IKEA lampshade adapter for use with pendant light fittings

We went to IKEA last week and bought a number of lampshades - and completely forgot to buy some adapters to fit them to our ceiling pendant light fittings. Looked around various places, but couldn't find an adapter I liked, so designed my own in OpenSCAD.

The original IKEA adapter from which this was remixed was perfect if the lampshade was being mounted on a lamp base or stand. However, if the shade mount was swivelled around so that it could be used with a pendant ceiling light fitting then the adapter wouldn't fit properly, due to the shape of the shade's fixing ring and the two bars that support it. I could have used the original design inverted, but I would prefer that the shade was resting on top of the adapter, rather than hanging precariously on the clips.

This adapter has an indent instead of a raised centre, together with a couple of grooves for the bars.

It should ideally be printed using a material that isn't too brittle - nylon is perfect if you can print it, but ABS works, as does PETG at a push. The pictures show two adapters made with white ABS, and one in translucent PETG and all have been used successfully.

PLA and PLA+ are far too brittle for the first adapter with its springy catches, but if you don't have nylon, ABS or PETG then the second glued version can be used. With this the plate is held underneath while the clips are glued on with plastic solvent or cyanoacrylate glue. This works, but it will be permanently fixed afterwards (the other adapter is removable).