First up, its always good to do a bit of planning.

I went directly to the kerbal space program site for reference pictures (theres a very limited amount of pictures of the actual kerbals around, maybe 2-3 pictures in total on the site) The little Kerbal sitting on the preorder/donate button and the 3 in the banner up the top were pretty much all I had to work with, but it was enough.



The next thing I needed to think about was the size of the model, relative to how much I wanted to spend for this project. To work that out, I needed to have information about the material(s) to print the final model in.

(Page with details for all the materials at shapeways - http://www.shapeways.com/materials)

Since I didnt want to paint the models once they were printed (or any additional post-production work for that matter) I decided that the 'Full Colour Sandstone' was a good option. Its an easy choice to make, since theres no other material at this stage which prints full colour models.



For the visor things are a bit trickier, and it took a few test prints before I found the right material. I wanted something transparent (preferably plastic) so the visor is see-though enough to see the Kerbals face behind it.

I ended up choosing the 'Transparent Detail' material, its not perfect, but its the best material Shapeways had to offer for this.



Full Colour Sandstone (FCS) material page for more info - http://www.shapeways.com/materials/fullcolor

Transparent Detail (TD) material page for more info - http://www.shapeways.com/materials/white_detail



So now with the details of the material(s) known, I worked on determining how big to make the model, without having to sell off limbs and cars/houses to fund the project (3D printing *can* be very expensive, if your not careful)



Note - another important thing these material details provide us with, is the 'detail tolerance' of the material. This is important, because it lets us know what level of detail the material can be printed in - ie theres no point modeling in details down to 1mm, if the material only had details down to 4mm printable, this additional detail wont turn up in the final print and will be a waste of time and effort.

Its also important to know if the model will print correctly, ie if you have a tiny tube or wire, or thin part of the character mesh, it might print so thin that the material breaks during transport, or deforms in a way you dont want as its being printed.



To make things even more complicated, it could be worth looking into printing a 'hollow' model, to save on materials and bring the price down, but this is something I didnt do for this particular project, as the models were small enough already, and making them hollow would be troublesome and in the end not worth the effort.



So with all of this in mind, I determined that the models should aim to stand at around 3 inches tall (while wearing the helmet), this would allow for the level of detail needed, and not be too expensive.