The Iris box is a test print that has a very small window for success in temp and retraction settings. Generally it brings great joy when you can print it at 1:1 scale and have it work smoothly.

Another option is the lattice cube. I know we already did these but maybe they should be the start to set a defined bar somewhere. And then we will go from there.

So here is a link to the lattice cube: Lattice Cube 3D Printer Torture Test (Overhangs and Dual-Extrusion) by Lazerlord - Thingiverse

I printed it with this rig: GEEETech i3 32bit Rework (3dprintboard.com)

These are the results I got with PETG filament using a 0.4mm nozzle..







I do not have further specs on the slicer for this print as it was a while back. But I am not against doing this again. It did not use a lot of filament. And that is the thing with these test prints Martin. We should try to find things that do not use a lot of filament because we understand we will likely toss our refuse when we are done with it. I personally do not mind printing larger things in the name of this thread just because the filaments from ebay are so damn cheap.

You can easily see how this lattice cube tests retraction settings. And printed right it looks cool, too. I can show you these pictures and you and CA can assess them tiny hairs and see if you can get it better. Or try to point out other flaws with the picture I am posting and if possible post it along with an honest suggestion about your ideas on how to resolve the issue you noticed. With tuning first if possible. Remember this is supposed to make us all better printers and make our robots more capable.

Try to print this or the iris box. Play with your settings and get it to print the best you can on your own. Then post up your results with as much detail about the final specs used and lets start discussing how each of us can up our game. Then you should find something with like a 1 layer wall thickness that is tall or something with reaching overhangs or something else to further test and tune our retraction settings with.

And I will print out the link you provided just because you posted it up here and to keep all this on a happy constructive note.