This is a simple FPV racing gate that I drew in Sketchup.

If you're interested, I have a heavier modular FPV door

Modular FPV Drone Racing Gate - Free 3D Printing Model - MakerWorld

Each segment is 175 mm long, so it can fit on an A1 printing board. Each ring requires printing of 8 segments. They can be pushed together and have enough resistance to stay in place, but disassembling/installing them is very quick. I used squares as connection points so that the octagon wouldn't sag when setting the angle. The inner square is 5 mm, and the snap-in square is 4.9 mm. It printed perfectly on my A1 mini using PLA. Please note that I selected the standard 0.2 mm layer height setting and default infill, but set the layer walls