I've spent several years trying to get a drip water logging system working (for cave research). I have a long string of failures under my belt :))

Speaking from my experience.. the actual plastic body of the equipment is the easiest and most irrelevant part. You can 3D print it.. or even just get a bottle and cut it in half? The actual tipping bucket is also kind of ridiculous to make from scratch. There are plastic ones that are injection molded and made for pennies in China. (you'd probably need to contact the manufacturer and make an order of >1K of them). Much more interesting would be a system for calibrating them (hat's not as labor intensive as what they present

Real concerns that need solutions are going to sounds ridiculous but are actually really challenging:

- Moisture will penetrate any enclosure and fry your electronics relatively quickly if you're in the tropics. It's very very challenging to seal things completely. All sealing solutions degrade over time

- People will steal the solar panel within 48 hours. The reality is that nothing about this station needs more than a coin cell (depends a bit on how often you measure the anemometer I guess). Power solutions are not easy or cheap. Weird power issues and making your logging equipment resilient to that is hard

- Most plastics are not happy in direct sunlight. We tried some small 3D printed parts. They all "melted" and fell apart quite quickly (I'm sure some alternate 3D printing material would hold up better)

- A bird takes a massive shit in your rain gauge, what now?

- cockroach crawls into your tipping bucket mechanism and dies. what now?

- Electronics? You know loves electronics? Ants! You're gunna have a nest in all that void space

- free standing plastic enclosures. You will likely have a wasp nest within 6 months

- Exposed cables? Rats will chew through them. Plastic box? Rats will chew through them. Metal box? It'll rust through in 4 months. Where I've tested the largest animal we had to deal with were monitor lizards. I imagine in Africa you have larger animals...

Making an actual low power logger? Surprisingly challenging. The ones you can buy online are 100 USD minimum and use shitty proprietary cables/software. Have terrible power performance and aren't very waterproof

For a more serious look at this space, I'd look here:

https://thecavepearlproject.org/

Also, the most popular rain gauge manufacturer has shifted to tipping buckets to a tipping spoon design.

https://www.davisinstruments.com/products/rain-collector-tip...

I have no special insight in to why. I've look at the internals of both designs and the new mechanism is more complicated (has more component parts). But they no longer sell the tipping bucket design, so I'm guessing there is good reason they did that and there is some advantage (maybe in terms of calibration?)

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holowoodman 6 hours ago | parent [-]

> Also, the most popular rain gauge manufacturer has shifted to tipping buckets to a tipping spoon design. [...] they no longer sell the tipping bucket design, so I'm guessing there is good reason they did that and there is some advantage (maybe in terms of calibration?)

Yes, tipping buckets are less exact than tipping spoons, especially in low-rain season. The bucket is never perfectly symmetrical and the mounting is never perfectly level, so one side of the bucket will hold more water than the other before tipping, leading to asymmetric tips.

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geokon 6 hours ago | parent [-]

Their design doesn't look particularly amenable to tuning though. I'd imagine some design with the weight on a screw that can be screwed in and out to adjust the centerpoint.

The two bucket design doesn't seem overly problematic though. Often you can see this in the record as time-to-tick will follow a sawtooth pattern. I haven't tried it myself, but .. assuming you don't have any skips in your record.. I imagine you could periodically use a long syringe and measure the exact volume that triggers a tick on each side. And then correct the record in software.

A bit of a tangent.. but I've also not found any software or algorithm for correct interpolation of rain volume. Maybe you know of something? ChatGPT suggests a few things :)) but I wonder if there is some standard method people use

	▲	holowoodman 4 hours ago \| parent [-]
		Yes, for larger volumes of rain, that sawtooth pattern is visible and can be corrected for, or even ignored and averaged out. But for low volumes of rain, there will only be one tick. Usually you don't know which side of the bucket that tick was on, because most sensors just count the tipping of the bucket, not the direction or resting position. So for the one-tick-per-day case, you will very often not know whether to count the "large" or "small" bucket amount. Calibration will also be drifting off for dirt accumulation and evaporation. Different fill states of each bucket lead to different evaporation in each bucket (smaller will evaporate faster, deviating towards even smaller amounts), and different resting times lead to more dust and algae settling in the bigger bucket, making it even heavier.