Remix on Nate's design, but in Fusion 360 and parametric. The inner diameter, thickness, and width are all parameters in the fusion file. There is a low poly .stl in there for an example. Size the diameter to your liking, export as STL. Then bring that STL back into fusion and edit the mesh selecting just the outside face to run a reduce command on. Set the face count to how low poly you want to go and then your off to the printer.