Speedy Layout With a Calculator

I use a Construction Master Pro calculator to lay out everything, at least everything I can. It’s the only way to ensure quick, precise layouts on the first try. For both the spindle railing and the lower balustrade, I first decided on the end spacing — the distance between the last baluster and the newel post. Jed Dixon, a stair specialist in Rhode Island, once explained to me that those spaces appear best if they’re about half the distance of the on-center spacing. So we chose 2 inches for the spindle railing (4 inches on-center) and 2 1/2 inches for the lower balusters (5 inches on-center).After marking off those measurements, I measured the intervening distance and divided that number by 4 inches for the spindle railing and 5 inches for the balustrade. Of course, the quotient always included a whole number and an odd fraction: For instance, a 102 3/8-inch run divided by 4 inches equals 25 5/8 inches. I rounded the fraction up if it was well above 1/2 inch and down if it was close to or below 1/2 inch, then divided the distance by the resulting sum. With that many spindles, it was safe to round the number down if the fraction was close to or below 1/2 inch. For instance, 102 3/8 inches divided by 26 equals 3 15/16 inches, whereas the same distance divided by 25 would save one $25 spindle and the spacing would be only 1/8 inch more than 4 inches.

But a CMP is even more useful when it comes to marking the layout for each spindle. Stretch a tape measure down the railing. First divide the distance by the number of spindles and press the = button to arrive at the spacing between the center of the first spindle and the center of the second spindle. Then, simply press the + button once, then the = button again. That sum is the exact center of the third spindle. Now press the = sign again and the CMP will calculate the exact center of the fourth spindle. And I mean exact: The calculator remembers all fractional sums less than 1/16 inch (you can program the calculator to work in almost any fractional increment, but I prefer 1/16), so it’s always adding the fractional increment whenever it exceeds 1/16.