Reply To: Ratchet mechanism for opening slit in dome

[Roy Hughes]

First thought.
You have a square toothed wheel at the end of the shaft.
How about a simple arm with a matching tooth.
Pivoted above the wheel, lift to disengage, lower to lock.
Would need a spring in-line with the pivot to hold it open/closed
Not as nice as an auto ratchet but very easy to make.
Roy