Acrylglas / Plexiglas connectors for Display Case

I used these parts to build a case for my i3 Mega.

I used 500mm x 500mm x 2mm Acrylglas, in Germany just 5€ per glas in Hardware Store/Home Improvement Store Obi or Toom. The base plate in the Picture is the "IKEA LACK" table without legs.

The parts have a gap size of 2.5mm. I printed this with my XYZPrinting DaVinci Jr in 0.4 mm layerheight and 10% infill. With the tolerance of my DaVinci printer the 2mm Acrylglas fit very tight. For the edges I used support.

In my case the screwholes