It’s been a bit of a battle, but I think I finally have the turntable lock control finished. The original plan called for a flexible shaft to drive the pin into the sockets around the turntable edge. However, when push came to shove (so to speak), I found that the shaft had to flex too much, and the action was not reliable. Moreover, this placed the knob below the handle that turns the turntable, which I didn’t feel was intuitive.
So, I devised a contraption that involved a hinge, a longish piece of aluminum and some 10-24 threaded rod. It’s a bit of a Rube Goldberg machine, but seems to work with a satisfying thunk. This puts the knob to the left of the handle, which I hope makes it clear that you should pull the knob before attempting to turn the handle.
A few construction notes for my fellow bodgers (or me in the future):
- I made a new locking pin by turning down some of the threaded rod. This made a solid connection, compared to the previous version, which was brass tube and the flexible shaft.
- It was important to support the threaded rods with brass tubes for as much of their length as I could. Otherwise, they tended to bend, rather than shift.
- The shape of that piece of aluminum was determined solely by trial and error. It slips against the benchwork in the corner, and I may decide to add a little wear plate if I find it is needed.