This is the hinge piece german master of craft woodworker L.Kieschnik used for his final qualification build.The hole is 38mm, the pole should be 35mm in diameter.Check out his build on reddit (u/Rainfortxb1) and instagram (Tischlerei_kieschnik)its truely one of a kind design and works beautifully balanced.

Specs:0.15 layer height35mm/sinfill 25%walls 3-4

He worked more than 90 hours on this.