If you want to replicate this project, try to get a case that matches the one in the BOM. If you get a similar one, you can modify the panels to suit your size. You can then build upon that.

You can use the BOM as a guide for purchasing the components. The same than step one applies, if you get similar products that don't exactly match the measurements, don't worry. Just modify the CAD model to suit yours. A great aspect of this is that you can cut the same panels but modify the 3d printed interfaces to suit your electronics, or just print covers if your'e not using the cutouts.

3d print the printable parts, cut the panels for component mounting.

Check the electronics fit into their respective parts accordingly. Check the panel sizing with the case.

Attach the electronics and 3d printed parts to the front panel using m2 & m3 screws, and glue the necessary parts. Solder the necessary components after they are in place. 

Start by preparing the top panel, attaching the electronics with m3 screws and epoxy.

Solder long cables (~30cm) to the analog and digital components. It is recommended you solder longer cables than necessary, just in case.

Attach the mid panel using the threaded rods, route the cables through their respective cutouts.

Place the Arduino and Jetson Nano on the bottom stack, where preferred.

Pre-solder plugs to every electronic component (e.g. voltage regulators) and place them on the bottom stack.

Make the connections as preferred. 

Join the 3rd panel to form the stack. Screw nuts on the bottom and the 3d printed ones on top.

Route the cables from the front panel to the bottom stack through the cable cutouts, leave a few inches of cable in between the panels to account for the case opening and closing.

Before putting the panels in make sure to screw the threaded rods into the lid, so that they stick ~3 cm out.

Place the bottom panel first, just slide it in. Then place the front panel and secure it with the 4 3d printed nuts.

Check that you can close and open the case without much resistance.

Install ROS (I used noetic) on the Jetson. Arduino IDE as well.

Flash the Arduino with the provided sketch to test the connections are good. Available over at GitHub.

If everything is ok, you can now make your own software, use the provided Github files as an example to launch everything. There is also the Arduino sketch that shows how the Arduino publishes to a topic.

Make sure to post what you create!

And please add a reference to this project.

Cheers!