This model is a very simple riser for LG OLED C2 42" so that you can place soundbar below it :) 

It is 60mm high and rises the TV by 40mm. It is very stable thanks to 20mm deep slot for the TV legs. I tried to rock the TV, but it did not wobble a bit.

Printing

• 40% infill
• 5 perimeter walls
• 4 top layers
• 4 bottom layers

I would advise sticking some rubber or silicone pad that covers whole bottom of the riser, so that TV won't slide easily. I would avoid using multiple smaller pads as they could introduce some instability, unless they are flat and will create uniform surface.

Editing

This model can be edited in Onshape: https://cad.onshape.com/documents/3ea4ee036a6c860a26d647be/w/bbfa7cd929773b708ac262c2/e/828c993901370e122aa83705?renderMode=0&uiState=655a894b4b12c8363cb73fe0

If you want to make the riser even higher I would seriously consider adding horizontal feet at the ends.