I have an arm, similar to the vex example arm. It is mounted on a seperate wheel base, and the arm has motors on it that need to connect to a microcontroller independent from the turntable. Is there any wiring trick I can do for the motors on the turntable’s arm that would allow me to turn as much as i want (360° clockwise, 720° clockwise, etc) without tangling the wires and as a result pulling them from the microcontroller?
you can always put the wires through the center, but even then you will have a finite limit of rotation.
How Aperture got around this problem with wires is literally put the microcontroller and every system needed to power the HOG on the turret.
- Andrew
Thanks for answering.
Sorry, what do you mean by HOG? Also, are you saying that your solution allowed for unlimited rotation of the turret on top of an external drive train? Did mounting your microcontroller this way have any complications?
What he means is that he mounted the electronics on the turntable. This means no matter how much you rotate the turntable, the relative positions of the microcontroller and the arm will be the same = no tangling wires.
There’s no way to run wires with VEX parts to allow for unlimited rotation in the way you describe. You can have longer wires to allow for a larger range (720 degrees for example), but the wires will become twisted. If the wires go through the middle, they will still get twisted, but it may be neater than running the wires on the outside.
If you do mount the microcontroller on the arm, you will need separate controllers for the drive base.
The only way to transfer power through the turntable and allow for unlimited rotation is to run an axle through the middle, like you see on swivel drives.
HOG = Hand of God
Its one Aperture Robotics robot, we have no drive train so this allows us to mount everything onto one system and not have to worry about tangling of wires like SweetMochi said. However running the wires through the center for you would probably work very well as long as you dont go super crazy on turns like 10000 degrees or something like that.
but 720 it should be perfectly fine as long as you put the wires in the center of the turn table.
- Andrew
There is a solution to this that nobody is talking about…
Everyone says that it is impossible, but for college teams, it is highly possible.
- Strip some wire down, and put it in multiple circles, each one slightly smaller than the previous one.
- Run the wire from the ground side up, and attach it to these circles of wire. (for PWM cables, you’ll need 3 circles inside one-another. then, just split the PWM cable up…)
- On the rotating side, split a PWM cable open, and at each of the three ends, put a brush or some sort of contact, and attach this to the turret.
Solution: You should have something that will maintain a connection no matter how many times you turn it… I’m pretty sure it wouldn’t be legal for High School, but hey, in college, you are allowed to modify electronics. 
But then again, there are a few ideas that I have for High School where you could make a limitless rotation system that’s VEX legal…
I think that you are only allowed to modify electronics for sensors in college. I don’t think the solution that you are talking about is legal.
Normally, this is the case, but, check the link below. The rules were changed so that college teams could modify pretty much all the electronics except for the Cortex and VEXNET…
https://vexforum.com/t/answered-custom-electronics-for-college/18994/1
I remember seeing that a while back, but I never connected it to modifying the motors. Thanks. Now that I know, “Sweet!”. This opens up designs that are usually not possible due to the very restraints that the OP is talking about (only for college teams of course).
I was going to mention the ring option with the wires, but because it’s not legal for High School, it seemed unneccesary to mention.
And getting that to work (holding the wires in the right place) is pretty difficult.
I would think slip rings would pretty hard to build reliably. If you can modify the electronics, including cables, I think using a coiled multi-core cable (perhaps the partner joystick cable) and allowing a limited number of rotations would be better. Use a power expander above the joint to reduce the current, you then need +5V, GND, and one pwm signal per motor, 4 motor control on a 6 wire cable (assuming cross talk is not an issue). Or better still, use a signal splitter and mux the pwm for 6 motors onto one wire.