As I mounted my new fan duct made of aluminum sheet metal onto my Ultimaker, I found the chance of closing the sides of it with simply adding two sheets of acrylic. BUT: How to mount...?? Screw?? No... Glue? No... Magnets? YEEEAAAA So I designed this simple brackets to glue in the edges of the plywood frame. Each of it holds a small D=3mm s=1mm neodym magnet in place while a counter magnet is glued onto the acrylic window.HowTo:- Buy small 3mm diameter, 1mm high neodym magnets at ebay. While waiting to arrive... - Cut two sheets of acrylic to fit into the frame- Print two sets of the mounting brackets - Push the magnets (as they arrived) into the hole in the print (a bit tight, so push hard...) - Put the counter magnet in it's place on top of the other, it should be well aligned with the surface of the bracket - Glue the brackets in each corner of the frame - Put a small amount of cyan acrylate onto each magnet - Place the windows in its place and wait until the CA is hard- Enjoy a closed UMO :-)