I've gotten to see the inside of a lot of ventriloquist figure heads, and seen a lot of interesting mechanics. And from some of the feedback I've gotten, mechanics is one of the things a lot of people are interested in when it comes to figure making.
I was looking through some of my archived photos here, and a couple photos I had to stop and look at again, thinking about how there is always more than one way to do the same thing. Here's the inside of one of the figures I was looking at....
As I recall, this is a Ray Guyll head, a reproduction of a vintage figure. What I was particularly focusing on in this case were the pulleys or the way the cord for the winkers and such are handled. In this figure the cords go up over styrene tubes which rotate over brass rods. I've use this method myself on some of the figures I've built, and it can work quite nicely.
The advantage to that style is the tubing is easy to find (local hobby store), easy to cut and install, and does not require a cord containment set up like regular pulleys usually do. Speaking of which, as a comparison, here's a pic inside one of my heads with regular pulleys.....
Regular pulleys can be more challenging to install as you have to have them fairly well aligned or else the cords will rub and make noise against the pulleys. And you should have some type of cord containment over the pulleys (copper wire in the photos above), lest the cords jump off of the pulley at some point.
The second biggest challenge with this style is finding some suitable small pulleys. I figured out how to cast my own several years back, so I could have the exact right size pulleys with the diameter of pivot hole I prefer.
Another way to handle the actuation of winkers is with a rocker or lever (like a teeter totter) as shown in the photo below (the gray metal objects). . . .
That's a Rick Price head that has fancy cast rockers, similar to what Chuck Jackson did. The rocker method typically works better with cord controlled eyes. If you look at the photos with the regular pulleys above, that head has rod controlled eyes. The cords coming down off of the back end of the rockers will likely interfere with the movement of the rod control for the eyes.
This is one of the biggest lessons I've learned with figure making over the years: Anytime you try a new animation or a different version of an animation you've done before, you have to make sure that this new animation is compatible with the other existing mechanics inside the head. Sometimes a very small change can create an interesting or challenging situation.
I have done rockers, and I have done a combination of rockers and pulleys in some of the heads I have made (like pulleys for the winkers and a rocker for the raising eyebrows). As you play with these different styles, you will find advantages and disadvantages to each method.
In any case, this is just one example of several ways to do the same thing. And the above methods are surely not the only way to actuate winkers. If you ever get a chance to look inside some Selberg heads, you will see some different methods yet.
I enjoy studying and developing new ways of doing mechanics inside dummy heads. But mechanics are only one aspect of figure making. What other aspects are particularly of interest to you? Would love to hear from you.