Peter,
I love the idea of kinematic jewellery! It's great to see designs being manufactured.
You don't specify the problem with the arms. Are they too thin, could you beef them up a bit?
If you are getting separation between layers, it helps if you get the bed/chamber up to operating termperature before you start the build. Avoid cold rooms and anywhere there might be cold air/drafts.
The STL export from PTC Creo gives control over the mesh size. The attached instructions explain how to get a fine mesh.
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It might be possible to get your models made on a professional 3D printer, I'll email someone I know and copy you in.
I'm looking at how you assembled the parts in Creo and think there miight be a better way. I'll check it out and, if it works, I'll upload the result here.
Keep up the great work!
Tim