Custom cat door pass through

We are remodeling the house and one of the things we are adding is a closet for the cat box (happy happy!). I wanted a nice way to let the cats in and out without leaving the door open. There are commercial ones out there, but none of them were able to fit the trim on a panel door, and all of them were either round or touched the floor. I didn't like either method. Thus, lots of quality time modelling!

There are a lot of different models, depending on what you want attached to the parts. To get going, print an inside with the hole trim attached to it. Located it on your door (do a good job centering it) and mark the OUTSIDE of the hole trim. Give yourself some clearance; maybe 1/8" radially. I used a roto-zip with a circle cutter attachment and LOTS of passes from both sides to cut the two arcs. After the cutout drops, trim up the short straight sections.

I highly recommend some quality time spend smoothing the layers so your spouse/SO approves. I found a coarse file wor