As part of a recent house move, I bought a new bed and reading light from Ikea. The popular MALM bed frame and a JANSJÖ clip-on light. Only after everything was assembled did it become apparent that the JANSJÖ is not compatible with the thick MALM head board.
Rather than return the light, I set out to create an adapter that would allow me to use the light with the bed head.
The first two iterations were designed with a bending point located at the top of the adapter, so that the pressure from the clip would translate through the adapter to secure it in place. In practice, the length of the light arm acted as a large lever creating a lot of force when manipulated. When coupled with the long thin sections of the adapters, this caused them to be unstable and detach easily from the bed frame.
The third iteration addressed the flexibility of the first two by increased the wall thicknesses significantly whilst using the same clamping mechanism but with a steel fastener for increased force. In practice, the clamping location caused the arms of the adapter to deflect, decreasing the effectiveness of their grip.
The fourth iteration retained the thick walls but uses a direct clamping mechanism. The original intent was to avoid this to prevent any damage to the bed head, but the soft PLA material and large bolt diameter appear to have minimal effect. Even without the bolt, this adapter works well with movement directly perpendicular to the adapter, while the clamping helps with side-ways movement.