I am working on a quadwalker, I am desigining it to be invertable, but that is a ways off, here is the image of the parts attached and wired. It uses TowerPro MG90S servos on a PLA plastic frame.
All the parts were designed in OpenSCAD and 3D printed. Here are the scad files for anyone interested. However these are simply version 1 plans and I planned to make a few changes for v2 (based on my 3d printers behavior mostly).
My next plan is to get a UBEC for powering the servo hat and back charging the battery for the Pi Zero W used for control. Then I was going to test each servo for basic movement and design some controls.
Eventually I plan to use my FrSky X8R to control it once I get it self contained (I will be using the wifi connection for testing/debugging purposes however). Maybe use an accelerometer to determine which way is down so it can climb small slopes or to know if it knocked into something.