T i m brought next idea :
Did you buy it or make it OOI Harry?

I made it, partially on the lathe, a tapered nose, then steel tube and
threaded rod. Copied from the photo of the commercial version.

There is a much less intricate version to DIY, which I intend to build
and test. A problem I noted with mine, was that it was difficult to get
it to hold the two wire ends tightly enough. They tend to slip once you
begin tightening with the screw. It does need around 45 degrees of
freedom of axial rotation around the pipe, to finally lock the wire
tension once tight, so you need to allow for that when you begin the
tightening stage.