Greetings from New Brunswick in eastern Canada. I am a beekeeper and like many beekeepers, I like measuring and tracking my colonies however I can. I have been looking at ways to measure weight for a while. I have checked many other sites and projects and I am sure you know them all, the Swiss load cell (expensive) system, Arnia, Hivetool.net, the hive scale work in the US hosted by Bayer, solutionbee, Arduino threads.... etc etc. Some of them look nice, but are too expensive. Then there are lots of questions on the load cell performance and especially affected by low temperature.
Your system stands out, being mechanical. I like simple, mechanical solutions. So I got excited. But I do have some questions that I hope you can answer.
1. Data. The system looks good, but you provide no actual data obtained by using it! Surely you must have lots of data to show how it works in practice? The test/calibration is fine, but not the same. I want a system that will work all year so I want to see datasets showing how it has performed in real world use.
1a. More regarding data - the system seems to have no data storage/logging capability. Is this correct? So you only get a single reading when querying it?
2. Levelling. You don't say anything about this, and there seems to be no level adjustment provided in the design. How sensitive is the scale to changes in level? Through the year there is rain, frost, drought etc that can tilt support structures. How to deal with that?
3. Cold weather performance. The system uses a rubber belt. What happens when it gets cold? I don't mean cold for Bordeaux I mean -20C and below. Has it been tested in real cold weather? At present I am doing some research on winter hive ventilation, and for this I would really like to measure small changes in mass due to loss in water vapour from the hive. For this the scale needs to work reliably all winter.
4. Access. It looks like the 'brain' and power supply are not accessible unless the hive is removed. Is this correct? If so I don't like this part of the design. When things go wrong I don't want to have to remove the hive every time to check things. I would prefer to have the control module external.
5. Exposed wires and drive system. It looks like there are several vital wires that seem to have no protection and maybe also the belt drive. I am thinking of mice chewing the wires and plants growing up underneath and getting messed up in the belt drive. Where I am we have many chewing animals such as porcupines that are notorious for chewing plastic. I don't think they could get in, but mice, voles and shrews could. Just a thought.
Connectivity....I don't understand a lot of those options but would probably use wifi via home router (I assume that would work?) I have other bee yards about 15-20 km away , is that too far for the LORA system?
I think you have a very nice concept and I would like to evaluate a unit, look forward to your reply.