I redid the Carbide Create files with my own numbers, which I got from G-Wizard, and made four different designs. They came out pretty great! They spin forever, and people love them. Here's a fun video:
The insert nut doesn't really work for this, and in fact it will unscrew itself sometimes. I'm going to switch to a small lock nut. I think you'd need a thicker piece of material to really get the benefit of the insert nut, and you'd need to mill a hole for it on the other side, which makes it a two sided job. Probably not worth the trouble.
I do think the protruding hardware on these ornaments is the least pleasing part. I may make some nicer ones out of wood and brass, in which case I will find ways to hide the screws and nuts.
The hole I milled for the screw to go in was too small. A very trivial fix, but a bit surprising, since the hole in the CC file seems correct. I am going to test my machine for runout.
Overall a very fun project! Impressed some relatives who don't understand what a CNC machine is useful for, and I love having the ornaments. Thanks for posting it, @ApolloCrowe
Here's my CC files, if anyone wants to use them. I did the bottoms and tops separately:
xmas_orns_2016.zip (638.3 KB)