I did a little measuring of the 216 centreboard mechanism today and determined that the cable eye that attached to the end of the ram moves about 12” as you raise/lower the board.
The fully retracted ram (centreboard raised) is about 22” long. This would be the available space for all the pulleys to work in.
It’s my understanding that the 216 board is about 500lbs and the 212 board is 150lbs. The 212 board is longer however and I don’t know where the attachment and rotation points are for it.
The centreboard system on the 212 is pretty complex but I think the mechanical advantage of all the pulleys is 9 or 10 if you didn’t use the one labeled 5 in the diagram and just connected the cable eye to the becket of the 4 block labeled 7.
I’m not sure of the math but I think that would make the 500lbs “feel” like 50lbs.
If that’s accurate it sounds feasible to use this kind of setup to replace the Sailtec unit.
Mount a couple of double blocks at the aft end of the slot, make some kind of slider car that would allow the 4 block to move back and forth without jamming in the slot and you have a viable alternative to the ram.
@JimInPB Can you comment on how much effort is required to move the board on the 212?