Just a simple 3 piece arm and mount for any webcam or any other small accessories (for example an LED light) that you might want to attach to 8mm threaded rod. Just change the "camera mount" to anything that fits 10mm diameter hole on the "Rod").
I printed the nut and bolt that would fit the 8mm threaded rod, (available here: http://www.thingiverse.com/thing:193647) so I did not use any other hardware. They work much better than I expected.
I am currently using it to hold a Logitech c910/c920 webcam without having to take apart it's factory stand (I could not find one that doesn't require the webcam original parts to be disassembled on Thingiverse).
The Design-Spark file is also attached so you can customize anything as you see fit for your purpose.