16 Replies Latest reply on Jun 18, 2014 5:49 PM by Jerry Steiger

    Lunar Globe Project - Need help putting together a 3D model of the moon

    Christopher Camp

      Hello,

       

       

      I'm kind of shooting in the dark here, but I've started this project and I feel compelled to see it through. I'm working on a project to create a cast aluminum globe of the moon, something on the order of 21-24 centimeters in size, that uses data from the LRO to create a highly accurate reproduction. This would be a kickstarter project similar to the 3D lunar map (http://www.wired.com/2012/02/3d-moon-map/).

       

       

      I've had conversations with a number of metal fabrication companies and they've requested a 3D model (sldprt, igs or stp preferred) of the moon in order to send a price quote - this is a critical element for moving the project forward. I've had conversations with a number of people at JPL and NASA and they've been very supportive, but I need help getting the existing data (see links below) into a file type that the metal fab companies can work with.

       

       

      I'm willing to pay a reasonable amount for someone or a team to help make this happen. Please let me know if you have any ideas on how to move this forward, how long you think it would take and what you think it would cost.

       

       

      Thank you,

      Chris

       

       

      Data Sets

      http://wms.lroc.asu.edu/lroc/view_rdr/WAC_GLD100 (64 ppd should be fine) - this is the leading candidate in terms of datasets, but this is not my area of expertise so I need someone to help figure out what the best starting point is.

      http://wms.lroc.asu.edu/lroc/rdr_product_select - home of the LROC data sets

      http://imbrium.mit.edu/LOLA.html

      http://planetologia.elte.hu/ipcd/ipcd.html?cim=virtual_moon_soviet

      https://3dwarehouse.sketchup.com/model.html?id=8dfb3b57ce5b32506a12484fa9d9be10

      Potentially useful related info - http://selena.sai.msu.ru/Rod/Publications/Rodionova%20ICC2013.pdf

        • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
          Dheeraj S

          Hello Christopher,

           

          A very interesting project indeed!

          I am not too sure of how one has to go about doing this, but I sure would like to buy one if its put up on sale!

           

          If someone can take of converting the image into data points I am willing to work on the 3D model.

           

          Is your facrication process as following:

          1. Create a Rapid Prototyped part of the moon.
          2. Use it as a mold to create a die.
          3. Cast Aluminum in the die.

           


          • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
            Joe Kuzich

            Is this just as a for fun kind of thing or does it need to be accurate? 

             

            In order to even see them I think you'd have to exaggerate the heck out of the crater sizes or at least only focus on the largest.  That's such a small model I wonder if you could wrap the face of a sphere with the maps and have it laser etched. 

             

            You could manually model the whole moon as close to full scale as possible and then just shrink it down.  Sounds like a lot of effort.  Though I doubt you'd have to be very accurate since the moons face is constantly changing anyway, at least with the smaller craters.

            It seams like a very fun idea but a pretty big task at the same time.  Good luck, please keep us posted how you progress with it.

            • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
              Chris Dordoni

              Hi Chris,

               

              I also responded to you over on Renderosity (site Mail).

               

              You were asked for a nurbs model (sldprt, igs, stp) by the metal fabrication companies presumably because they intend to CNC mill a mold. Basically, they won't talk to you until you have a model in that format. However, none of the data for the lunar surface will be in nurbs format. It can be converted, but that will be an additional expense.


              It may be possible to 3d print a model (no nurbs or milling required) and use it as a master in some type of casting.

               

              The first step in any machining or molding process would be to construct a polygonal model based on the data.

               

              If it turns out you must have a nurbs model, that would have to be converted from the polygonal model.

               

              At the size you indicate, the height of the surface detail will have to be exaggerated quite a bit in order for it to show up, so that might require a bit of testing on small sections to find out what the best vertical scale multiplier would be for the intended diameter.

               

              I would like to discuss this with you.

                • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
                  Christopher Camp

                  Hi Chris,

                   

                  Thanks for the response. The metal fab company I've been talking with recently is planning to do a 3D printed model and then make silicone molds from that. They'll then do a lost wax casting.

                   

                  The general thinking of everyone involved, especially the JPL and NASA folks I've been talking with, is to do something as accurate as possible. The original idea was to use the new altimiter datat from the Luner Reconnaissance Orbiter to make the most accurate model of the moon ever produced. And unless that's simply infeasible that's the direction I'd like to continue working in.

                   

                  that said, I've run some of the numbers in terms of scale and I do have some concerns that the features of the moon will not show up well on a ~9" globe. There are more than 1 million craters on the moon, 11,000+ are larger than 20km in size, but even a 20km crater will be less than 0.5mm on a 24cm moon. So the resolution would either have to be very high (I'm not sure if 0.1mm is sufficient but I'm also not sure how much more detailed we could go because I don't know what level of detail a high-end 3D printer can faithfully render) or the size of the moon would need to be increased.

                   

                  I've reached out the metal fab team on these points and they're going to get back to me. That said, here are the estimates they've given me so far:

                   

                  - $4,000 for the initial physical 3D model

                  - $1,500 for the original silicone mold (which will do a run of 10-50 moons) and $700 for each subsequent mold

                  - and a unit cost of $275 for each 9" aluminum moon if we do a run of 100 or more.

                   

                  So about $350 a unit (run of 100), not including the cost of getting the 3D CAD drawing done. I approached them about doing a 14 or 16" version and they gave me a ballpark quote of $600-700 for the 14" version. $750 per moon starts to be expensive enough that I'm not sure we could sell 50 or 100 units via a kickstarter.

                   

                  I appreciate any input that you might have on all this. I think it would be a great object to produce and there is nothing like it on the market right now.

                   

                  Thanks,

                  Chris


                • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
                  Kelef Man

                  hei'ya Chris, lurv the sound of the project

                  and on the positive side- it's not Jupiter

                  on the practical side to get a minds picture,

                  as stated earlier, the moon is quite flat and

                  the scale is approx.- 1:15,000,000 I think-

                  this puts the deepest feature (South Pole Crater? 13.5km) at 0.9mm-ish

                  and the highest mountain(? 5.5km) standing 0.36mm-ish proud

                  and a feature limit of 0.1mm

                  would render  1.5km> differances invisible,

                  and the nurbs will only reduce the other features- too

                  but hey. love it, and I would be happy to contribute if I can

                  - go dude, have a good'n kelef

                    • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
                      Christopher Camp

                      Hi Kelef,

                       

                      Thanks for helping to think this through.

                       

                      There's nothing quite as inspiring as the sight of Mons Huygens at 0.36mm!

                       

                      Even if we scale it up to 16" / 40cm, that still yeilds a height of 0.575mm. I have real concerns that this kind of detail can't be faithfully rendered by even the highest end 3D printers. But I'm no expert and it seems like it's worth printing a sample or two at various scales to see what we get.

                       

                      And, we could always exaggerate the features, maybe 2-3x? I didn't want to go there, but it may be better to do that than to end the project.

                       

                      -Chris

                      • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
                        Jerry Steiger

                        Kelef and Chris,

                         

                        The good news is that the vertical resolution of the Objet 3D printers is much finer than the horizontal resolution. On the one that we just bought, they claim 600 dpi horizontal and 1600 dpi vertical. That gives you 0.016 mm steps vertically. If you're right about the 1/15,000,000 scale, you would have 240 m steps vertically. Your horizontal resolution would be 635 m. You probably couldn't resolve features finer than a km or two or three in diameter.

                         

                        The bad news is that you will have to build your model up out of sectors to keep the vertical more or less vertical, but you would probably have to make it in sections anyway.

                         

                        The next question is how would you get the light and dark coloring on your cast model?

                         

                        Jerry S.

                      • Re: Lunar Globe Project - Need help putting together a 3D model of the moon
                        Annette Jennings

                        Coming at this from a different perspective - could earth-globe makers' techniques enlighten the process?