Lampshade reducer ring, 40 mm to 28 mm fitting
A thin ring that lets a lampshade with a 40 mm European fitting sit on a lamp with a 28 mm bayonet holder, the perennial problem when shades and lamps come from different countries. The ring is 3 mm thick with a 28.5 mm central hole, a 45 mm outer diameter and a raised 1 mm lip at 40 mm that centres the shade. Because it sits near the bulb, print it in PETG or ASA and leave small vent gaps in the lip for airflow.
Tell SpeakCAD the hole in your shade and the diameter of your lamp holder, and the ring is generated to bridge them exactly, no filing needed. Preview it free in your browser and ask for a thicker version, a different lip height or a set of three for matching shades.
Create a lampshade reducer ring 45 mm outer diameter, 3 mm thick, with a 28.5 mm central hole. Raised centering lip 1 mm tall and 1.5 mm wide at 40 mm diameter with three 3 mm vent gaps. Chamfer the outer edge 0.5 mm.