Question about Servo Wires

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SavouryBromine

Joined Jul 1, 2023
19
Quick question: In a robotic arm I am making, the servo motors with the highest torque will be 40 kg-cm (these: https://www.amazon.nl/-/en/dp/B0C64NLF1Q) with a current draw of ≈ 4-5 amps. Every other servo draws less current than this. Would standard 22 AWG servo wires (like these https://www.amazon.nl/-/en/dp/B08728B6HB) be suitable for connecting the servo to power and to the microcontroller (Arduino Mega), or is there another type of wiring/connection method I can use that is better? I know I cannot loosely attach wires to the servo due to complications caused by EMI, but I'm not really sure about how else I could optimize wiring and what type of wires to use to connect the servos to power and PWM. Note that I will be using a power distribution board (https://www.amazon.nl/-/en/dp/B0814B5P5M) to deliver power to each individual servo, of which there will be 7.
 

Ya’akov

Joined Jan 27, 2019
8,954
22AWG wire in copper (and you may not be getting copper depending on where you buy it) has a maximum ampacity of 5A, so it is not suitable for 5A servos.

I don’t like those distribution boards because those terminals are notoriously unreliable. At least use ferrules on the wires. You will need to figure out the maximum current that will be drawn at any one time and make sure the wiring has at least 20% more ampacity than that, preferably 25%.

I would also strongly recommend using silicone insulated wire. It is very easy to strip, it doesn’t melt back when you solder to it, and it will handle the heat if something goes wrong without melting and shorting.
 

Ya’akov

Joined Jan 27, 2019
8,954
Before I acquired a ferrule tool ($$$). I used to solder the wire tips to eliminate stray wire ends on those type terminals. ;)
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Tinning is better than not—sometimes. but it depends on the connector type and the wire itself. If you have topcoat wire you can get away without any solder and it won’t have the vulnerability to break-off where the tinned wire meets the bare wire.

One of the biggest problems is cheap and/or poorly designed terminals. The difference between genuine rising clamp types and various cheaper alternatives is massive. I would almost be inclined to simply use DIN mount terminals, and cases for the entire project. Especially a robot where mechanical stresses and vibrations are going to be an enemy.
 
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