Flood Dog Outdoor Water Resistant Project Case 3.0
I am currently working on a pilot project called Flood Dog in which we will be installing 42 Borons with sensors across the Toronto Islands to measure Ground, Surface and Lake water levels for the next three years. This requires a tough, UV stable, heat resistant and reasonably water resistant case to hold the Boron, Carrier Board, Custom Capacitance Sensor PCB and a LiPo Battery. After 21 major versions and numerous sub-versions (over 120 attempts created and tested) the result is a Project Case that is a ‘thing of beauty’!
(“Post Mount” version side view showing strap holes, post mount option)
(“Post Mount” version bottom view showing wire gland (one in this case) and the locking pin with M3 screw for security)
The case is made of four 3D printed parts: Top, Mount, Bottom and a Locking Pin. It features one, two or no passthrough water tight cable glands for solar power wires and sensor cables to enter the case. The Bottom is a screw on cap with an o-ring seal which provides some water and weather resistance; as this is a custom design, even the o-ring is 3D printed using rubber filament! The Mount slides in/out along a guide track in the Top holding the internal electronic components safely and securely (Carrier Board, Cellular Boron, Water Sensor PCB and Battery).
(Top, Bottom with Gasket, Mount and Locking Pin)
(Mount with Boron, Carrier Board and LiPo)
It’s also somewhat attractive compared to commercially available cases and frankly this is important - just ask Apple. The rounded design makes the case inherently strong; a test case printed with PolyMaker ASA filament was struck with a hammer at its weakest point and after 6 heavy blows the case was only dented, protecting the valuable electronics inside.
Flood Dog cases can be mounted on a post or a pole. The post mount version has a passthrough for either C-clamps, zip ties or wood screws. The zip tie option has been tested and it has proven to be an excellent method for installation. The pole mount design is currently being tested on a Frisbee Golf course and the pole mount has performed well. The latest version features a vandal resistant mounting system to protect these valuable devices from theft.
The most important fact about this work is that everything necessary to build a Flood Dog can be made from locally sourced materials and 3D printed by anyone, anywhere, anytime. While it does take some time to print all the parts for an entire case (14h 40m) the total material cost is under $8. One cannot buy a similar case commercially for this price and certainly not a case that is customized for the application.
Every file and version created is available under an open source license and can be accessed on GitHub. 3D print files and custom printed circuit boards CAD files are available through the Flood Dog repository:
Three Prusa MK3S+ 3D printers have been dedicated to printing the enclosures. To date, over a dozen finished cases have been produced and printing will continue until all 42 Flood Dog enclosures are made!
Thanks to Chip for all his input and experience. I hope everyone finds this a useful project.
philly