The Adjustable Clamp Head
Replaces a C-clamp's flat pad with a vee that grips round stock instead of sliding off it.
The problem
A C-clamp ends in a flat swivel pad, which is exactly right for a flat board and exactly wrong for anything round. On a pipe or a bar the flat pad touches at a single point, and every turn of the screw tries to squirt the workpiece sideways out of the clamp. The usual fix is to jam a scrap of wood in and hope.
The insight
Make the head the shape of the problem. Two arms drop either side of the contact point so the pad becomes a vee, and then tightening pulls the round stock down into the vee rather than pushing it out. The force that used to cause the slip is what does the holding.
How it works
- The head takes the place of the clamp's existing swivel pad.
- Two arms descend from it, one on each side of the centre line, forming a vee.
- As the screw drives down, both arms meet the round stock on opposite flanks at the same moment.
- Two opposed contacts cancel each other's sideways push, so the stock is captured instead of squeezed out.
- The head keeps its swivel, so it still tilts to meet stock that is not square to the clamp.
Materials and process
Modelled in SolidWorks. No physical part exists — this one never got printed.
What exists now
A finished model and nothing else. It is here because the move it makes is worth showing and because a museum that only exhibits what got built is telling half the truth about how a practice works.
Next: Print it. It has been ready to print since February 2025.
Evidence of making
