If you bought a ceiling lamp for the wires that should go from the ceiling, but you want to make external wires connection, there's no need to cripple the lamp or the ceiling, just print this spacer!
Open lamp-extender.FCStd in FreeCAD, click "Spreadsheet" and change all the values to yours:
Diameter - the outer diameter of the spacer (I used my lamp base diameter + 2 or 3 mm).
Width - the width of the spacer (I used 6 mm, and this is enough).
Bridge_height. It's easier to install the spacer without the bridge, but if you need to make the spacer higher than the wire height, use this setting. The bridge will also keep the exact diameter, but without the bridge you will be able to slightly increase or decrease the diameter by increasing or decreasing the hole for the wires (it may be useful if the lamp base is not 100% circular).
Wire_height - the height of your wire (mm). I recommend to add 2-3 mm to this value.
Wire_width - the width of your wire (mm). I recommend to add 2-3 mm to this value.
After entering all these values, press F5, go to File-Export-Stl, save a stl file and print this model that will fit for your lamp and your wires. There's no need to learn FreeCAD at all!
Print time is 1h10m for 148 mm diameter with 0.6 nozzle and 0.32 layer height.
The attached “ready-to-print" stl is for the parameters that you can see in the spreadsheet (see photos). It fits for many Chinese ceiling lamps.
The author marked this model as their own original creation.