Mini Quadruped - optimized for 9G servos

thingiverse

Droger's adaptation of Andromeda's quadruped design is impressive! They've saved time for many DIY enthusiasts who were planning their own designs. However, the original design didn't fit some cheap 9G micro servos. To resolve this issue, someone optimized the design to suit these commonly available servos. The OpenSCAD files for the parts have been zipped up for easy access and can be tweaked to fit your specific servos or printer tolerances. The picture shown is of mid-prototype parts; the final designs feature rounded corners and other improvements. Recently, the OpenSCAD files in the zip package were cleaned up, making them parametric so that users can adjust a few dimensions to get parts that will fit their servos perfectly. These files now also support different servo horn dimensions. A beta version of the design intended for Tower Pro blue servos is available, though it's essential to note that there are no guarantees without actual testing due to pending servo arrivals. The design includes 4 leg parts, 2 hip parts, 1 backbone part, 8 shoulder parts, and 8 servo buttons. The servo buttons fit into the hole in the shoulder opposite the servo horn, acting as a bearing for the servo's movement. In case of printer issues with these small parts, you may use clipped-up bits from unused servo horns. The shoulder junction is designed to be held together by two 3mm x 6mm screw/nut each, diagonally offset from different directions. The code for the movement was derived from lumi's "chopstick jr" on Let's Make Robots. An update includes a partially completed Arduino code for forward movements. For those interested in electronics and wiring, an Eagle schematic and board file are available. Instructions for soldering female pin headers to accept the Arduino Nano on a small perf board and connecting three rows of pin headers for power have been provided. The project uses four 1.2v rechargeable AA batteries for power, wired directly to the 5v rail of the Arduino. The Ultrasonic Module HC-SR04 Distance Sensor is used for the eyes and is wired to D13 (TRIG) and D3 (ECHO). Users can choose alternative pins, but remember to adjust the code accordingly.