What we call a G-clamp in these parts but some call a C-clamp for some inexplicable reason.
Originally intended as another camera clamp but looks too multipurpose for just that so I have listed it separately with two versions - with and without the utility lug on the side.
It is quite a complex shape for printing but came out cleanly so must have got something right :)
The internal screw thread is a pair of M8 nuts inside the clamp chamber with a close-fitting cap glued on to hold them in place. The glue need only hold the cover and is not structural.
The hole in the tip is printed at 7mm so either tap it out to 8mm as I did and screw it onto the end of the bolt or drill it to 8mm and glue the tip on.
The screw knob is held in place with a nut on the underside.
The pictures tell this story better than I just have so follw them and you can't go wrong.
Clamp2 is the version that is just a clamp - no tab.
Clamp3B is the version with the tab for a camera on the side.
Clamp3A is the other bits you need to build either one.