Hello for my hexapod project i’m going to use 12 DS3240 (40kg/cm) and 6 MG996R (13.6kg/cm) servos for in the legs. To power my hexapod i’m thinking of using a 4400mAh 3S 45C lipo battery and then a Hobbywing ubec 10A to convert the voltage to 6v for the built in screw terminals on the servo 2040. The hexapod will also feature a nema17 stepper motor and a cctv camera (both controlled by a RPi4).
I have measured with my powersupply that both the DS3240 and MG996R have a current draw of 3A when stalling which makes me wonder if the servo 2040 can handle it. Am i confusing peak current draw of the servos with the allowed maximum 10A continous current of the screw terminals stated on the website.
Also can anyone recommend a good (XT60) PDB to which i could connect my lipo to distribute power to the entire system?
Hey,
As the maths suggests, 18 servos drawing 3A stall current each would be 54A total. In practice you are unlikely to reach even a quarter of this (unless you intentionally program your hexapod to have all its servos hit their end stops). So having a 10A UBEC would likely cover your needs. If there are occasional peaks above 10A then the UBEC should act as a limiter. I notice we don’t list a peak current for the screw terminal of Servo 2040, but the board itself is not designed for distributing much more than 10A.
If you have doubt about the current capability, I would suggest you look into our Yukon board. Pimoroni Yukon . It has a LiPo battery connector directly on it (we sell a XT60 to XT30 adapter cable too), and has modules for driving servos that feature their own regulators removing the need for a 6V UBEC. Quad Servo Module for Yukon (There’s a version without regulation if you can spec your input battery voltage to the servos). It could also function as your stepper motor driver Dual Motor / Bipolar Stepper Module for Yukon
As for PDB, not really, but if you did use a Yukon then all you’d need is a XT60 Y-splitter to get power to it and to whatever regulator you use for your Pi.