Large Mars Globe (75 cm diameter)

[Algebraist]

Dear all

After doing the north pole and then two rings it seemed just a matter of "plowing on".

So next came ring 3. Here it is being made and then complete



Then with the sellotape layer (pencil marked at the top of ease of overlapping next time) and then duck tape added



So here is what it looks like at this stage



It does not look very big, however it really is. Here is a roll of duck tape for scale



There are still two more rings to go to get to the equator and each ring "segment" is considerably larger than the previous ring. They are so big they are way bigger than my hand.

However for the next ring the real issue become the fact that this is a paper model of a "gore" globe design. Essentially (mathematically speaking) you have 3 choices in making a globe.

One: carve it from a 3d block of stuff
Two: Make it from lots of flat polygons joined (hinged)at the edges
Three: make it from "segments" (like an orange). The gores have curved sides and they join together along the curved edges

Here is the thing with option 3. Your material needs to be "continuously" deform-able in all directions simultaneously. You can prove mathematically, if your material is not (like paper) then you are going to have "issues" (wrinkles). The only question is how do you "spread out" the "excess paper?

It was ring 4 where this started to become visible. So to help "notching of parts help mask come of the excess. I found that two and 4 notches along the side was optimal, but as you can see there is still not perfect.



(If you try a big globe you will find that you can spread out the paper to get a good result I think)

Here is the ring finished and then that tape layers added



And the outside of the globe



Then the ring that takes you to the equator. It was a handful due to the size of the pieces and I found it a real challenge accurately gluing the parts in place. And it is really important to glue accurately on a globe (found out) as errors very quickly compound themselves. Just one mm out each time results in over a cm out around the globe! However it is manageable. Here is that ring



It is very unwieldy and wobbly at this stage. it is at its structural weakest too. However just managed to get a photo of this stage



Phew! Half way there.

Regards

Kevin

[THE DC]

This is looking great!

What an awesome project for educators, as well!

My compliments...

[gotham]

Templates downloaded, many thanks with link help.

[Algebraist]

Originally Posted by THE DC

This is looking great!

What an awesome project for educators, as well!

My compliments...

Thanks for the comments DC, much appreciated.

Regards

Kevin

[Algebraist]

Dear all

Now that the equator has been reached I found a slightly different "tab layout" for the next ring was best. The parts have the previous rings joining tabs AND the next ring joining tabs, so look like this



And here it is attached



The reason for the change is that now the globe starts to "close in on itself" and so when gluing the parts naturally lend themselves to having glue applied when the tabs are on the previous ring. It makes accurate joining way easier this way. Here is the ring completed and then sellotaped and then duck tapped



It really is taking up quite a bit if space if you do something like this I found resting on a bed good. You are constantly spinning the model so you need a bit area and "soft" so not as to damage the printing.

For the next ring (and subsequent rings) parts only have the "above" joining tabs, like this



And now attached to the globe



The size is becoming an issue now in terms of getting behind parts and firmly pressing the glued area (reach becoming difficult). I found a school type of "exercise book" was a good support. It was just about flexi and stiff enough to mould to the curved surface of the globe yet stiff enough to provide good support for pressing hard.

Here is the ring completed and then with the tapes added



The globe is now big compared to my arm as you can see from the photo. I am holding the camera with my other hand at full stretch to try and get everything in.



It can seem a bit unweildly at this point but I found by taking it steady and doing a "dry run" of each glue really helps.

Talking of big globes and control you might be interested in this. The first you tube is of some music that I "hear" when I see the second you tube clip (so maybe listen to the first clip whilst watching the second muted)





Now that is a bad day at the office for a globe maker!

Regards

Kevin

[Algebraist]

Originally Posted by Butelczynski

I found this Making globes of the planets

It might be of interest to someone.

Thanks for this . Some nice globes there.

Looking through the search option for the forum I see there is this thread

"Say, It's Only a Paper Moon..."

of which post 7 has three nice links to globes.

Regards

Kevin

[Algebraist]

Dear all

In terms of earth globes out of paper there are quite a lot out there. However some people may be interested in these earth polyhedral globes



They are designed by Carlos Furuti. However the site no loner has his pages. However you still can "just" get them through the wayback machine (though they seem to be disappearing even through that!)

I have just checked and to get to the page with all the downloadable printable polyhedral globes (of which the photo above is just a few) the link is

https://web.archive.org/web/20150623...t/foldout.html

Actually Carlos had a number of pages devoted to cartography which were excellent (of which the paper polyhedral globes was only a little "add on"). It is a really good read so here is a wayback link to the main page

https://web.archive.org/web/20150618...C/cartTOC.html

On this page you will see a topic called "Rebuilding the Earth into an exotic planet: polyhedral maps" and the last link in this topic (called "fold-outs for printing and assembling psudoglobes) takes you to the previously listed page of downloadable polyhedral globes.

IMO Carlos produced some of the finest earth polyhedral globes I have ever found on the internet. Unfortunately his pages no longer are current (at least I am unable to find any) and I have not had any response to trying to contact him over a number of years. I had hoped he might do some moon and planets polyhedral globes.

Hope this is interesting to people

Regards

Kevin

[rickstef]

Seeing that Carlos is a member here, and hopefully he will read this thread, he would be the best to update us all on the status of his site

[mbauer]

Originally Posted by Algebraist

Hi Mike

thanks for your comments. for a non techie like me how can I tell if something is in "vector" and can I convert things into vector if they are not?

Thanks

Kevin

Hi Kevin,

I've been printing a few large "wall" print jobs.

A friend wanted a specific photo printed as a 8ftx10 wall photo. Brought the photo into AutoCAD, scaled to the size he needed, then printed several 2ft wide x 8ft long strips of wall paper to complete the photo.

The wall paper is actually a polyester canvas that works as wall paper.

Scaling the photo to 8ftx10ft there was no pixilation. AutoCAD is a vector design program, not bitmap. There are a few other programs that are vector as well.

Normally a paint program is bitmap, while a drawing program is generally vector.

Inkscape is a freeware download.
"Inkscape: Inkscape is an open-source vector graphics editor similar to Adobe Illustrator, Corel Draw, Freehand, or Xara X. What sets Inkscape apart is its use of Scalable Vector Graphics (SVG), an open XML-based W3C standard, as the native format."

Open the vector based program, Inkscape for instance, and then using the file option you open the photo you want to work on. Not sure, but the secret I think is the word "scalable", in AutoCAD I just draw a box the size I want the actual photo to print at, then simply scale the side of the photo to the proper length. 8ft tall? Ok, just scale the photo with one of the vertical sides to 96".....The length went past 10ft, just centered in box, easy to choose what part of the photo to use for the wall paper project, how it works out.

Mike

[Algebraist]

Thanks for that Mike. Very helpful

Regards

Kevin