We revisited this project this year to dispense high fat diet over a 24 hour cycle, and decided to make the design more reliable.  Where we used to just push the pellet disk onto the clock mechanism and hope friction held it together, we now are using the brass threaded nut to hold everything together securely.  We are also printing the disk in two parts, with an internal hexoganol cog that can get clamped down onto the clock movement.  STLs in the files area, here are some photos of the new parts:

And two of them assembled, these were set up with the high fat diet (blue stuff) in the first compartment and left overnight.  After 24 hours they dropped it out of the dispensing gap.