Print with ABS, ASA or any other high-temperature filament, with 100% infill.
No Support needed, I printed with Support, my ABS has Layer adhesion issues.
added a Version without dowel pin hole
added a Version V3
V3 removed - construction failure
The author remixed this model.
Unfortunately, I had stability problems with the first design, so I closed the slotted hole, reinforced the underside by 1mm and drilled an additional 1.5mm hole in which a dowel pin 1.5x14 or longer can be inserted for reinforcement.