Here are some .STL files for center vents. These are meant to match up as close as possible to the OEM ones. I have yet to finish optimizing these as an assembly, but they are close. I have test printed these with PLA, the pivot point on the frame piece may need some tweaking to have proper tension. Here is a pic of them in Bambu Studio. Just clone the outer baffles, need 4 of them and 1 center baffle. Gear snaps onto center baffle, knob snaps into outer shell. Baffle tie bar is a tad too thick to be honest, needs to be adjusted so it doesn't pop off the baffles. Anyways not too bad for a first couple rounds of editing. Enjoy.