Lucky ones with the beehive scale say it is very useful tool of the trade. However the proper beehive scale construction is not easy to achieve as you will learn from my experience in the following text!
Inappropriate beehive scale design solutions
In making the proper choice of beehive scale it is advisable to study my previous solutions because there you will find some of the important principles suitable for other scales as well. That way you can find the right solution for yourself!
We shall exclude from this text the expensive fancy electronic scales which are permanently positioned under the hive. The price of those is such that their usage is mostly discouraged. Here we are going to discuss the cheep and efficient scale that you can make yourself or one somebody can make it for you.
Even the large beekeepers with certain and always unsufficient number of electronic SMS scales can benefit of portable and cheep beehive scale that can weigh hives in about two minutes per hive.
The previous solution of mine: the scale with lever
The scale with lever uses dynamometer (luggage scale) connected to the lever from above. The lower part of dynamometer is connected to the steel profile which can slide vertically and have the small pull up arm under the hive. By lifting the arm we are lifting the hive as well and obtain the value of roughly half of the hive weight. By means of butterfly nut the hive the maximum lever upper position is determined. That way the lifting will always be to the same height. Here is the problem with all this: the aforementioned scale have inconsistent measurements! What that means is the differences between two measurements of the same hive are 1kg, 2kg and even more. Consequently the scale is not suitable for most precise beekeeper's measurements.
What can we learn from this example? The reason for inconsistency is the existance of multiple support points: two points wide left and right under the hive, as well as lever depending of variable mechanical force produced by your hand. With all these factors acting simultaneosly even a part of millimeter in lever position matters and lead to large weight difference! The existance of stopping screw which determines the height of lifing does not solve the problem in practice. Shortly put the system is too sensitive and depends on variable parameters of construction to be of any practical use.
The balance scale
On the right side of the picture is another previous solution of mine: the balance scale (sort of). The longer arm of this scale contains the measuring tape. Two shorter arms are put below my hive. By hanging the fixed weight (5kg) on variable places along the longer arm until the hive is separated a few millimeters from the base, or by hanging a dynamometer on the fixed place of longer lever and dragging the dynamometer until the hive is separated from the base, we obtain the half of the hive weight.
Is this simple system suitable for us? The answer is: NO!
In this system we have the action of physical forces extremely sensitive to leveling. Accordingly the scale is not suitable for practical use.
The beekeeper's scale with ordinary body scale
In the picture on the left, as well as in the left side of the picture above, I show the construction of jet another scale of mine that has the separate lifter similar to the previosly mentioned balance scale. Body scale is put on steel tray showed in picture. By means of lifter arm we lift the hive with one hand and with the other hand we put the body scale on the tray under the hive and read the half of hive's weight. Is this the solution we seek for?
The answer is the same: NO! In my attempt to find out the solution with body weight, I did not took into account the crucial factors for body scale functioning: the hard base and the 4 support points leveling namely. Pay attention on the fact the hives are normally always inclined towards the entrance. Also the ground and the grassy terrain always presents variable support. From those reasons the body scale is not suitable for these measurements.
The other guy's Internet solution: scale with steel cable
Is the Internet solution published on site Beehacker according to a patent the one we search for? All we need to check is the finishing quality the scale can provide.
The author quotes the standard deviation 0.72 pounds, e.e 326g. As far as I recollect the statistics, 3 times standard deviations contains most results of measurements (99% or so). Consequently ±978g is the range of measurements obtained with this solution. In my understanding that is hard to accept for practical implementations.
Where is the fault in his construction? IMHO the measurement depends on cable elasticity, leveling and the manually fixed end positioning. All these are wrong construction ideas.
Yes, finally: the real solution of beehive scale -Slavne Scale
As you can see the aforementioned faults are more or less removed with my final solution of beehive scale constructed as exposed on pictures above. By means of lifter you are going to lift the hive, and with the other hand you shall put the metal tooth under the hive. This tooth is connected to the lower part of luggage scale and it's construction would permit the safe hive support. The lifter arm should be put in neutral "gear" position and read the weight of half of the hive.
This time you will read the more or less stable weight with about 10g variability! Compared to the Internet solution above that is only 100 times more consistent than measurement presented on Beehacker site. Is that good enough for you?
And a few more Internet miracles
Now take a look at few solutions from Internet on pictures below. I quoted in this text what are the construction problems and now you should try intuitively or on the bases of my previous comments to comment for yourselves the practicality and accuracy of other Internet concepts in relation to my solution. On the bases of the previous text you can immediately find why the other solutions are unacceptable: