Neat picture. One day I am going to have fun and get to do that to my K20D
There is some flexible and one or two solid PCB boards in dSLRs. However in and around the mirror-box is an incredible amount of moving parts. Moreover they need great precession in manufacture and lose that precession during use, so they need tune-ups. To be honest this design was for film. When you could not shoot 1000 pics a day or put about 20,000 pics a year on a dSLR as I do.. Something has to be better for digital. Not saying mirror less, something even more advanced.
And yes I would bet the K-5 or K-7 use plastic gears even though they are premium. The K10D and K20D were the top premium models a few years ago
Now with the push to smaller and lighter...
EDIT I had to see how Nikon makes em, to my surprise the D300 is by just looking at it superior in materials. It uses metal gears. I am a 100% Pentax fanboy, believe me I am. But this is not good IMO... I have to post a link as the author is retaining rights to the pics but have a look... Believe me I know car engines use plastic in gears but in a failure that stresses the gear they are usually the first thing to break. Like timing chain upper gears that are metal and have plastic teeth...
Nikon D300 Mirror Box | Flickr - Photo Sharing!
Not only does Nikon use metal in the D300 its brass or copper and stainless steel for corrosion resistance... If the D7000 is made like this its enough to make me...