I get emails from Vendors all the time about their technologies. Keyence sent me this just today and made me think of this thread:
https://www.keyence.com/mykeyence/?ptn=001
Or in the attached PDF.
Knowing Keyence, this solution is probably $10k/piece and they won't let you even borrow an evaluation unit to test and see if it will work for the application. And they won't offer you any other value added services like terminating/labeling cables or even minor component assemblies... I've dealt with them before
RE: Old_Phart
Yes, you are right that the ultrasonic is probably not the best solution for this considering the beam dispersion. They make super precise pinpoint type (SICK), but they tend be very expensive and have extremely limited range. I like your idea about the vision system though.
RE: jbvries
You should look up how people use the XBOX kinect system to 3D image items and reverse engineer them. There's a hugely popular thread on here where a guy hacked the xbox kinect, used it to image an 18" tall Iron Man figurine, scaled the model to life-sized and then milled it out on his mill out of foam. He then painted it and put it in a display case. The thing was awesome. I imagine the kinect would be accurate enough for what you intend to do.