Projected for monitor with 23,8". I add my project file from FreeCAD for your easier modiffy. Device holder is printing with  adjust screw, after print it take a little perswasion to lose it but at least for me it's work (I use blade and a little hammer at  end of screw in place where it touch mount).

Printing:

• device mount must be placed in the way that screw will be vertically;
• I use PETG, but PLA should work as well;
• at least 15 % infill;
• don't use support;