what is the best solution for many IO?

Hello, I am doing a project and I want the user to be able to connect about 12X3 wires (12 wires, each wire has 3 internal wires)
in each wire there are 3 wires, red white and black when all the whites should but shorted and all the blacks should be shorted,

What is the best way for me to connect it? I have a friend with a 3D printer so I thought about making an arduino box which will have the terminals (with screws) in them and then connect it to the arduino board (my own PCB) with some sort of cable, the cable should be able to transfer up to 0.5A for short bursts (100mS).

any suggestions?

thanks.

The thing you want is called a "bus bar".