It would be helpful for you to describe your project.
A hollow tube is one way you can implement what I think you are trying to do, but it is not the only way. Assuming a tube and a common, inexpensive slip ring like this one…
…then your description of the implementation would work. The larger base of the slip ring would be attached to the base below your turntable, and the hollow tube would be attached to the smaller “nipple” pointing left in this image.
But there are other types slip rings, and some interesting DIY slip ring solutions that might be a better fit depending on your project.
FYI: I did a quick scan and found around ten project on Thingiverse that use slip rings, but I don’t think any of these projects are helpful for understanding your specific project.