Chain-Wrapped Housing for SoulCage

Vishalsoniindia (@electrodonut on YouTube) created the awesome SoulCage - The Digital Trapped Soul Pendant, and he got it featured on Hackaday.  I thought I could make it even better by replacing the rather generic housing with one that has spikes, is wrapped in chains, and has ominous lettering on the back.  So here it is.

N.B. I am working on improved firmware for the SoulCage too.  If/when I release it,  I'll update this post.

UPDATE Oct. 13, 2025: I've published the alternate firmware.  You can find it here.

All glory to Vishal, though.  It's his idea.  I'm just refining it.

I modeled this in Fusion 360.  I've included the CAD model in .f3d and .STEP formats.

Printing

You can just print the single color version.  It's optimized for 0.2mm layer height.

Or you can spice it up as shown in the photos.  What I did:

• red-black dual color PLA (PolyMaker Panchroma Dual Matte Shadow Red PLA)
• bright red PLA for the lettering on the back
• matte black PLA for the spike insets
• Ironing for the spike insets
• fuzzy skin on the outer perimeter
• 5 perimeters on the battery clip for strength
• set “bridging angle” to 45° so lettering has consistent grain

You'll also need a length of printed Easy Chain.  100 links should be a good length, or print 150 links to be sure.

And print a couple of Easy Chain Magnetic Clasps.

I've included a .3mf file with all the features listed, plus 150 links of Easy Chain and two magnetic clasps, on three print beds.

Assembly

Follow Vishal's tutorial on Instructables, but substitute this case.  After it's assembled, thread the easy chain through the spikes' holes.  The top spikes have room for two chains.  You can see in the photos how I looped the chain through.

Last, attach the magnetic clasps at a good length and snip off any excess chain.