I got 2 cats with their own schedule, and being their doorman is not on my priorities.

I designed this simple cat door to allow my cats to enter and leave the house freely. Without the need to leave an open door or window.

"The main problem with doors is the strict requirement for a hole in the wall"

Cutting a hole in your door is not an easy task and definitely not a simple decision.

My main issue regarding leaving open door or windows are mosquitoes.

This is how I came to the simple solution to mount a 3D printed Cat door on both sides of a mosquito net.

All you need to do is:

1. 3D print the door parts.

2. Attach them to a screen net and fasten with screws.

3. Cut the net between the two door frames.

4. Convince your cat to give it a try.

Supplies

You will need a 3D printer.

12 M2 8-10mm screws and bolts.

2 5mm magnets (not a must)

Screw driver.

box cutter or X-acto knife.

A screen door would be nice.

Step 1: 3D Print the Parts

The gate is built out of to halves which are connected together with the net locked between them.

Each side is made out of two frames with a hinge connecting them together.

The outer frame will be the door frame, the flip door will move inside this frame.

The inside frame frames the net inside it and become the flip door.

Inside both inner and outer frames there are slits for 5mm magnets (you can change sizes in openSCAD).

These magnets are used to close done the gate and prevent it from flapping around.

Note that the top and bottom parts are not the same! Don't print the same part twice.

There are grooves and ridges on the gate's two parts in order to get a good grip on the mosquito net.

You should print both stl files attached.

You can go to this link on thingiverse for a 3d view of the stl files and get the openSCAD code.

This means you can play around with parameters and change the sizes of the design!

if you don't know what openSCAD is, it is a programming language for 3d modeling.

Very awesome, start here http://www.openscad.org/

Step 2: Mount It on Your Screen Net

Decide on which height and location you want to place the gate.

Its top should be somewhere near the height of you cat's head.

Put both sides of the gate on both sides of you net.

If you are planning to add the magnets now it'll be a good time to mount them to their places, it might be helpful to glue them to one side to prevent them from falling while adjusting the frame.

When placing the magnets MAKE SURE you are putting the in the correct polarity. They should attract each other to keep the gate closed. (see magnets location on the right hand side of the attached figure)

You can use pins or some thin rods to hold it temporarily while adjusting the height and location.

When you are happy you can start screwing the screws. Do opposing corners first to make sure you are not pulling the net while threading the screws.

Now cut the net between the frames using a box cutter.

You are all done!

Go get your cat ;)