30x30 test cube with a 1.2mm volcano

Appreciate this seems like a crazy long time ago now, but since I acquired a second BB, I have the ability to play with the volcano without having to continually dismantle in order to get back to a working standard nozzle. Also having the hotend able to be changed relatively quickly also helps there. Anyway, here's my box in opposite corners printed with a volcano, essentially as a tool to maximise retraction issues.









I used a retraction length of 4mm and had configured a 1.25mm extra retraction length to attempt to counter what seemed to be a move-length-related restart issue; i.e. that the longer the move length seems to be, the poorer the quality of the restart. You can't see that fully here because the poor quality restart is masked due to having two perimeters; the poor quality restart is on the inner perimeter.

Using Duet I was able to increase the retraction parameters on the fly, starting at the bottom with 0mm restart and terrible performance after the massive move, all the way to 1.5mm on about layer 7, then adjusting down to 1.25mm for the final layer. There are 3 solid base layers and 4 solid top layers, which just create one honeycomb layer which is enough to create problems that require 4 layers to fix. The main issue is that, while 1.25 extra restart seems good for the massive move for the inner perimeter, it's too much for the short move for the subsequent outer perimeter.

I found this topic while search for inspiration for alternative figures to try, so thought I'd post.

I have found that the primary melt zone in the e3d v6 standard nozzle seems to be 6mm and recommendations from e3D suggest a maximum retraction of 5mm for that nozzle. In practice I've only ever used about 1.5mm. 1.5mm definitely leads to significant oozing with a volcano. The volcano primary melt zone seems to be 14.5mm, so I'm wondering what I could go up to.