Ikea Billy half-shelves

Stop wasting valuable bookshelf real estate !

Those half-shelves will let you put twice as many (pocket-sized) books on your shelves.

They have been made for Ikea Billy bookcases, 80 cm or 40 cm wide (or anything with a 36 or 76 cm internal width, or a little bit higher). The plates' lengths are different, feet are the same for both.

2023-08-16 update : I added a CentralFoot, to avoid having to print two regular feet set back-to-back for two adjacent plates. Still in beta, but it should work.  The CentralFoot must be printed vertically. I've expanded the area touching the build plate to enhance adhesion, but a brim could be useful, depending on your printer and filament.

2023-09-02 update : since shelves may be spaced higher or lower, I have added two sets of feet : 105 cm and 175 cm (approximate total height, with plate). All feet now have the height added to their name. If you got the previous feet set (140 cm total height), no need to re-download or reprint anything, only the name has changed.

To print a full length half-shelf (whatever height you choose it to be) :

• for a 40 cm shelf (36 cm internal width), you will print two side feet, one central foot, and two small plates ;
• for an 80 cm shelf (76 cm internal width), you will print two side feet, three central ones, and four large plates.

You will need four M4 nuts and 4 M4x8 fasteners per plate. No real problem if you do not want to completely cover your shelf's length (as for the lower shelf of the last image, where I used only two large plates).

There is a small M4 hole on the bottom of the side foot, if you want to screw it to the side of the bookcase.

Nuts are embedded into the plates. You will have to pause the print at 5 mm height (layer 17 if using 0.30 mm layer height) to insert them, and resume the print.

0.30 mm layer height, 10% to 15% infill.