This is a remix of an excellent Lego Duplo to Hot Wheels Hinge Adapter.
Since my son refuses to use the Lego Duplo cubes we have (according to him they are only for younger children) but we really liked this adapter, we have remixed it to be attached to some wooden pillars we had scraps of (in our case 44x44mm wooden pillars).
No support is needed, and we have printed ours in this nice colored PETG.
Most probably PLA would work as well, but in these scenarios usually PETG is better.
Happy to give credits for the original model creator @Timbo
The author remixed this model.
Original model uses Lego Duplo to connect to the pillar, this one has a place for a wood screw with tapered head. Wood screw can be from 3mm to 6mm thick.