From WoodworkersZone WoodWiki
No Math Measuring!
One common mistake that new woodworkers make is to over-rely on their tape measures or rulers. While these tools do just fine for house construction, most just don't have the accuracy or precision that you'll want for your woodworking projects.
Suppose you're making a chest of drawers, and you want your drawer fronts to fit in the opening snugly with little gap. Also let's say that the opening just happens to be 16 13/32nd” wide. Trying to use your tape measure to get an accurate size on the opening is going to be frustrating.
Experienced woodworkers have a saying “The best way to measure something is not to measure at all.” What they mean is to simply hold your drawer front stock up to the opening and make pencil marks on the stock where the cuts need to go.
- Save your tape measures for rough dimensioning. And, if you do use one, be sure to use the same one through-out the entire project.
- Minimize fence movements. Plan your cuts ahead of time, so you can cut the same sized pieces all at once. It is very difficult to cut two boards to the same width, if the fence moves in-between the cuts.
- That little metal hook on the end of the tape measure is supposed to be loose – don't tighten those rivets. The play in the hook should equal the thickness of the hook. The hook should slide in for inside measurements, and slide out for outside measurements.
The Story Stick
A story stick is simply a piece of scrap stock with a the dimensions penciled on it. It tells the story of your work piece. A story stick is easier that remembering or transcribing measurements; its more accurate; and it doesn't care if one measurements is 11 11/64”.
Another approach is to use stair buttons on a rule. They make it easy to reproduce measurements.
Finding The Center
The best tip of all is: learn to do without your tape measure. Train your eye for finding the center of a board. You can quickly find the center of any board, without math, by using a scrap piece and a pencil.
First – align the left edge of the scrap and the stock. Second, take your best guess at the center and draw a line on both scrap and stock.
Third – side the scrap over to the right until the mark on the scrap lines up with the right edge of the piece. Finally – split the difference between the line on the stock and the left edge of the scrap. That's the center of the board.
Dividing Stock Equally
Dividing a board into equal slices is easy with just a ruler. And there's no math involved here either. You just need a ruler long enough.
To rip any width board into four equal pieces, lay your rule across the piece with the 1” inch mark on one edge and the 5” mark on the other edge. Make three lines at 2, 3 and 4”.
To cut a board into thirds – place the 1” mark on one edge, the 7” mark on the other – and mark your cut marks at 3” and 5”.
- Your finger tip is amazingly sensitive – and can easily detect a difference of 0.001”. Use your finger tips to align edges and feel for misalignment.
- A penny is about 1/16” in thickness and is great for sizing the gaps around a door and the frame.
- using two ripped offcuts from a milled board and a spring clamp, or more if it's a long opening, you can get the exact inside dimension -- just extend the two pieces until they're squarely against each edge and apply the spring clamp near the middle. Take the pieces out and transfer the size to your story stick. Now, you know how large the Inside Dimension needs to be. Easier and more accurate than trying to extend a tape measure inside the opening and then adding 2-3/4".