Based on https://www.printables.com/model/227155-nf-crazy-volcano-sock-mold from Karnadi, which I found didnt fit my hotend very well, I went ahead and designed something a little bit thinner, and with extra focus on gripping the top of the hotend.
Excludes the original air gaps in order to make molding with RTV a little easier as it's more viscous than casting silicones.
Required hardware:
6 M3 nuts (Locking or non-locking)
4 M3x35 (as few as 2) bolts → Can be longer
2 M3x25 bolts → Can be longer
The author remixed this model.