I have been asked to have a look at turning one or two of these.........
I might give it a go; little reference to go on but for a few forum discussions where no one really discusses the sizes but complain about the poor quality 3d printed rubbish available on eBay.
Solid aluminium is the way to go (but maybe a sandwich affair of rod and discs might be easier).
I have looked at a few screen grabs from different sources and have come up with the dimensions in the image and download PDF.
What say you? What do you think?