Hi there, I'm looking for a specific type of fastener of which I don't know actually exists. I'm hoping someone here will be able to point me in a direction or give other advice. In the simplest terms, I'm attempting to mount a rod and mass such that it can rotate on an encoder shaft. However, I don't what would be the best/most lightweight method for doing this. Referring to the image (here - http://imgur.com/6YBB4S2), i'm hoping that there exists a device that has a hole with set screw such that it can be fastened to the rod. And then I also wish for this device to have a thread hole such that the rod can be fastened to it. Refer to the assembly in the lower part of the diagram. Does such a device exist? Are there easier methods for doing this? I'm looking for a light weight solution. Thanks!