3D design software seems to be making progress in the open-source world, but it's still in its infancy (maybe toddlerhood). The picture was generated by freeCAD, which is good enough to make illustrations with, but it would drive me up the wall to try to make production models.
There are various DIY 3D printer initiatives out there, but I don't know which, if any, are worth spit.
I have both Solidworks and Cubify Design (when I bought it, it was called Alibre Design) programs so I have been able to compare them. Both are parametric modellers capable of making large assemblies of individual parts. Parametric means that if you are working in an assembly and a part doesn't fit, you can edit the part in the assembly and the program updates the info in all the part and drawing files for that part throughout the whole project. This feature really saves time and errors.
Cubify also has a program called Cubify Invent for 49 bucks. This program is a dumbed down Cubify Design. It can only build part models but looks very useful if you only want to make individual parts. This software is aimed directly at the 3D printer market and looks like a good deal.
Building your own printer is a complete hobby in itself, which means that you really have to want to spend a lot of time working out all the bugs etc.
What printer do you have, brand/model ?
I have a Afinia H480 which is a re-branded Chinese machine sold and service out of the USA. When I bought it, it was the only machine that had a 1 year guarantee but now other firms are also offering this protection. This machine is super easy and simple to set up and operate... and virtually prints out-of-the-box.
I've been thinking about 3D printers a lot lately. I wonder about the feasibility of scanning an apc prop, reversing the image and printing a plug to mold my own left hand props from.
This is theoretically possible but I'm not sure that it would be practical at this level of technology. I don't know how good the low-cost 3D scanners are because I haven't had any experience with them. I know that the high-end scanners can do a good job and it is easy (with the software) to mirror the model. These printers also have problems making thin features that come to a sharp edge... like a prop blade.
If successful,the printed prop however would still need to be worked to smooth the surface before I would use it for a plug. I routinely make plugs for canopies this way but I have to sand and fill the surface of the model to get the finish I need.
Orv.