Back in the day ... before mobile phones, tablets, computers and even hand calculators people invented amazing devices to aid in mathematics and calculations. In fact, many of these devices are still in use in some industries today because they are still as fast and as accurate and anything invented since then.
One of the items that fits this category is something called the Lumber Rule. They are still being manufactured today, though in much smaller quantities. The only real disadvantage of a lumber rule is that anyone who uses one is probably also carrying around a smart phone, which ... will do the same thing, kind-of, though often slower, and the smartphone still needs a tape measure to go with it.
I have seen these Lumber Rules listed on a different auction sites, for some pretty serious money, I guess anything that is perceived to be "old" must be expensive (???) So I decided to make my own version of a lumber rule to help me quickly figure out the board feet contained in a board so that I can know how much that board is worth.
If you are at the lumber store and are only buying one of 2 boards, or some small quantity, who cares? ... a smartphone, or even just a tape measure will work fine. IF - however you are buying a quantity of boards, or you are wanting to compare prices of different species in the lumber store, and do it quickly - nothing will beat a Lumber Rule for accuracy and speed.
Lets stop for a moment to review what a board foot actually is ... a one inch thick board, 12 inches by 12 inches.
But lumber is shown in feet and inches ... for example a 8 foot board, 1 inch thick and 6 inches wide contains 4 board feet. To get this you need to convert everything to inches first of all so ... 8X12 = 96"x6"x1"=576 square inches. NOW ... that needs to be divided by 144 (12x12=144) so, 576' / 144" = 4 board feet.
And that's why a simple hand calculator is slow, too many numbers to crunch each time. A smartphone is faster with a board-food app installed, but you still have to type the numbers in each time ... if you can even read the tiny fonts they are using when you are in the lumber store which is often poorly, if even lit at all. And that's where a lumber rule can become an instant friend, simple to make and accurate every time, at least if you put the right numbers in the right spots.
You can figure out all the numbers for the scale on your ruler yourself, or you can do what I did and go to the Internet and look up "board foot chart" or something similar and you will have many different ones to choose from. You may also find something called a "Log Scale" you don't want this, your want a lumber scale or board foot scale.
I made mine double sided so that no matter which hand I am using, I can read off the number of board feet quickly. I made mine about 20 inches long but I can see that one that is only 10 inches long would work fine too. The video explains how to make and use the Lumber Rule and if you have some way of marking the numbers on nicely, instead of using a felt pen like I did, you could make yourself a real gem of a tool. Mine is another utility tool, not pretty, but quick and effective and I know the next time I am at the lumber store and comparing different species for cost, I will have my lumber rule along so that I can quickly compare prices of different boards to get the best value and usage out of the number of board feet I will need.
Copyright - Colin Knecht