Ikea Billy Bookcase 130mm Half Shelf and Brackets

Maximise the display space on your Ikea billy bookcase with a 13cm half depth shelf for the 40cm wide Ikea Billy Bookcase (40x28cm deep version, although should fit the deeper 39cm version but not tested as I only have the 28cm deep versions!)

The shelf is printed in two halves, uses an angular sliding dovetail to connect so the joint is pretty strong and does not flex very much at all, for extra strength there are 3 tapered pins that you push in from beneath, the holes in each side are offset a small amount so when you push them in they pull the halves together and lock it all in place and due to the orientation they help resist bending loads so it should hold quite a bit of weight (not tested how much, but certainly all the Legos you can fit on there!).

Included are side brackets and 4 pins for each side to hold them in place in the shelf holes in the bookcase.

I tried various versions to optimise material use, some with cut outs, a hollow version and a solid version which turned out to be the most optimal, so with 2 walls and 4% infill the pair of shelves use about 152g, this I have found to be strong enough for most use, if you want it a bit stronger use 3 walls which takes it up to about 200g so still reasonable.

I designed it so it is printable on the A1 mini.

80cm version

I have added an A1 and above printer size profile which includes the center pieces which can extend the two side pieces to fit the 80cm wide Billy Bookcase, due to it's length it does flex so would avoid too much weight or if you can prop it up in the middle as shown in the last image that also works. (With the 3 sets shown it flexes about 4mm without a center support so think over time it may sag more so use without a support with more weight at your own risk :)

As always feedback and reviews welcome with any improvements or suggestions and if you liked the model send a boost to support me.