19mm or 3/4 Square Aluminum Tube Corner

I remixed Sandfrogs 19mm Frame Connectors to make 19mm Corners.

UPDATE: I updated the OpenSCAD file to make it easier to configure for different tube sizes. Now you just change your Tube Size and Wall Thickness to change corner.

Slic3r Support settings
Pattern: rectilinear
Pattern Spacing: 2.5mm
Pattern Angle: 0
Interface Layers: 1
Interface Pattern Spacing: 0.5mm
Don't Support Bridges: Checked