Industrial vents for model railroad projects. Included are both HO Scale and O Scale versions of a wall mount jet engine shaped vent and a bell shaped roof top vent. They are uploaded by object so select which objects you wish to print. The bell vent is printed in two parts, the bell and the jack, the bell snaps onto the jack after printing. You can reinforce the joint with plastic cement (I've had good luck with Plastruct Bondene).

I printed these on the Bambu Lab A1 with .2 mm nozzle and .06mm layer height. I am also able to print them at .04mm layer height, but unable to upload that profile to Maker World, but it is doable by changing the layer height in Bambu Studio (or other slicer) to .04mm. 

I prefer to print these on the Bambu Cool Plate for a smooth base, but I have also successfully printed them on the Bambu Textured PEI Plate. The file is sliced for the Cool Plate, so if you change plates be sure to update that in the slicer.

When this file was uploaded it was not possible to print this file from the Bambu Handy app, as there doesn't seem to be a way to choose the .2mm nozzle in the app. Until this capability is implemented it will be necessary to open the file in Bambu Studio (or other Slicer) to print the file.