igorF2's lamp is a great idea and nice design, but I thought it might benefit from minor changes that would make it easier to print.
This remix avoids fillets on the underside (bed side) that never print that great, instead they are replaced with chamfers. Also, the metric thread is replaced with a nice 45° thread optimized for 3d printing. The vertical holes are replaced with hexagons that can print as bridges instead of overhangs.
Hope you like it!
EDIT 2019-06-01: added source file for Fusion360. To change arm length, edit the "armlength" parameter (Modify -> Change parameters) and then edit the component to move the helix into the correct place.