Linkage for Linear Motion from Servo.
This was originally going to be a question on mechanical advantage and tinsnips but I've realised the answer during typing the question. So, my follow-up question is . . .
I'm looking to extend the throw of a servo and convert this to a roughly linear motion but still keep the whole mechanism compact. I'd like around a 4 to1 gearing (with corresponding loss of force, of course). Is there a simple linkage I should be looking at to get this?