Mechanical Walking Robot Toy

thingiverse

I'm hooked on Robothuts walking toys, and I decided to create one myself. This pin walker design is a compact and straightforward project that utilizes a 6 Volt N20 gearmotor and two 2032 coin cells. The robot measures approximately 110 MM tall, 70 MM wide, and 40 MM deep (4.5" X 2.75" X 1.5"). I designed the battery holder to incorporate my own custom switch, made from a #1 paperclip. To ensure a good solder connection, choose a paperclip that can handle heat. A jig is provided for bending the contact into shape. This walking mechanism consists of pins in each leg driven up, down, back, and forth by a crank. Each leg requires a crank and pin. The cranks are 180 degrees apart to maintain synchronization. I attached a 3D printed 10-tooth gear to the gearmotor's output shaft, which drives another 10-tooth gear with a 3 MM or .125" brass shaft. The shaft features a crank on its opposite end, along with posts for driving the pins. These posts should be spaced approximately 180 degrees apart. I utilized a 6 Volt 100 RPM N20 gearmotor from Banggood, which runs quietly and has low current draw. Although coin cells are not ideal for powering motors, I prioritized compactness and simplicity. A small rechargeable lithium-ion cell like those used in quadcopters would fit nicely in the head, but I opted to avoid battery chargers, low-voltage cutoffs, and other complexities. I sourced my CR2032 cells from tea lights purchased on clearance at Wal Mart. These cells have performed well during testing, which has involved short bursts of 10-20 seconds adding up to several minutes. However, if you turn the robot on and let it walk for 30 seconds or more, the LEDs will start dimming or turning off due to voltage drop below their forward voltage when wired in series. To address this issue, I included a jig for soldering the LEDs and resistor into the head. The assembly sequence and details are showcased in a slide show at the end of the YouTube video linked below. YouTube Video: https://youtu.be/1caKmv_uRs0 3D Printed Parts: * Head_main * Head_base * Frame * Motor_clamp * Arm1 * Arm2 * Leg1 * Leg2 * Crank * D_gear * M_gear * Back_plate * Front_plate * Switch_jig * Led_jig * Switch1 * Switch2 Parts: * #1 paperclip * N20 6 Volt 100RPM gearmotor * 3 MM or .125" shaft, approximately 30 MM or 1.125" long * 2 LEDs * 1K resistor * 2 MM X 6 MM screw * 3 MM screws (6MM and 12MM) * 3 MM washers Update: I've added the Fusion 360 file. Thank you, Rick