Here we have my Gantry mounted LED light strip. I designed this for my Ender 3 but should fit onto any 2020 or 2040 extrusion. I merged my 'shade' design with the beefy hinge design which gives it a good solid mounting point. You will need to print one bracket and one shade for each installation. The two pieces fit together snugly with some friction but the long bolt provides a hinge point and just that little extra squeeze. The hinge can be moved - but it will not droop on its own.
Two orientations are provided for the shade (one has the USB opening on the left, and one has the opening on the right - otherwise they are the same design.)

See post print notes for some assembly details.

Note that this design was built around these LED strips. (other strips would work but may require tweaks)

https://www.banggood.com/20CM-Mini-USB-White-Portable-LED-Night-Strip-Light-Bar-Studio-Cabinet-Closet-Lamp-DC5V-p-1202488.html?rmmds=search&cur_warehouse=CN

Key points why I chose these LED strips.

• 200 mm long by 15 mm wide rigid PCB is a perfect size.
• A very bright cool white light which is also perfect for this application
• Cheap to buy (and can be used for other things)
• The dual row staggered pattern LED's gives lots of uniform brightness.
• They work on 5 volts (USB powered) with a built in micro usb connection.
• They do come with sticky back foam strips attached - (Usefull in other cases but but here we do not need to peel of the backing strip to expose the sticky part - we just don't need it.)

At the moment my LEDs are powered from a "USB power bar hub".
I intend to tie in to my 5 volt supply that is currently powering the raspberry pi.
That way the lights will come on automatically with the printer.

Creality

Ender 3

No

No

0.2

20%

Draft Mode worked fine (which for me is 0.2 mm 20% infill, moderate print speed.)
Color is not important - your preference.
No supports are needed when slicing because my design has supports built in.
(I used small cones to helping hold the roof up in the lamp shade).
I found this much easier to work with than letting the slicer fill the cavity with supports which did not come away cleanly..

Are held together with a M5 x 50mm bolt which acts as a hinge and proves a tiny bit of extra friction on the hinge. Hinge can be moved .. but wont droop on its own.

Note:
Two variations of the shade are provided, one with the USB opening on the left, and one with the opening on the right. To mount on both front and back of the gantry frame as I have done you will need one LH shade, one RH shade and two brackets (plus LED strips and hardware of course)