# Does anyone have a pattern for cutting a flat surface and shaping it into a sphere (or hemispere)?

I'd like to make a sheet metal ball, maybe two inches in diameter. I've seen on "how they make it" (or some show) that they die cut paper for globes and then form the cut paper over a cardboard hemisphere. The paper is die cut in a pattern so that the cut pieces come together to form the hemisphere with no creasing or folding. I've googled with no answers (at least that I could find). Thank you! Steve

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SabihaK1 year ago
PaulM401 year ago
paucoma2 years ago

I know this is old, but I'm adding my comments for whoever may stumble across this later.

I made an instructable which makes an approximation to creating a dome.

Perhaps may be good enough:

https://www.instructables.com/id/Calculate-and-draw...

While searching I also found some elipsoidal parachute design:

http://www.nakka-rocketry.net/paracon.html#Design

And here another design guide:

http://www.kiteplans.org/planos/hemisphere/hemisph...

Cheers,

joemed4 years ago
If you have photoshop - here is an awesome filter that makes multiple different gores for sphere cut outs. It also creates fish eye and a long list of other cool effects.
http://www.flamingpear.com/flexify.html
There is a try before you buy and you can test the effect.

enjoy
joe
apriluk7 years ago

Hi There, Do you mean something like this? It should be easy to calculate the sizes you want from this sort of squashed globe map template using maths explained web site to get the right formulae etc, Also an image like this would be relatively easy to cut out in sheet metal as it doesnt have too many fiddly bits, I have resized the image above when I copied it into this advert and probably lost the correct proportions but I searched on world globe map etc to get this image, looks as though you could probably break it down further into 12 identical pieces if you wanted, and I bet the maths tutorials sites would walk you through the size calculations if you are as hopeless at maths as I am. Hope thia helps,
mikeasaurus8 years ago
Another option would be to find a ball approximately the same diameter that you desire and cut it open adding notches until it's flat. Reverse engineering. From there you'll have your pattern. Hope this helps!
Scubabubba8 years ago
Here's a discussion on how to lay out your own gores. It won't be perfect because you're trying to make a compound curvature surface out of a ruled surface.

Dr. Math

http://mathforum.org/library/drmath/view/55168.html

poolgirlblue8 years ago
look into a program called Pepakura
8bit8 years ago
Perhaps you could do research into globe projections.