This is a remix of the Nikon APS-C viewfinder hard cover ( https://www.thingiverse.com/thing:1587542 )
I wanted to make a hotshoe-mounted selfie mirror, since the entry-level Nikon DSLR do not have a pivoting live view screen. This cover seemed like a great head start, so I didn't need to model the hotshoe or the hinge. However, it was too small to be useful with a mirror attached.
I sliced the original cover STL into two pieces, the hinge and actual cover. Then, enlarged the cover to allow for a larger mirror, and re-attached it.
The cover should now serve as dual-purpose:
-Flip down to cover the viewfinder, keeping it from leaking unwanted light with long shutter exposures. It will block a small portion of the live view screen though, so frame the shot before flipping it down.
-Flip up to use as a selfie mirror. It's not perfect, but it's easy to carry and does the job.
Tested with Nikon D3500. It will probably work with other D3*00 cameras.
Anycubic UV Resin
Prints flat on the bed without any supports for DLP/SLA. For FDM, not sure if supports are needed since I don't have one.
-Sand and paint black if needed
-Find a cheap plastic mirror that's at least 1.75" x 2", such as one from the dollar store. Alternately, you could use mirror paint if you have it.
-Using your preferred tools, cut the plastic mirror to 1.75" x 2"
-Cut a piece of black felt or construction paper to 1.75" x 2" as well
-Using super glue, attach the mirror to the outside (flat) part of the cover. Try to use it sparingly and without globbing too much in one area to minimize the warping/distortion of the mirror.
-Using super glue, attach the felt to the inside of the cover
-Use a bolt & nut to connect the hinge together. I used a 6-32 x 3/4" but it was slightly too thick, so I needed to drill out the hole slightly larger. A thinner bolt that's 3/4" long would probably work better if you have it.