If you make this model and like it, please post your make and rate the model, that would make my day!
I needed to join a cut/open faced Lack leg to the bottom of another leg and I came up with this model.
There's no screws or gluing with this but it does use (free) 30x8mm dowels (part #101350) that you can grab at the Ikea spare parts wall on your way out.
I printed them with the open cavity face down with supports, I did it that way because I didn't want any rough surfaces left over from support material in the narrow gap that might obstruct the fitting of the leg. Maybe it's possible you could print it without any supports with the other face down but I'm not sure, I'm no expert and the slicer was telling me no.
I printed these on a Prusa MK3S+ using the following settings:
The author marked this model as their own original creation.