The simplest way to measure an inside radius involves using a straight edge and, ideally, a framing square for increased accuracy.
Here's a breakdown of the process:
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Gather Your Tools: You'll need a straight edge (like a ruler or level) and, for more accurate results, a framing square.
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Position the Straight Edge: Place the straight edge across the opening of the inside radius, forming a chord. Ensure the straight edge makes contact with both edges of the radius.
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Measure the Chord: Measure the distance between the two points where the straight edge touches the radius. This is the chord length.
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(Using a Framing Square - Optional but Recommended): The framing square helps ensure your measurement is taken at the widest point of the opening. Place one leg of the framing square along one edge of the radius. Position the straight edge along the other edge of the radius, ensuring it's perpendicular to the first leg. Now, measure the chord length using the straight edge.
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Calculate the Radius: While the video excerpt doesn't explicitly provide the calculation, you would typically use the chord length and the depth (the distance from the center of the chord to the arc) to calculate the radius using a formula or online calculator. A common formula is:
Radius = (Chord Length2 / (8 * Depth)) + (Depth / 2)
Where Depth is the perpendicular distance from the middle of the chord to the edge of the arc. Note that the depth wasn't directly mentioned in the excerpt, but it's crucial for calculating the radius. You'll need to measure the depth to complete the calculation.
In summary: Measuring an inside radius accurately requires a straight edge, and optimally, a framing square. Measure the chord length across the opening, and then use that measurement (along with the depth of the arc) in a formula to calculate the radius.
