This is an angle bracket I used for several projects. The bracket is created as parametric model in FreeCAD and can be adjusted to specific needs by modifying the dimension parameters. Additionally I attached an STL and STEP file for a specific configuration of the bracket with 50x70mm outer dimensions, 3mm thickness and 4mm hole diameter.
For generating the model matching to your required dimensions first open the attached FCStd file in FreeCAD (created with FreeCAD 0.19) and click on the “Dimensions” entry in the tree to open the spreadsheet. You can place the 3D view and the spreadsheet side by side via the “Windows” menu.
In the spreadsheet you'll find two types of parameters:
The following image shows how the parameter values affect the bracket geometry.
The bracket is designed to be printed in upright orientation without support materials. This way the layer direction should be best for absorbing the static loads on the bracket. For avoiding large bridging distances a support bar is added at the lower side.
I printed it with PLA and 0.2mm layer height. Since the contact area to the print bed is small I printed the part with 5mm brim, but it might also work without.
The author hasn't provided the model origin yet.