Engineers/Architects, I need help on making a half sphere
Hey basilmarket, I need some advice on how to create a half-sphere for my project. I am trying to create a model of the atomic bomb, and I'm doing it mostly out of paper foam board. I've completed a cylinder body for the bomb, but I'm getting stuck on how to create the head of the bomb, which is more or less a half sphere, out of foam board. I've tried to just find styrofoam balls and cut them in half, but none of them have a big enough diameter to match the diameter of the cylinder, and it would be very tedious to reconstruct the whole body to a smaller size. What I'm trying to do now to make the half sphere is to try to do it how a beach ball is made. If you look at a beach ball, it has what looks like ellipse segments all joining up to create the whole sphere, but I'm having trouble doing this as well. (I don't know what exactly the curves look like, and can't find a deflated beach ball anywhere to look at) Could anyone give me any more ideas on how to make this half sphere out of foam board or any other cheap material? (I don't think paper mache would work though)
4 Comments • Newest first
[quote=wackyiraqi][url=http://hyperexperience.com/wp-content/uploads/2007/10/sphere-unfolded.jpg]hi[/url][/quote]
Oh boy... That would like it would be a pain to do on foam board. Thanks for the idea though, might have to try it if I can't figure something out...
[quote=SouIStrike]I had to make a hot air balloon for lab once (in a group). We wanted to make it look like a sphere so we tried the same beach ball approach, but with only 4 strips it didnt look spherical at all . Also, it was too heavy to float lol.
I would think something like this [url=http://virtualmathmuseum.org/Surface/sphere/sphere.png]link[/url] but with less vertical strips. Cut vertical oval strips first, then partially cut the foam board along the long side so that you shape them? And if you cut too much, tape the pieces from inside.[/quote]
Hm, yeah I just tested making one with 4 strips with just paper, and there were a bunch of openings. Isn't the picture of the sphere pretty much the same thing as the beach ball method though? Just with more strips? Also, I'm having some trouble understanding what exactly the strips look like, because I can't find a 2D picture. Are they just a bunch of ellipses that are the EXACT same shape and size just connected together? do you know?
You could use a balloon, newspaper and glue
but it would take you at least 24 hours
I had to make a hot air balloon for lab once (in a group). We wanted to make it look like a sphere so we tried the same beach ball approach, but with only 4 strips it didnt look spherical at all . Also, it was too heavy to float lol.
I would think something like this [url=http://virtualmathmuseum.org/Surface/sphere/sphere.png]link[/url] but with less vertical strips. Cut vertical oval strips first, then partially cut the foam board along the long side so that you shape them? And if you cut too much, tape the pieces from inside.
[quote=wackyiraqi][url=http://hyperexperience.com/wp-content/uploads/2007/10/sphere-unfolded.jpg]hi[/url][/quote]
welp, good luck to you TS.