The type of servos I used are called Standard Servos. These are able to rotate a maximum of about 175 degrees and provide more than enough range of motion for this project.
To anchor the servos, you will need a surface stronger than the felt material that the prop is made out of. The holes you will create are for the servo spline.
For the sake of simplicity, I simply eye-balled the location for where the hole should go and started drilling. For better-looking results, you may want to do some measuring first.
This should hold the servo onto the cardboard. The servo spline may not poke all the way through the cardboard but that’s ok because the servo horn should still be able to connect to the spline.
Remember to take into account the servos angle of motion so that you get the maximum range of motion for your project. Spend some time making sure it can perform the motion you want before anchoring the servo down permanently. You will likely need to loosen or remove the horn again to apply glue.
Each servo horn is too short to move a limb on its own. You can use popsicle sticks, pipe cleaners, or other makeshift items and glue them onto the servo horn so that the servo can reach further. I didn’t have popsicle sticks unfortunately, because somebody decided to eat ALL of the popsicles in the freezer here at Parallax.
There are no hard and fast rules to the arts and crafts part of this project. I used aluminum parts from one of our crawler kits but you can also use any type of item that you think will do the job.