Pry scale, part III

I thought I had it working this time.
I disassembled the T-shaped pry scale and reassembled the first model, this time with broader pry bars.  This necessitated drilling a couple of more holes in the wood and through the metal bars.

I cut a notch into the dowel that holds the scale to keep the scale from slipping.

Next, I had to provide a rigid lifting bar.  I looked into my odd and ends and found some metal shelf racks.  I cut them to 16-1/4 inches (the width of the hive) and cut a notch in the center wide enough for the pry bars.

Unfortunately, the notch made the bar too flexible.  Fortunately I had the narrow metal strips from the first iteration.

This made the bars unbendable....at least in vitro.  I removed the shims from under the hives and put the lifting bar in place.
Now for the test:  it sort of worked.  There was still some give in the lifting bar.  I had to press the lever to its limit to lift the hive and the hinged piece hit the pulley.  This gave an inaccurate weight of the hive.
I tried putting a screw below the lever to limit its downward arc, but this did not solve the problem of the flexing lifting bars.
I have more ideas.  Stay tuned for the further adventures of Pry scale- part IV.

Pry scale, part II

I came up with a few options on how to solve the problem:  I could re-enforce the strip of wood that was flexing or I could lift from the sides of the hive that are already rigid.

I could not think of an easy way to re-enforce the wood strip, so opted for lifting at the sides.  Of course, the force of lifting had to be down, against the hive stand, not up against the flexible wood.  I wanted the lever to be on top, so this entailed a couple of more pulleys to redirect the force on the hinged middle bar.

Plans for second pry scale attempt

The shims needed to be moved laterally to make room for the lifters.  The side rails of the hive are only 3/4 inches wide, so I had to be careful giving enough space for the lifters.  Another trip to the hardware stores for more pulleys and stronger metal strips for lifting.
A bit more time in the garage sawing, drilling, adjusting, et voila!, a new pry scale.

The pulleys underneath

Off to the hives for a field test.....Failed!  The thing just did not lift the hives.  It may be that this special non-stretching sailing line actually stretches too much or that the lifting bars are not strong enough or some other malfunction.
This is becoming my great white whale.
Stay tuned for Pry scale, part III

Pry scale, part I

There are many reasons to follow the weight of the hive.  Basically, it is a simple way to monitor the health and activity of the hive. There are also a multitude of ways to do it, from low tech, such as lifting the hive onto a freight scale, to high tech electronic devices.  And then, of course, is the multitude of homemade devices.  I would have liked a fancy, easy to use electronic device but could not justify the expense.  I decided to make a pry scale.  I used this blog and this YouTube as my guidelines.  Of course, my hives' set-up is not the same as others and the lifters needed to be longer.  These are my detailed plans.

The parts were assembled by means of a few trips to three different hardware stores as well as digging through my collection of wood scraps and nuts and bolts.  I got the Dyneema string at West Marine, where I was not charged because I had had to wait way too long.  I got the scale on line.
Then to build it.  First, without measuring, I used one of the hinges to determine the size of the hinged piece and cut it out of an old cutting board.  The pulley was a clothes line pulley and I had to drill and punch out the plastic bracket.  The angle braces had to be far enough apart to allow the hinged piece to move so I made spaces with flat plumbing washers and some sort of ferrules I had from a long forgotten job.

Then I laid out the pieces on an old cutting board and marked where to drill holes for the bolts.  I used the drill press I got from my father.  I also had to drill extra holes through the hinges for the lift bars.
Here is the finished product:

The lifting bars required a space between the frame and the stand which I accomplished with 1/4 inch shims cut from another scrap of wood.

Shim in place

Space for lifting bars

Now for the test........
Pry scale fail!
The device worked, however the piece of wood above the space is not rigid enough and would flex and the lift bars were not strong enough and also bent.  Back to the drawing board. 
Stay tuned for Pry Scale, Part II.