So, there are options for designing parts and having them printed that don't require your own equipment. There are a few CAD programs out there that are reasonably easy to use and completely free (one is even open source).
Google/Trimble/some other company Sketchup (likely the easiest)
Autodesk 123D Design
OpenSCAD (open source)
They're all free, available at least on Windows (also mac and linux for some) and not *terribly* hard to use.
So, you can design your part there, and then there are companies who will print your parts for you. You typically send what's called an stl file, which is basically your part broken up into triangles (they're also used for video games). Then the company prints it out on their machines. They're not cheap, but you can get really good detail on stuff.
The one notable example is Shapeways (shapeways.com), they've been doing this for a looong time. Also, there's a company called Ponoko (ponoko.com) who traditionally did stuff with laser cutters, but is also breaking out into the 3d printing space.
If I were to make more shoulder pads, without any of the resources I have access to, I would design my parts in sketchup, and have them printed at Shapeways. They have different 3d printers capable of printing at different resolutions in different materials, so you have lots of options. For 40k scale stuff, you're probably going to want the "Frosted Ultra Detail" which is the equivalent of what I used for my shoulder pads.
Anyway, if you have more questions, feel free to PM me or some such.
