If you’ve ever used Excel to present data with ‘holes’ in it, you might have been frustrated by the options for how those holes should be represented on a chart. Here’s a short summary of one way to make the holes show up as missing data points rather than ‘0’, which might be confusing, inaccurate,…

Belleville Springs (aka “Belleville Washers”, “Spring Washers”, or “Disk Springs”) are wonderfully useful mechanical devices, but with one minor drawback – their properties are difficult to calculate – until now!  Almen and Laszlo were the first to develop a workable calculation method, but it can only loosely be described as “workable.”  (This is the method…

Happy 4th of July Everybody! When in the course of human events it becomes necessary to calculate the Darcy-Weisbach friction factor… engineer’s often throw up their hands, go back to their old college textbooks, and say “about .02!” [Which normally isn’t off by more than a factor of 2 in either direction.] If you want…