The adapters are intended for use when aluminium profiles are to be used instead of pipes.
The parts are printed with the same settings as the rest. First they have to be screwed onto the aluminium profile, then the corner can be mounted.
If there are problems with the nut holding in the part, it can also be fixed with a drop of instant adhesive.
I printed it upside down, without support.
The author marked this model as their own original creation.