Two screws more
  • May I suggest two mechanical customization?
    The intermediate wheel arbor is the only arbor not easily removable, and I had to unscrew the whole frame for a check of this component. This could be boring, so to prevent this next time, I drilled the rear frame, from the front side, and screwed a short grub screw M5 from the back side. I think it's a good solution, for setting the axial backlash and access to the whole clock. I didn't use a threading tap, just push and screwed in plywood, very easy.
    The clutch on the minute arbor can be or become too loose on the arbor, so I added a "tangent" screw, between the two holes of the clutch, that I can screw or unscrew, adjusting the friction of the minute hand.
  • I used grub screws too when making Tertious, after bolting frames together i drilled from back to give perfect allingment for arbours and sealed back with grub screws which as you say helps setting backlash. I learnt the hard way after building my first clock and getting master plans mixed up with photocopies i made which turned out to be 5% smaller so one frame was bigger than the other and holes didnt want to meet.