I made this yesterday as I've wanted one for ages and finally used some of the 'stuff' I have collected..( I have a reputation for never throwing anything out)
I used a length of plain round rod, a slug of steel ( I can't remember where I got that from), a few nuts, a piece of flat bar and a handle from an angle grinder.
The flat bar yoke on the end has an 8.5mm hole to allow me to attach things, for example, my small vice grips allow me to screw the adjusting knob out and fit it through the hole and reattach them. I guess I could attach all kinds of things.
I've hung it up in my shed, I may not need it for years, I may need it next weekend. As I told the wife, "better to have it and not need it, than need it and not have it"