Print without supports. Print with the minimum number of 3, you can add more if you want.
Install:
Hold your guitar to the wall, then draw 3 points for anchor points. Example is given in the photos. Then drill those holes and insert dowels. Then insert the screws and tighten them until you see only the head for 2 or 3 mm(also figure in the pictures). Then just slide the holder into the screw. If it looks loose, tighten the screw a little bit until you think it is enough.
The author marked this model as their own original creation.