How can I take apart the pictured bed frame joint? It doesn't have visible screw heads on the outside of the footboard (image 1), and the recess in the runner that contains he screw is covered by some kind of lock (image 2).
I tried turning the hexagonal opening with an Allen key, but it doesn't move for more than half a turn.
It's a cam lock fastener. It is locking down on a stud bolt which is perpendicular to the axis of the fastener.
You only turn it about 1/2 turn to release it. It then releases the stud bolts, which I gather come from the right in your picture.
With a hex key turn the fitting CW to a stop or or 90 deg and the cam lock should release.
