This is a stub for the Smart Portable Bee Scale Project so that readers can post questions or comments. Look for other postings to emerge as this project matures.
Keep a lookout for the following in future posts:
- Measuring and improving the accuracy of the device
- Actual hive measurements – what do they mean?
- Design of a non-portable, continuous logging scale
So whaddaya say?
November 23, 2014 at 5:07 am
My portable scale costs $16 and ten cents. Measures the weight of a hive up to 200 pounds in five seconds. Fits in my back pocket. I took a steel eyelet from Lowes and screwed it into the back of each hive bottom board. Put the luggage scale with lock feature hook into the eyelet, lift and press the button. I take this reading and divide by .57. The result is the weight in pounds. The reason I can’t use .50 is that my bottom boards have a 2.25 inch porch on them which shifted the center of gravity. My mentor has 2 hives on feed scales in his yard, and we tested the reading ten times with this method. You are right about the need to know the weight going into winter and the weight loss each week during winter is the most important use for this tool. In Alabama, we like to have about 60# of honey in the hive to make it to the dandy-lion bloom; and that is all I need to know. Your hive going into winter is just two or three supers with the winter stores and the bees, and that should be less than 200#. I sell and ship a lot of woodenware, and two supers, top, bottom and inner cover are about 70#; the bees and pollen less than 10# so that leaves room for about 120# for honey within the limits of the scale using this method. Get the scale with a steel hook and not a strap, and the one with a nice plastic handle with the hold weight button. The others work, but the steel handle bites the bare hand. Don’t even need to suit up, just slip around the back of the hive and the bees never know what happened.
April 17, 2014 at 10:07 pm
Scubajohn,
Here are a few ideas. What we are seeking here is relative accuracy or repeatability. Unless you first weigh your hive on a calibrated scale, we don’t really know if the starting weight of the hive is 49 pounds or 63. But that’s ok because we want the difference between measurements made on different days to truly indicate a change in the weight of the colony – that mostly indicates a gain or loss of nectar/honey/water.
I used a 45 lb wood planing machine for testing. If you don’t have one of those, use a stack of bricks or something else.
First make several measurements. How far apart is each one? They should not deviate more than 1 or 2 pounds max. The purpose of the bubble level and the limit stop is to insure that consistency exists in making measurements each time.
If the slot is too large, the fork may be extended to its limits and that is a problem. Keep the slot as narrow a possible. The middle fork needs to raise only enough that it lifts the back of the hive. Any more than that and inaccuracies can creep in.
Does the wood lever or metal tongues bend? If they do, they are too thin and will give you a different weight each time. The lever and tongues (fixed and moving) both need to be stiff and non-bending. I used 3/4 inch plywood. If you are using wire cable, there should also be no stretching. Nothing should bend or stretch between the lifting tongue and lever.
With respect to factoring, I *may* weigh an empty hive before it gets a new package or captured colony. That gives me a baseline. Otherwise, I use the value from the hive scale and go from there. From that point on, every time I add or remove a super, I weigh the before & after and record it in a spreadsheet. That way, I know if a drop in weight was due to removing a super or losing a swarm.
I hope these ideas help.
April 17, 2014 at 1:02 pm
I am having a bit of troulbe with calibrating the scale I built from your design. Can you elaborate a bit more with how you calibrate and what kind of factoring you have to do?
February 5, 2014 at 4:27 pm
Well, I finally got mine built! Found a 330# capacity scale for $70. Overall spent about $140 with SS hardware. Seems pretty accurate. Measures the same every time, double checked it with a bathroom scale and it was right on. I am looking forward to having it in the fall and next winter. How do I attach, send a pic?
March 19, 2013 at 8:12 pm
Jamie,
Thanks! The steel straps and 3/4 European plywood (more, thinner plys) are pretty strong and should be good to 200 lbs (a 400 lb hive). The limiting factor is definitely the $16 luggage scale. I have seen load cells that might work. Good luck and send me some pictures when you get it built.
March 19, 2013 at 7:34 pm
Hello! Sweet scale design! I plan on making one, with a better scale with a higher capacity. Also beef up the prying tougnes with thicker stock. I am thinking of sandwiching the pry tougnes with another layer of 3/4″ plywood. Or maybe make it out of solid aluminum stock. Any suggestions? Thanks
December 17, 2012 at 4:10 pm
Doug,
“Tom Rearick at Beehacker.com” is fine. Thanks.
December 17, 2012 at 2:41 pm
Thanks for the great design! I’m currently constructing 20-30 hive scales for use in a research project at Ohio State University. I would like to attribute the design to you–how would you prefer that I do that?
Doug
January 5, 2012 at 6:18 pm
That is a good point. I suppose the more important time to actually be concerned about the weight would be winter anyway when you would want to make sure they haven’t depleted their food supplies without needing to open the hive up.
January 4, 2012 at 3:49 pm
The paddle is roughly 6 inches wide and 18 inches long though it might work even better if 24 inches long because you get more leverage. The dimensions are not as important as the tongues’ stiffness (bending causes inaccurate measurements) and having a long enough handle to provide some leverage (even half a hive gets heavy).
Please send us a picture if you build it, ok?
January 3, 2012 at 8:53 pm
What are the dimensions for the wood?
Thanks
January 2, 2012 at 10:55 pm
Adam, Good question. First of all, at least one hive body is going to contain a fair amount of brood and pollen which is a lot lighter than honey. And even if a hive body is all honey, it is not necessarily full. But your point is well taken – in a really good year, the scale will max out. My hive #1 did max out at 160 pounds this year with two hive bodies and (I think) a shallow super. You can see this flat line on the apiary chart. But at that point, I don’t care…I know the girls are doing well and I can harvest as soon as the flow is over. Most of your bee problems will be with the weak hives that never top out.
January 2, 2012 at 6:23 pm
So I’m a little confused. If each deep super can way up to 100 lbs and each medium super up to 70 lbs, with two deeps on the hive at all times that is 200lbs and then with the addition of a single medium super the weight of the hive easily outweighs the 250lb weighing capabilities of the device. Any thoughts?
September 22, 2011 at 9:54 am
Here is someone who has hacked together a scale for under $50:
http://makingthingswork.wordpress.com/2011/09/15/70/
December 31, 2010 at 8:07 am
Beyond the traditional heft method I have in the past used a digital fish scale for estimating the weight of a hive. I acquired the essentials for the heft method from a couple of old commercial beekeepers and implemented this ‘wisdom’ several thousand times just to make the lesson stick. The essential ingredients of the digital fish scale was obtained from a old (1970ish) bee journal written by a fellow who taught physics at a college not so far from where I first began beekeeping. The digital fish scale and the portable hive scale appear to work on the same idea. There is some critical information lost (defined quite clearly by the author of that article so long ago) of the portable hive scale described in this thread.
December 9, 2010 at 12:08 pm
Hi,
I use a bathroom scale at the bottom of one of my hives. It is an old fashioned analog scale (the digital scales turn off after a while so they do not work).
I made a frame and fitted the scale into it upside down. It stays there and I read the weight of the hive with the help of a mirror. This way I keep a continuous eye on the weight of that specific hive. I wrap a transparent nylon bag around so bugs do not start invading my scale (they have done it before). When the nectar starts flowing, I read the increase in weight of that hive. I assume all the hives at the same apiary follow more or less the same weight development.
In Norway, there is a project of weighing sample hives all through the country. You find the sample hive nearest your apiary and follow the weight development via the internet. If you also weigh your own hives, you can make a comparison.
Cheers
Kamil
November 26, 2010 at 12:38 pm
I get it but I’m not sure I would trade scales with you. Your approach is simpler but is it more convenient and accurate?
If your scale is not perfectly in the middle of the 2×4, there will be leverage which means that the bathroom scale is not reading (half) the hives weight. How repeatable are the results of this simpler scale? Did you actually build this thing or is it thought experiment? How do you read the scale while levitating the hive? I would love to be able to post a picture of it in action.
November 25, 2010 at 2:13 pm
Holy smokes, you sure made the “pry scale” complicated. This is what I have been doing for years to weigh my hives; use a 2×4 of any length; put a fulcrum right in the middle; put bathroom scales under the fulcrum; push down on the end of the 2×4 until the hive bottom board just breaks a crack from the stand – the weight you read on the bathroom scales is the weight of the hive. Get it?