Finally, today, I drilled and tapped the holes that will hold the lexan plates I made the other day in place in the skulls.
I found that the easiest way to get it lined up right was to drill holes where I wanted them in the skull first, then line up the lexan inside the skull and mark off where the holes come through.
I didn't even measure. I made the holes about a half inch below the top of the skull and put one near the seam on each side. You can see the seam where the skull is put together if you look close. The holes look like this:
Just remember that the plate fits in at an angle. The back is near the top and the front get's screwed down to the inside of the skull.
Here is the lexan placed in the skull after the holes were drilled in the skull:
Then, with a silver sharpie, I marked the spots where the holes come through the skull:
Then with the spots marked, I put the plate in the vise and drilled a small hole (Which I will later tap for a 4-40 screw) in the edge of the lexan:
Then, as I mentioned, I tapped the hole with a tap made for 4-40 screws, since that is what I will be using to hold the plates in:
If you look close, you can see the hole in the edge of the lexan in this picture:
Next, I will mount all the servos on the new plates, but I can't screw them into the skulls until I finish all the central rods and mount them to the rod ends in the skulls.
I also still need to make the aluminum strips that hold the jaw servos in place.
I'll document that another day.
For the Jaw servo, I did use a different armature. I wanted a longer one, so I used a two part armature that came in the package with the servo. It includes a small square section that mounts right on the servo, then a long adjustable arm slides into that first piece. I set it all the way out. It looks like this:
I will not be using the linkage pieces I got from ServoCity.com for this servo. The jaw is moved by a piece of thin wire that I fit through the outermost hole in the armature. It then goes through a hole I drill in the skull and attaches to another hole I drill in the jaw. You can also see in that picture that I am going to cut off one side of the servo mounting brackets. I am doing this because this servo stands up on end. It needs to be flat on what will now be the bottom as it will be held in place with the aluminum strap I will be making.
I could have cut a slot in the lexan for these mounting brackets to fit in. That would have been a better idea, but I didn't think of it until I was done with the lexan plates. It would not be easy to do that as an afterthought. So it was easier to chop off the brackets. After I cut them off, I filed the remaining stubs off like so:
One of these days, I'm going to spend that nickel!