A few months ago I needed a calibration / stress test model. I whipped up this rather simple box that tests a few critical functions of a printer. In addition to basic X/Y/Z calibration, there are a couple features to exercise the cooling / bridging / overhang capabilities. The goal is simple, easy to validate and also comprehensive enough to catch the major print issues.
Nice calibration piece. Here is my result. Printed on an RB2. The high efficiency cooling duct can be seen in the background. missing/deleted image from Google+
Oh, and what was your layer height? It looks quite fine. 0.1mm? I should
adjust that - I think the red one was 0.15mm on a Printrbot #Frankenbot.
The blue one was 0.2mm on a Printrbot Simple - heavily modified for larger
print volume. Clearly based on your sample, I have a ways to go.
I’m running the version of Cura built into the latest Repetier-Host. The
GUI built into RH has limit view into Cura’s parameters.
Aside from obvious cooling issues with the printer, I observe some less
than ideal behaviour that is slicer based.
I would like the slicer to generally print perimeters first from the
outside to the inside. But, if path being printed would normally trigger a
support to be built, than print the perimeter from the inside to the
outside to improve adhesion to the existing print.
This one was at 0.1mm layer height. Since that is the layer height I print most often that is what I calibrate for.
So long as you are not turning a corner in free space there is always at least one edge or corner for your next segment to attach to. Typically I try to design objects with that in mind. Your piece is a good example of that design philosophy. Inner or outer first makes little difference but it would be nice to have the ability to switch as needed.
With that said check out this bridge and overhang piece I print to test the effectiveness of my cooling duct designs. If it can pass the 5 mm straight overhang (flat by layer 3-4) then it is a good design.