Đế Đèn (Lamp Base)

This is a base to those extending arm lamps and magnifying lenses. The hole is 12.3mm.  The base is designed so you can fill it with rocks, sand, steel balls, or other weights.  This lets you extend the arm fully, but lets you move the lamp to more places than clamp bases solutions.

It needs no supports. I printed the base with 100% infill just to make it extra strong.  This was probably overkill, but if you want to never think about it breaking print it that way.

You can use 2 screws to hold the cover to the base, but we find those screws aren't needed since it fits together so nicely.