The idea is to control every servo with one of the two axis of a ps2-like joystick. (if some of you might need some real instructions, just ask in the comments, and I’ll do my best to create a step-by-step guide) List of materials: - Structure - M5x7cm screw x5, m5 bolts x15 (base) - M3x16mm screw x18* - M3x20mm screw x13* - M3 bolts x40* - M3x8cm screw x3 - Clamp (otherwise it will fall) - 3 dowels - Arduino (or something else to control it, it has to have at least 5 PWM) - Something to supply 5-6V and at least 1.5A - 3x ps2-like joysticks - 4x TowerPro mg995 servos - 1x TowerPro 9g microservo (for the grip) - Lots of jumper wires - Breadboard *(I used bolts and screws to be able to assemble and disassemble quickly, otherwise you could replace almost all of them with woodworks screws)
So I salvaged a charger (6V 1.5A) and soldered two jumper wires to it. Power supply: The Arduino was definitely not enough for the servos, since each mg995 draws 350mA and the microservo 9g draws 100mA, for a total of 350*4 +100 = 1500mA.
I could have also bought different servos, with decreasing torque while moving away from the base, but buying identical servos from the same vendor was by far the cheapest option. Well, this gives me some safety and the chance to load up to 2kg of load (which is impossible, but I like that I could technically do it). Apparently 6 kg/cm would have been enough for the 2nd servo (from the base), and mine provides 9-11 kg/cm. I calculated the required torque with the rule of thumb, later on I tried a more accurate calculation and I found out that I might have overkilled it a little. Then I had to buy the electronics: Most of the parts were standard, the hard part was to choose the servos. I had to build it a few times, each one of them I found something wrong, and we had to recut some pieces and retry. Since I didn’t want to copy and paste the project from someone else, I took a project as reference and I (and a couple of more skilled classmates who really saved me) started to modify it according to our needs (different servos with different torque, weight and dimensions, etc.). First I needed a structure: This was definitely the longest part.
0 kommentar(er)
