Although you can get away with using a cheap plastic ruler for an occasional pinewood derby car, having a nice, accurate rule (not ruler) is a must for any serious craftsman. But like any tool, there is a large variety of rules available on the market. Today, I want to share with you my favorite rule. In my opinion, this rule is a must have for pinewood derby enthusiasts.
The rule I am referring to is the Incra Six Inch Precision Bend Rule. Although this rule wasn’t specifically designed for pinewood derby use, I have to believe that the designer was a pinewood derby parent.
Incra Six Inch Bend Rule
The obvious feature of the Incra Bend Rule is the shape. The rule is specifically designed to fit over the edge of a block or board in order to make precise measurement with ease. The rule is marked in 1/32 inch increments, and at each increment is a hole and a slot that allows insertion of a 5mm pencil (standard mechanical pencil size). These holes and slots eliminate the inaccuracy that comes with trying to make a pencil mark along the side of a regular ruler.
Making a Measurement
This feature in itself makes this a nice tool, but there’s more. On one end of the Incra Bend Rule you will find measurements that are perpendicular to the rule. These are used to mark offsets from the edge of a block. For pinewood derby cars, the obvious use is marking axle locations, weight hole positions, car thickness, etc.
Marking a 1/8 inch Offset for Axle Holes
But this offset measurement feature is not just to make a tiny dot, but it can also be used for drawing horizontal lines. Just insert the pencil at the desired location, and slide the rule along the edge of the block. Sweet!
Drawing a Horizontal Line
Now the “pièce de résistance”. Do you want to locate the center of your block? One half of the Incra Bend Rule is 3/4 inch wide, while the other is 7/8 inch wide. 7/8 inch is a familiar number – it is one-half of the width of a standard block. So to find the center of a block, lay the rule with the wide portion on the top or bottom of the block, and strike a line. Since blocks are not consistent, put the rule on the other side, and draw another line. “Voilà!” The center of the block will be between the two lines (or coincident with the two lines if the block is exactly 1-3/4 inches wide).
Photos 5 & 6
Finding the Center of the Block
I am confident that you will enjoy this rule as much as I do. This rule is available at some specialty wood stores, but to save you the trouble of tracking one down, Maximum Velocity is now offering the Incra 6 inch Precision Bend Rule. You can find it on our web site Here
From Pinewood Derby Times Volume 9, Issue 4
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