The Spine tester I have been using is from Primitive Archer magazine volume 3 issue 3. This is basically the same as the article, but written from my perspective. This spine tester is very easy to make and use. It will require very few tools and supplies to make it and can be made just about by anyone. The supplies and tools I have listed below.

     This picture is the best I have for now. It is hard to see but there is a nail about 1" to the left of the red piece of lead. This arrow shaft has a spine of 28 degrees but it is hard to see by this picture. I hope this helps until I get a better picture.

Tools:

Standard cross-cut saw
drill
Screw driver

Supplies:

Lumber
screws
360 degree protector
2 lbs. of lead
1 small nail
1 Screw eyelet
Glue
Cardboard
1 Penny

      The most important part about this spine tester setup is the distance between the upright rods and the placement of the protractor. To begin you need one piece of lumber flat with 2  pieces screwed to it to form two upright board that are 26" apart. Both of these board will need groves cut into them for the arrow to rest but wait for everything else to be finished so they line up with the protractor. Now you will need to drill two holes in your protractor, 1 at dead center and 1 at 1" to the left of center. Use the one that is 1" left of center and glue the small nail into it and glue the penny to the far end of the protractor as counter balance. now you will need to cut the cardboard to be about 1" wide and about 2" longer than the diameter of the protractor. You will need to draw a line down the long center of the cardboard and drill or cut a hole at dead center of the line you just drew. Now you will need to cut and mount another piece of wood to the back of the wood already assembled so that is standing upright, slightly taller that the last uprights and is 1" to the right of center of the assembled boards. Now mount the protractor by running screw through protractor then through cardboard and into the wood. Tighten down so it looks tight but protractor  and cardboard can still spin freely. When the nail, center hole and penny are all horizontal they should line up with where the bottom of the groves you need to cut for the outside uprights. Now you can take a rat tail file and cut the grooves for the arrow until the protractor lines up horizontal with the arrow in place. You will now need to melt the lead into a usable form. I put mine in an old Tuna fish can and melted it on the gas stove. Then when cooled, I cut the can away with tin snips and painted the lead. (The lead will rub off on your hands while handling if not painted and is not good for you.) Then the eyelet will need to be opened up to form a hook and will need to be screwed into the lead block so it can be hung from the arrow. I liked the Tuna can because it made a very thin 2 lbs. blank which does not get in the way.

       Now to use it just put the arrow on with the nail under it and line the cardboard up so that the line is at 0, 90 or some other degree mark to get your reference. Now hold the cardboard still and hang the weight near the nail and measure the angle of deflection on the protector in degrees. Use the chart I have converted to degrees below to get your spine reading.

My spine chart converted from the authors co-sine chart to degrees on the protractor

Pounds             26"                27"                 28"                   29"                 30"

30-35             59-90           49-59             41-49               35-41           31.5-35.5
35-40             49-59           41-49             35-41            31.5-35.5         28-31.5
40-45             41-49           35-41           31.5-35.5         28-31.5           25.5-28
45-50             35-41         31.5-35.5        28-31.5           25.5-28          23.5-25.5
50-55          31.5-35.5        28-31.5         25.5-28          23.5-25.5         22-23.5
55-60            28-31.5         25.5-28        23.5-25.5         22-23.5            21-22
60-65            25.5-28        23.5-25.5       22-23.5            21-22
65-70          23.5-25.5        22-23.5           21-22
70-75            22-23.5          21-22
75-80             21-22