A Christmas light clip that can be connected directly to the soffit for downward facing lights. These work for soffits that meet with a channel lip at 90 degrees, like the one shown below. They were designed for “LED Vintage C9 bulbs”, but they'll likely fit many others as well.

Subscribers can download the fully parametrized .f3d file, which allows all dimensions to be easily changed to fit other bulbs and soffits.

Printing As-Is

1. Print the “Size Test Plate”, which includes one of each size (standard, medium, deep). 
2. Test each size on your soffit. If your soffit is tight with no gap when you push on it, the standard clip should be fine. If its very loose with a large gap, you might need the deep clip. 
3. Print the ‘bulk’ profile for whichever size you need. 

Changing Dimensions Parameters/Dimensions can be edited to your liking by downloading the .f3d file and selecting the “Change Parameter” interface in Fusion 360 (or via Remixing in Thangs)