Steve, in your assembly instructions for the large crazy gear clock, gear 3b-15 appears in two different places, once on page 51 and once on page 52. Since there is only one gear 3b-15 I'm guessing this is an error?
Yes, there was a typo. It is supposed to look like this:
The assembly guides have become so complex that a few errors often remain even after proofreading several times. Thanks for providing feedback.
The assembly guide at SP10/11 Crazy Gear Desk Clock | Steve's Clocks (stevesclocks.com) has the most updated information including this fix. Two new diagrams were added on pages 51 and 52 that might also help with assembly.