Spherical chalkboard for teaching curvature - photo

[Jon]

Spherical chalkboard for teaching curvature.

Fullsize image: https://s3-us-west-1.amazonaws.com/h...e_fullsize.jpg




Previously:

Electronic touchscreen blackboard - GIF
Drawing a perfect circle on a chalkboard - GIF

[Frank S]

looks like he is doing the same thing I did to my 7 grade math teacher when I showed him my triangle had 3 right angles by drawing them on the globe

[IntheGroove]

Everyone knows the chalkboard, like the earth, is flat...

[owen moore]

The Flat Earth Society claims that they are the largest organization on the globe.

[DIYSwede]

Without getting into the Flat Earth discussion, and the consequences of the Earth thus having two surfaces:

-Anybody here considering DIYing a "Möbius Belt Sander":



or a "Klein SpilSure™ Coffee Mug":



(where the belt and mug above only have one surface)?

Perhaps giving the grandkids a "Studio Eluceo Ltd Mödel Railroad"?

[owen moore]

I actually built a mobius strip sanding belt for my Craftsman belt sander years ago. I glued two belts together back to back, gave the thing one twist and connected the ends. I tried it out and it worked fine. If you an idler wheel on the belt, it's imperative that the wheel remains in sync with the belts surface speed for obvious reasons. My sander is a 1" x 42". This allowed me a 1" x 84" belt surface.
I have often wondered why one of the abrasive belt makers haven't considered this as a new product. In industries where they use a lot of belt sanders, I would think it would be a great selling point to have twice the sanding surface.