We used these on our intake:
https://www.mcmaster.com/#5234k92/=152mzbr
Once we mounted the rubber tubes on the aluminum inner tubes, we chucked it up in the lathe and took a super sharp razor blade to cut grooves. It worked fairly well for us, but in the future, we'll probably use slightly larger than the 1" aluminum tube because the rubber tube sections tended to walk a bit. To drive the intake from a 0.5" hex shaft, we bought some aluminum .5" hex gears from Vex and turned the teeth off to make them fit inside the tube (we do not have an arbor press or a hex broach, so this was our poor-man's solution). We initially tried a press fit, but I think we resorted to either bolting it or using a roll pin.