# Streptohedron



## trc65 (Nov 22, 2021)

Or more specifically a femisphere. Yah. Yah. I know, or rather I don't, so don't ask me to define or describe either term.

Saw a reference to a femisphere while I was looking around for some ideas to make for kids gifts. Found an article and took a few minutes to make a prototype just to judge difficulty/time and to see if it would be any fun to make or play with. 

Didnt spend a lot of time on fitting or sanding, but think I'll go ahead and make a few of these for Christmas.









BTW, the article also recommended the book "Woodturning Full Circle" by David Springett for more examples of streptohedrons. I should have the book tomorrow...

Reactions: Like 6 | Way Cool 6 | Creative 1


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## ripjack13 (Nov 22, 2021)

Ok. So I just spent over an hour watching some video demos and looking this thing up.
Dude....that is so cool. I need to try it soon.
Nice job Tim.

Reactions: Thank You! 1


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## trc65 (Nov 22, 2021)

Thanks Marc.

Lot easier than it looks at first. I just glued it with CA to turn and then assemble, and used a little sanding drum in a Jacobs chuck to sand. Looking forward to getting the book and trying more "shapes"

Reactions: Like 1


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## 2feathers Creative Making (Nov 25, 2021)

Did you flip this before you turned it? To keep the grain aligned when it is reassembled.


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## trc65 (Nov 25, 2021)

No, didn't flip it. It was a piece of fairly straight trained maple, so just lucky. 

Got the book last night and got to admit it made my head hurt just skimming through it. Star-shaped streptohedrons, branch-streptohedrons, ribbon- streptohedrons, wave bowls and turning square holes......

About a dozen different projects detailed step by step, with endless variations for each. Great book, but it's going to take me a little while to digest everything.

Reactions: Like 2


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## JerseyHighlander (Nov 25, 2021)

Looks like one of those quantum physics representations of a three dimensional object projected into a 7th or 8th dimensional representation. Need to see a video of how that's turned.

Reactions: Like 1


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## trc65 (Nov 25, 2021)

I don't have anything to shoot a video, but I'll post link to an article and do a tutorial when I do a few more. These are deceptively easy, but you need to make patterns (simple ones) and be able to turn(near) mirror images or you'll have lots of sanding.

Reactions: Agree 1 | Informative 1


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## Nature Man (Nov 25, 2021)

Very unique! Hard to comprehend, but the instructions help! Chuck

Reactions: Like 1 | Agree 1


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## trc65 (Nov 25, 2021)

If I get time tomorrow, I'll make another and shoot some pictures. The instructions (to me) make it sound a little more complicated than it really is. I think I can simplify it greatly with a few pictures and shorter description.

Reactions: Useful 1


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## 2feathers Creative Making (Nov 26, 2021)

trc65 said:


> If I get time tomorrow, I'll make another and shoot some pictures. The instructions (to me) make it sound a little more complicated than it really is. I think I can simplify it greatly with a few pictures and shorter description.


Yeah, there should be a simple instruction for these simple yet unusual shapes. I haven't made one ( and really have no excuse) but they are simple concept after you close your eyes...

Reactions: Like 1


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## Jonkou (Nov 26, 2021)

Very cool precision turning Tim. Check out www.breezyhillturning.com for minimal surface work taken to the nth.

Reactions: Thank You! 1 | Way Cool 1


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## duncsuss (Nov 26, 2021)

JerseyHighlander said:


> Looks like one of those quantum physics representations of a three dimensional object projected into a 7th or 8th dimensional representation. Need to see a video of how that's turned.



Here's Captain Eddie Castelin's video on turning a femisphere/streptohedron/wotchamacallit ...

Reactions: Like 1 | Thank You! 1 | Useful 1


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## trc65 (Nov 26, 2021)

Jonkou said:


> Very cool precision turning Tim. Check out www.breezyhillturning.com for minimal surface work taken to the nth.


Thanks for the link! Incredible doesn't even start to describe his work. Seeing those types of projects is what inspired me to start looking for "simple" projects like the femisphere. Don't know how far I'll ever go in making "geometric" turnings, but I enjoy learning how they are done.

Reactions: Like 1


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## trc65 (Nov 26, 2021)

Posted a tutorial on this project.






Femisphere, a Type of Streptohedron


Just to get it out of the way..... The femisphere is a solid that has one single surface, two edges, and four vertices. And that's all I'm going to say about definitions! Here's what I'm talking about; It looks and sounds complicated, but really a simple, but precise, process. There is a...



woodbarter.com

Reactions: Like 1


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## trc65 (Nov 26, 2021)

duncsuss said:


> Here's Captain Eddie Castelin's video on turning a femisphere/streptohedron/wotchamacallit ...


Thanks for posting the vid! 

With that, the PDF I posted, and the tutorial I just linked everyone who wants should be able to make a few of these.


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## duncsuss (Nov 26, 2021)

Jonkou said:


> Very cool precision turning Tim. Check out www.breezyhillturning.com for minimal surface work taken to the nth.


Two or three years ago Michael Foster did a great demonstration at the NH Guild symposium (at Pinkerton Academy) - like many demonstrations, the big take-away I came home with was "I won't be doing that any time soon"

Reactions: Agree 1


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## ironman123 (Nov 27, 2021)

Those are neat.

Reactions: Thank You! 1


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