for things to not warp, I do the following:
I use an enclosure vented to the outside with just enough fan so I don't smell Styrene.
I usually use a draft shield.
I scrupulously clean the print bed with IPA before printing so it will stick.
I wait till it is cool to remove it.
I clean the print bed with Acetone to get off any remnants of ASA.
Note that overhangs and bridges don't turn out well at all, lots of zits. I generally cut parts in two so there are two flat sides on the print bed and glue them together.
Regards,
Mark