[FTC]: Possibility of encoder mounts on regular axles

Hello, I’m a part of an FTC team in Virginia. As a part of our design, we have a joint powered by a single continuous rotation servo. In order to more accurately move it, we were wondering if it would be possible to mount a DC motor encoder in some way onto a standard, approximately 3/16" inch axle connected to the aforementioned axle.

Has anyone tried anything similar or have any ideas on the matter?