After a truly terrible week of meatspace problems last week, I'm back.
I've been working on and off on a 3D printed case for the cluster. The case doesn't need to be beautiful, but it does need to protect the cluster and restrain the Zeros so they don't flop around on the backplane's USB headers.
One problem though: the HPL runs from earlier show that the CPUs can reach over 70 degrees under load in ambient air. In an enclosure it's going to be much higher even with vents for convective airflow, and PLA plastic starts getting soft around 65 degrees...
Thus a fan is going into the case somehow.
Enjoy this pic of a test fit print while I figure this out: