About this 3D model
Please check, if the printsetting are strong enough. I highly recommend to check the print for stiffness, as it migh harm you (and/or break a leg of you/your bed) The wall and upper/lower layers are set to 8, 6 walls, infill at 25% Quite Strong: I modified the model by “FrankTheTank” from printables, so it can hold a felt glider (Filzgleiter is the most german thing, I assume) with 22/23mm diameter. Those can be found at your nearest grocerie, e.g. Rossmann in Germany.: https://www.rossmann.de/de/haushalt-flink-und-sauber-filzgleiter/p/4305615392653