I just finished making the additional 3 Plexi-Glass inserts that you mount the servos to.
I actually made them out of 1/4 inch Lexan.
Here are two of the finished products (I have 4 all together now):
Making these was easy because I was able to use the right tools!
My neighbor with the machine shop has a drill press with a CNC X-Y table under it, so the square holes were cut with a router bit in the drill press, and I adjusted the table which was holding the lexan from side to side and up and forward and back the cuts.
This picture is one I found on the net of a similar machine. I didn't take a pic of my freinds press.
Anyway, I used the drill press to cut the square holes and to make all the holes for the screws that I later tapped with a 440 thread tap bit.
I cut out the main outer shape with a bandsaw and then filed the edges with a buffing wheel.
The large center hole was cut with a bit similar to a doorknob hole cutter, just smaller.
I have an actual size template that you can download and print out. I used this template to cut all the pieces of Lexan.
First, I sprayed some 3M spray adhesive on the back of the paper template, then stuck it to the protective paper coating on the lexan. Once it dried, I cut a rectangle out of the lexan around the glued paper template making sure that the outside edges were parallel with the square hole cuts I needed to make for the servos.
So I had a rectangle shaped piece of lexan that had a piece of paper glued to it with my template design printed on it.
Here is the template:
Right Click on the above link and select "Save Target As" from the right Click Menu. Print the file using the windows Picture and Fax Viewer full page to get the correct size.
There are ruler marks on the left edge of the image. If they are one inch apart, then you have printed it to scale.
Here is what I mean by the edges being parallel to the square holes:
Then I was able to put the lexan into the CNC table and cut the square holes easily with the drill press. If they weren't parallel, I would have to make constant adjustments and would not have been able to make straight edges.
Here is what the plate looks like with a servo through one of the holes:
And finally here is how the plate fits into the skull:
The back end of the plate is mounted right at the top edge of the skull with two screws which go through the skull and into the edge of the lexan. The front is screwed down to the inside base of the skull between the eyes using the single hole at the very bottom of the template. It rests in the skull at an angle on purpose. When the lexan plate is parallel to the ground surface, the skull is lifted up slightly and seems to be looking straight ahead instead of looking down. This provides a "Center" spot with range of motion in both up and down directions.
This template is made specifically to fit the "Pirate Skull" by lindberg. It is a lightweight skull kit that can be found in many places such as this one:
I will post more pics and instructions when I finish making the custom rods I will be using that fit through the rod ends.
More to follow....