The gimble mount required some modification as shown in the image below. The primary problem was that the nut at the bottom of the gimble would come loose. Once that happens the tab on the gimble shaft that makes the skull pan left/right comes loose. Then it doesn’t matter if your servo is working, the skull will no longer turn left/right.
If you tighten the nut down so the tab stays in place, you can push the nylon cap nut where the other 2 servos attach off the top of the rod. It will strip the threads out and push it off the top.
The fix was to remove the regular 1/4-20 nut at the bottom and replace it with a nylon lock nut. I then added a new nut to the top so that I have metal pushing against metal. See the picture for details. The side effect is that the extra depth of the nut pushes the tab down a little. So to get your servo arm back in proper alignment you have to let the arm out a little more. If your little piece of all-thread is to short, you may not be able to get the servo attachment arm back into perfect alignment.
Here is a picture of the controller board. The black and red wires on the left side are to the 9 Volt Battery Clip. The 2 black wires directly below that are to the 5 Volt plug in power supply. The connector of the power supply has been cut off, and wire striped back to fit into the connectors on the board. The top wire has a white stripe along the side that is not visible in the picture. Click on the image to see the full size with the annotations.
This domain has been hanging around for a while now so may as well do something useful with it. I will be documenting a few halloween projects here. The first is the latest Make & Take project from CalHauntsNorCal. This a truly demented group that gets together once a month and does something “Halloween-y”. Projects in the past have included pneumatic ground breaker zombies, corpsing a skeleton, make-up and silicone mold making demonstrations, lifecasting, monster mud reapers, and lots more.
The current project is a 3-Axis articulating skull. The skull will be able to turn, tilt, and nod. And there is a 4th servo to operate the jaw. The build is complicated with the servos and servo connections, electrical connections, software, and programming. I am going to try and document my efforts so that others in the group can benefit from my triumphs and mistakes.