This rbs is the regular sized one I had printed. (I tried scaling smaller from here). It's about 1-7/8 inches tall. The track separation is about 5/8 inches wide. It works fine. See the video.
This is a very small RBS. The ball was supposed to be attached to the top and to the side but the stick that attached it was so small it disappeared with printing. The rest of the sculpture arrived OK. I found the ball rolling around the bottom of the box. Hey, it works, though! Yea! See the video! http://www.youtube.com/watch?v=KGdUFg_X8mE
I think this is the smallest I can possibly make the Earring RBS given shapeways minimum wall thickness limitations for white strong and flexible. The frame is 1mm and the rails are 0.8 mm. Yes, I know 0.7 is real minimum but I don't want to risk it. Again, I haven't printed and tested it yet so I'm not sure if it works, but it should. It is very small at 1 inch wide by 2.25 inches tall. There is a loop at the top for hooking to an earring or it will also stand on its own. A very unique earring! Don't forget that if you want it for an earring you need to purchase two (one for each ear). You'll notice that this one is a little smaller than the earring rbs I uploaded previously. To play with it, you'll need to detach the attached 5 marbles.
http://www.youtube.com/watch?v=-as24TSv2-U
I revised the Christmas Ornament RBS to have just a little more slope. I'm hoping it's enough to have the marble roll without problem. I added a few new things. This one has a circular base so that it should stand on its own. I also beefed up the frame to make it more durable. There's less rungs and a few more braces. I will have to print it and test it. If you just want one even though it hasn't been tested, please feel free to order but you're on your own. http://www.rollingballsculpture.net
You can see video of it here: http://www.youtube.com/watch?v=qUlLRtTp050
I've attached a ball to the rolling ball sculpture with the idea that you cut it off and sand it and it should work as the marble. The marble is 5/8 inch so it should work with regular glass or wooden marbles too. Yea it works! See the video!
The design is for my daughter who has Cystic Fibrosis. The Roses in the Lungs represents the saying "65 Roses" which are sometimes easier for children to say than "Cystic Fibrosis". A friend of hers at school designed the artwork for her team fundraising T-Shirt for the CF Walk that we did in May and the Pendant is designed after that artwork with slight alterations to fit the Shapeways design rules. I'm hoping to give the pendant to my daughter for her birthday at the end of August. On the back of the shirt it says, "Believe in Bethany" which was our team name. We raised about $2500 during the walk which is the most we've every raised in the years we've been doing it. She is in College now. We are happy she has lived so long and she is doing so well. One day CF will mean Cure Found! http://www.zazzle.com/cystic_fibrosis_cf_lungs_and_roses_cure_found_tshirt-235802059256772046