Summary I just installed a new range hood. The new hood did not come with a damper so I bought one made out of sheet metal. It was awful. Any advantage I had in buying a new quiet range hood was nullified by constan ting, ting, ting of the metal damper! Arggh! So then I thought "what if I made a damper and printed it?" Ah hah, a new 3D printing project! I was extremely pleased with the results. It is unlikely that I will ever print more than one of these and it's not the sort of thing that most people are going to need but I'm uploading it here on the chance that it might help someone else with a similar problem. Print Settings Printer: Prusa i3 MK2 Rafts: No Supports: No Resolution: .350mm or finer Infill: 20% Cubic Notes: Printed on a Prusa i3 MK2. I used ABS for this project. (Scale up by 101% for shrinkage.) PLA or PETG can be printed at size. Print one base, one ring, and two flaps. If your range hood accommodates 3-1/4-in x 10-in ductwork, you may have to print the wings to cover the wide hole. Post-Printing Assembly This design uses thin stiff wire for the flap hinges. I had some spare 15ga. bicycle spokes that I used, but a suitable diameter of music wire would work (available in hobby shops.) Cut the wires to length and insert in the holes in the base and flaps. Slide the ring down over the wires to keep them in place. (You may wish to glue the ring if you want to make it permanent. Customization My particular range hood is a GE model JVX5360SJSS. This design can be customized for other hoods with 7" diameter ducting by modifying the design to place the holes in other locations (or you could print it as is and drill new holes in the plastic. My range hood could also use 3-1/4-in x 10-in duct and the hole in the top of the rang was a combination of both types. This necessitated design some "wings" that screwed down over the part of the hole not covered by the damper. You may not need these parts depending upon the design of your range hood.