I'm trying to find a good mast for lighted signals and trying to balance practicality and realism. I've 3D printed designed my own signal system, the mast is the only thing that you must use some type of third party tubing. The obvious choice is brass tubing. With a 1.2mm tube I can cram 2 wires down it(tight) and solder and use the mast itself as the ground. This works for two LEDs but won't if you want to go 4, with two signal heads on ether sides of the mast. 1.5mm gives me three wires with the mast as the ground. Then we start to go to 2mm tubing and the realism of the mast size starts to not look so good. I looked into swizzle straws for coffee. They would be great as the wall thickness on these is thin and leave plenty of room. but the diameter is still to big. Looking for other ideas.