Rain Gauge (non-electronic)

thingiverse

Here's a design for an old-fashioned non-electronic rain gauge that you can build with ease. To get started, you'll need to purchase a clear tube, such as a 4' Clear Polycarbonate Tubing, 1-1/8" ID, 1-1/4" OD tube from Amazon (part number B000OMFLE4). You can cut it down to 14-18" and make three of these tubes from a single purchase. The printed parts are straightforward and easy to print without support. I used PETG since this will be outside and will get wet at times, but ABS would work just as well. PLA is likely a poor choice for something outdoors due to its vulnerability to moisture. I used 25% infill for my prints. The top and bottom mounts are designed to screw into a mast or the top portion of a fence. Make sure that the top of the funnel is above any nearby obstacles, like a fence, to ensure accurate rain measurements. Otherwise, wind direction and proximity to obstacles can impact the amount of rain collected. To assemble the gauge, you'll need to glue the bottom plug and top funnel into the polycarbonate tube using hot glue or another suitable adhesive. Be gentle when inserting them, as you may need to heat the tube with a heat gun to complete the process. This technique also works for removing the plug or funnel later, but be cautious not to melt the tube or printed parts. Inside the tube is a measurement piece printed in a contrasting color. When it rains, the 2" funnel area collects Pi*Radius squared inches of rain (1*1*3.14). The empty tube will hold 9/16*9/16" * Pi per inch of height, so 3.19" of height is equal to an inch of precipitation. However, the measurement piece in the tube adjusts this ratio, making each graduation approximately .3". The screw holes for the tube clamp are 3mm in diameter, but #4 screws should also work. I used sheet metal screws for mounting, and wood screws would be a suitable alternative. Now you're ready to enjoy your new rain gauge!