Rain gauges are devices that measure the amount of rain fall. A widely used type is tipping bucket gauge. For information see here, here and here.
I decided to build one with materials in hand. I designed the bucket with LibreOffice draw to have a base to build on.
The bucket is the part that will be in contact with water, so I can’t use MDF, soaks water and it will be destroyed fast. Some plastic is better. I found in the garage a plastic bucket lid.
Flat, soft plastic. Easy to cut. I glued the parts with hot glue. Also I kept a big acrylic from an old door and I cut from that the base to hold the bucket. To glue acrylic I used CA glue. For the axis of the bucket I used a 4x50mm screw. The result is pretty and it works, at least with small flow of water.
After some testing, I added adjustment screws to level the bucket.
Next part is the funnel. I found in our recycle bin a yogurt cup. Top diameter is around 80mm.
I drilled a hole in the bottom and hot glued a coffee straw. I tested it with bucket, but the flow was big and the rotation was not working. So I narrowed the straw hole with a piece of heat shrink tube that matched perfectly the inner diameter of the coffee straw.
The flow is now perfect and the bucket tilts nicely.
The funnel and the final tube might seem small, but after checking the statistics for my city is more than enough. Yearly rain fall is 185mm and max daily is 27mm. The funnel fully filled with water is way more than that and takes 2min to drain. I think I will be OK.
