Custom dog door panel with a WiFi lock

A catalog dog door is a handful of widths. The opening you actually have is a sidelight, a chewed plywood insert, or a door slab thicker than the frame the pet door was molded for. The search that lands here usually adds a second wish: a lock you can check from a phone. Both are solvable if you separate them. The custom part is the panel. The lock is a product someone else already tested.

This is the same loop as the rest of vibe manufacturing: measure, ask for a draft file, prove it in cardboard, then pay a shop. It is a bad loop if you ask the model to invent the latch.

The problem

The mismatch is almost always one of these:

• The rough opening is not a standard pet-door size.
• The door is too thick, or too thin, for the tunnel on the pet door you like.
• You can replace a panel and you cannot replace the whole slab. Rentals and sidelights fall here.
• You want a status you can see from work, which a dumb flap does not give you.

What you are making is a flat insert with a cutout, screw holes, and maybe a separate adapter plate for a commercial pet door or a commercial electronic pet door. What you are not making is a new lock mechanism, a new radio, or a new weather seal. Those parts have springs, gaskets, and a defined behavior when the power goes away. A generated solid model will not discover that behavior.

If the “WiFi lock” you want is a separate smart lock, the custom part is still only the plate around the lock’s own strike. Use the lock the way its maker mounted it.

Workflow

1. Measure

Write millimeters or inches at the top of the page and do not mix them. Record:

• Width and height of the opening the panel must fill, measured in three places. Use the smallest if the frame is out of square, and note the gap.
• Thickness of the door or the stop the panel bears on.
• Which way the main door swings, and which face the lock will sit on.
• Threshold height, and the dog’s shoulder height plus a little clearance so the back does not scrape.
• The ribcage width of the dog, not the width of the collar.
• The actual pet door or lock body on the bench: flange size, screw pattern, and tunnel depth. Measure the screws you will use.

Photograph the tape in the frame. Glass is a stop sign, not a measurement exercise. If the only way through is a tempered pane, this project is the wrong project.

2. Prompt for a CAD file

Ask for two flat parts, not a mechanism. Demand STEP and DXF, in the unit you measured, and tell the tool the lock is purchased.

Draw a flat exterior panel, 3 mm aluminum, 480 mm wide by 620 mm tall.
Cut a centered rectangular opening 280 mm by 390 mm for a purchased pet door.
Add 8 holes, 5 mm diameter, on the pet door's flange pattern, which I will paste
from my measurements. Add 6 mounting holes, 5 mm, 15 mm in from each edge.
Do not design a latch, spring, motor, or seal.
Export DXF in millimeters and STEP. Label the unit in the filename.

Replace every number with yours. If the assistant returns a rendered picture and no file, you are not done. Open the DXF in a viewer before you admire the picture.

3. Prototype

Cut the opening out of cardboard or foam board at full size. Tape it in the frame. Walk the dog up to it. Check the bottom edge against paws and the top edge against the back. Print or cardboard-cut only the lock plate if the commercial door is already in hand. A full-size metal panel is an expensive way to learn that the opening was 10 mm low.

4. Review

Confirm the file’s units. Measure three hole diameters in the viewer and compare them to the screws on the table, not to the nominal size you typed. Check the shop’s minimum hole size and the minimum distance from a hole to a cut edge. Look at the pet door’s instructions for frame thickness. If your panel plus the door skin is outside that range, the custom part needs a spacer or a different commercial door, not a thinner fantasy flange.

5. Send it to a fabricator

A sheet shop that laser-cuts or waterjets aluminum is the usual match. SendCutSend is one example of that category. A local sign shop with a laser is another, and you can stand there while they cut a scrap first. Order the commercial pet door from its maker. Do not ask the sheet shop to supply the lock electronics.

If the first plate does not match the flange, that is a revision, not a scandal. Keep the commercial door. Change the hole pattern.

The same habit shows up in a van accessory bracket: the custom file is the plate, and the certified hardware stays certified.

Tools and services

• Tape, calipers, and the pet door or lock on the bench.
• A CAD tool that exports DXF and STEP. FreeCAD and Fusion 360 are common. A text-to-CAD assistant is fine if it actually exports those files.
• Cardboard for the full-size check.
• A sheet-metal or laser shop for the panel. Read their current materials and design rules.
• The commercial pet door or electronic pet door, bought as a product.

A print farm can make a jig or a temporary interior cover. PLA is a poor exterior door. Sun, rain, and teeth are not a desk environment.

Cost and time

Estimate, not a quote. A small aluminum panel is often the cheaper line. The commercial pet door or electronic door is often the larger one. Paint, fasteners, and shipping sit on top. A planning range of roughly $80–$250 before shipping is only a way to decide whether to measure this weekend. Your alloy, thickness, and the door you choose will move it. Ask the shop.

Estimate, not a schedule. Measuring and a first file can be a day. A cardboard check is an evening. The shop’s queue is whatever they quote. Plan on a second file. People who budget one uninterrupted afternoon are usually waiting on a revision or a delivery.

Pitfalls

• Designing a latch, motor, or seal from scratch because the prompt was ambitious.
• Cutting glass, or drilling a tempered pane, from a vibe file.
• Mixing inches in the sketch with millimeters in the DXF.
• PLA, or bare plywood with no finish, on an exterior door.
• Ignoring what the commercial lock does when the battery dies. Some fail so the flap still opens. Some do not. Read that before you rely on it.
• Treating a phone notification as proof the dog is inside.
• Forgetting the landlord, the insurer, or the fact that a pet flap changes how that door behaves in a fire exit. If you do not control the door, do not cut it.
• Chew height. A dog that already destroyed the last panel will destroy a pretty one unless the material and the tunnel are chosen for that.