Looking for a vector file of a globe in flat pattern

[Dougr]

I am looking for a vector file of a globe that I need to build. The file should look like this. I will cut out the pattern from steel with a CNC plasma cutting table and wrap it around a framework. Does anyone have a file like this or can you direct me in the right direction? Almost any vector file will work however I mostly us DXF. or CorelDrawX6.

[natcase701]

This powerpoint by Daan Strebe (one of the top experts on map projections) has some very brief summaries of criteria in choosing a globe gore projection and rendering: http://mapthematics.com/Downloads/Gores.pdf

This also may be useful:http://www.progonos.com/furuti/MapPr...t/projInt.html

I would suggest working with Natural Earth's dataset (http://naturalearthdata.com), and render each gore separately. I can do this in AvenzaMaPublisher (resulting in a PDF, AI, or EPS file, or possibly DXF) if you don't find someone else, pretty inexpensively. Basically you want to choose how many gores you want to use, divide up the the earth into sections, evaluate how much if any overlap you want between gores, and then render each section with a polyconic projection.

I did a project with someone using a laser cutter to cut wood or steel with recently, and the problem we had was that the cutter had a diameter to it that ended up wrecking key bits of coastal detail. We ended up with a solution that involved expanding the coastline by half the diameter of the cutting tool, which worked OK. The client got all upset when I told him I needed to charge him real money for the third or fourth hand-corrected rendering. Very odd. Anyway, I'm happy to talk about this with you. You can contact me at http://incasellc.com/nat/contact-nat-case/

[Hai-Etlik]

It sounds like you might be better off doing projections on a contiguous landmass basis rather than regular gores. It's more work to figure out, but less in terms of fabrication as it reduces the number of parts and seams between them.

[johnvanvliet]

for the Earth

your final output needs to be a SVG

for a black and white image that is somewhat easy

start with the STRM or GTPO30 or the Gmted 2010 data

for the GMTED 2010 is not the full planet
i have a reworked full 90 north to 90 south here
Ds15.zip-- 855 Meg
https://drive.google.com/open?id=0B6...YVU&authuser=0

use sealevel for the black and white save as a ppm image ( netppm)
and use netppm's "ppmglobe" to make the gores

ppmglobe 6 InputImage.ppm > OutputImage.ppm

and you get


then a bit trace in inkscape to output a SVG

the strm is here
http://dds.cr.usgs.gov/srtm/version2_1/

a bit easier to use the nasa Bluemarble topo data
http://mirrors.arsc.edu/nasa/topography/

small 5400x2700 jpg preview image
http://mirrors.arsc.edu/nasa/topogra....5400x2700.jpg


this water mask is ALREADY black and white only -- might work
-- small preview
http://mirrors.arsc.edu/nasa/landmas....5400x2700.png
http://mirrors.arsc.edu/nasa/landmask/


How big is this globe ?
1 Meter diameter ?
10 Meters diameter ?
20 Meters diameter ?

or something table top size like 30 CM ?


natcase701 has a good point
the cutter OD dia. !!!!

just like in casting the model has to be made with a "shrinkage " ruler

the width of the plasma cut will NEED to be accounted for

Do you have access to Autocad ( very pricy - used car pricy)

[Dougr]

Thanks for the all the replies. This globe is going to be 2.5 meters in diameter. The company doing the welding will is building a metal frame work with 12 ribs. I will be cutting the land objects and they will weld them to the frame.
I think I want to use this map as a starting point.
http://mirrors.arsc.edu/nasa/landmas...k.5400x2700.pn
But how does that work if I just cut it into gores. What happens if I loose critical details. Does that not change the shape of some of the land masses?

The plasma cutter kerf is not a problem. I have software that take a vector file and offsets the cut line by half the width of the kerf. Also a have an AutoCad type CAD program. How would that make this project simpler?

Doug

[johnvanvliet]

for a globe with a diameter of 2.5 M is a circumference of 7.85 Meters
a base image like the one above with a size of 5400x2700 pixels is 687.89 px/M or 6.8789 pixels per CM
might be a bit too low resolution ??? maybe


netppm
http://netpbm.sourceforge.net/
should be installed by default on every linux and apple computer and maybe on windows ( postcstipt can use it in printing )
remapping it into 12 Gores ( or 24 )
-- convert the png ( portable network graphics ) to a ppm ( portable pixel map )

ppmglobe -background=gray 12 world.oceanmask.5400x2700.ppm > 12.ppm

for a black background remove "-background=gray" from the command
-- small downsize

from there inkscape
https://inkscape.org/en/
can convert it to a SVG

autocad also should be able to import a png or a bitmaped image and save as a svg
or as a 3d mesh format say the white as one unit in mesh height higher that the black

blender can even do that and maybe even "Anam8or"

the above is the EASY part

converting that to one of the file formats that are needed for the cutter ?
the people that own the cutter should be able to do that
the above image would be basically the same as a blue-print

[Chick]

You know, I was thinking about this last night and how I would go about it.

For all the high-tech solutions you are looking at here, I'd start with about a half dozen of these

http://www.amazon.com/Learning-Resou...ds=child+globe

and a pair of scissors, and start cutting and flattening, to see just exactly what distorts, where you can cut, bend, and re-weld to preserve the important details, and figure out what shape pieces you need.