Trapped Outside

photo 1
 
Designed by: glyphobet   contact | Shop: Glyphobet
1.5 w x 1.5 d x 1.5 h in cm |

This is a model of Boy's Surface, a one-sided surface with no edges and no pinch points.

In the cutaway images you can see a small ball. It can roll in three directions but is trapped in the space cut out by the single-sided surface.

The ball is visible through a single cut that winds around the surface.

Note: The ball is red for clarity in the screenshots only. The entire model will be the same color when printed.

Other versions:

Without the ball: http://www.shapeways.com/model/237518/trapped_outside__track_.html

Solid, hollow inside: http://www.shapeways.com/model/233704/trapped_outside__solid_with_hole_.html

Solid: http://www.shapeways.com/model/233703/trapped_outside__solid_.html

Remember to give this model five stars if you like it!

© 2009, Matt Chisholm. All rights reserved.

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@erichschlaikjer: I heard back from Shapeways; they can't print moving parts in metal, that's why this can't be printed. Here's a version that has no moving parts: http://www.shapeways.com/model/233704/trapped_outside__solid_with_hole_.html
Wed Apr 6 16:27:21 2011 by glyphobet
Well, first I ordered it in basic plastic, but since that was way below the minimum spend I splashed out on Gold Plated Glossy, which at the time was quoted at $70.45. I thought it might go nicely with my glass klein bottle xmas ornaments.
Fri Apr 1 20:02:19 2011 by erichschlaikjer
@erichschlaikjer: Not sure what went wrong with your order. I've emailed Shapeways tech support to try to figure it out for you. Do you remember what specific metal material you ordered?
Fri Apr 1 18:16:25 2011 by glyphobet
My order was canceled because they can't print the ball. Perhaps this was because I tried to print it in metal, but they didn't say.
Fri Apr 1 13:04:34 2011 by erichschlaikjer
Sounds like you received the old version. Could you post a picture of the model you got?
Mon Aug 30 07:54:19 2010 by glyphobet
Just a week ago or so, the end of July. Weird.
Thu Aug 5 14:23:58 2010 by clsn
Interesting, I updated it to the version with the slit in February 2010. When did you order your model?
Thu Aug 5 02:38:07 2010 by glyphobet
Mine didn't have a slit along the surface, as described... but I think I like it better that way! Can still see the ball at the ends of its "tunnel"
Wed Aug 4 20:50:04 2010 by clsn
Read more about the mathematics of Boy's Surface here: http://en.wikipedia.org/wiki/Boy%27s_surface

Construct a paper model here: http://www.math.uic.edu/~fields/topology/Boys_surface.html

See some nifty videos here: http://www.geom.uiuc.edu/zoo/toptype/pplane/boy/
Sun Jul 19 21:56:40 2009 by glyphobet
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