IKEA Billy: Alternative 45 degree corner fittings/angle joint | Alternativer Eckbeschlag (replaces 401.041.09)

I really don't like the original corner fittings, also they don't allow usage of the original height extension units, so I created this alternative part which replaces 401.041.09.

I recommend to use three of them, one at top, one in the middle and one at the bottom. While the installation can be really tricky, it seems to be quite stable though.

You need to use M4 x 20 mm furniture screws (also “furniture connectors”) and to drill 5 mm holes. For drilling you can use the stencil IkeaBilly_JointsDrillStencilAbove_5mmDrill.3mf:

https://www.printables.com/model/1295917-ikea-metodbilly-drill-stencils-for-furniture-joint/files 

The holes are drilled as normal in a 90 degree angle, not 45 degree.