Need advice on removing printing errors

I made a casket for my neighbor’s dwarf hamster last week. It turned out okay, but there were a few glitches in the print that I would like to resolve for future projects. I have attached images and the .ini file. The images are better to see if you click and expand them.

Thank you in advance,

woodbox.stl (2.72 KB)
gold.ini (12.6 KB)

The “random cracks” are due to Thermal Separation. When printing with ABS, temperature changes can cause portions of long thin walls to cool faster than the layers below them, causing the part to shrink down to its final size before the lower sections have cooled. This causes the upper plastic to contract and pull back from the lower levels. You can combat it by making the part thicker at the split point, building a temporary (turkey roasting bag taped over the printer) or permanent enclosure around the printer to keep the temperature warm. You can also try increasing the temperature of your hot end by 1 or 2 degrees to try for a better layer adhesion, though that can lead to other issues.

You also have a tiny bit of lifting at the base of part where it did not adhere to the print bed properly. Increase the heat bed temperature by about 3-6 degrees and see if that solves the issue.

The bottom layer ripple is a bit harder to tell what caused it. It’s probably due to a combination of starting layer height being too close, bed being out of level slightly too high on the two corners that match the edge of that part when it was on the bed, and possible slight overextrusion. check your fillament diameter in your Slic3r program and make sure it is set to what you actually measure on your fillament. Its easier to see what is going on there if you print just the first level, stop it there and then post a picture so we can see what is going on.

Okay, that makes sense. It is hot where I am, so our air conditioner has been running off and on all day, I wonder if that plays a part in the cracks. I don’t have a turkey bag big enough, but I’ll make something out of acrylic to surround the printer.

With respect to the ripple, I checked the filament diameter and it was set correctly. The bed might not be level because I recently replaced the base. I’ll verify it when I print the first layer. I don’t really understand 'over extrusion;, what value would create that? I would guess it would be either ‘Initial layer line width’, ‘bottom/top thickness’, ‘layer height’, or ‘filament flow’. It seems like these are all the same thing, but obviously not.

Thanks for your help.

here are the bed parameters

< Bed x: 0.00 y: 0.00 z: -0.48
< Bed x: 160.00 y: 0.00 z: -0.55
< Bed x: 160.00 y: 160.00 z: -0.42
< Bed x: 0.00 y: 160.00 z: -0.40
< Eqn coefficients: a: -0.00 b: 0.00 d: -0.49
< planeNormal x: 0.00 y: -0.00 z: 1.00

I agree with piercet’s diagnostic of the layer seperation. Increasing the extrusion temps by a few degrees will keep the plastic liquid/molten longer after leaving the hotend… which should help with adhesion to the adjacent layer.

In addition to increasing the temps, I also like to keep cooling from the fan fairly low 30-50%. Cooling ABS too fast can lead to contractions. Bridging is the only time I like to blip the fan to 100%… locking the filament in place.

The other thing to consider is the airflow from the fan, when it hits the edge of the project perimeter some of the air will deflect downwards along the wall. Thus further cooling the lower part of the project…

I don’t have much insight into problems with the lower side of the box. It could be one side lifting and causing the project to press against the nozzle. The PEI sticks to ABS pretty well and is very forgiving. Give the PEI bed a scrub with fine grit sandpaper (I’ve been using a Mr. Clean Magic Eraser which has very low grit, but removes oils). Do you remember if that side of the box was on the left / right side of the bed or front / back? That can help you determine extruder is uneven along X or Y axis. To truly diagnose, print a few 10x10mm or 20x20mm calibration cubes… or whatever length to help reproduce the issue.

Anyway, there’s a lot to consider, but you’ll find a sweet spot! Keep at it. :slight_smile:

I pulled the box off before I noticed the bottom, so I don’t remember which side it was on. I’ll try to reproduce it tomorrow. I had no idea that printing 3d stuff would be this complicated.

Now that I think of it, I only have these two issues when I am printing with ABS. I also print using PETG and haven’t noticed these problems.