RETIRED Spherical Wind Spinner

###RETIRED
I'm retiring this because, generally, it doesn't spin well. It looks great and if you get the right wind, it spins like a demon - for a few seconds. I'm working on a new one that will spin well and hopefully look at least a little like this. So, have fun downloading and printing it if you want something that looks great and maybe spins a little when it feels like it. I'll update this thing with a link to the new one once I've published it.

###Not to be Sold
I'm sharing my files so that you can make them for yourselves or give them away as gifts. I hope you enjoy them. I do not authorize sale of my work by anyone. Please don't ask me.

###Summary
This spinner is based on my Festive Spiral Christmas Ornaments.

https://youtu.be/NTR0JH1OtKQ

UPDATE 1:

The new version is the same width, but taller, each blade is wider at the outside edge, the top and bottom are wider and simpler, and the blades are more vertical. The new design looks better and seems to catch the wind better. It hasn't been very windy since I finished it, so I'm not sure how much better. Surprisingly, it's also a bit harder to print, but if you succeed, it prints more cleanly.

UPDATE 2:

By popular demand, I've created a version for dual-head printers. I don't have one myself, so I don't know how well it will work. If you try it, please let me know.

UPDATE 3:

I've added versions of design 2 (single and dual head) with sacrificial bridges at the suggestion of @Varazir. The bridges reduce or eliminate the need for automatically generated supports in the center of the model. I ran some tests printing the top 1.5cm and found that with just the inner edges of the blades to adhere to, the bridge layer prints better with small tube supports between the blades. 3mm was enough, but would be likely to break off during printing. Increasing to 6mm diameter didn't improve printing, but it made the supports much more substantial. You might need to make them 8-10mm to make them strong enough to go all the way to the top without breaking loose. Even with these custom supports, using the sacrificial bridge versions will reduce print time and material. It will also make it a lot easier to remove the supports. Still, it adds clean-up at the end. I recommend running tests like I did to determine which method you want to use. It will depend a lot on your printer.

Update 4:

I've added my latest design with enhancements suggested by @Varazir (throw away layer on top hole) and @RICK8340 (small counter-rotating blades) that together completely eliminate the need for supports. I've also gone back to a spherical design with larger blades. This seems to work a lot better and still looks great.

I found that Sky Shark P400 carbon fiber rods work well for the center shaft. They are available from a lot of vendors. You may need to adjust the size of the support and bracket slightly (0.5 - 1%) depending on your printer.