FreeCAD: Arc / Arch Length. How to use a spreadsheet to constrain a sketch and a macro to measure

We will explore how to create a spreadsheet and use it to constrain your sketch in FreeCAD sketcher workbench. The video answers a viewers question in how to constrain an arc by its length and how to measure it by clicking on the arc in the part. We will first create a spreadsheet and use a formula to constrain the arc and reference this in our sketch. As constraining by length requires two parameters then the constraint has to be calculated. We will then venture into measuring a arc length offering two ways of doing this. We will learn how to write some basic python code as a macro, attach this to a button and place the button on a toolbar so it is always available. The other way is to use a ready made tool available from the curves workbench. (See bottom of text for Macro) , , Journey with me and Patreon Donate: Subscribe: Browse my Redbubble Shop: Macro for measuring: FreeCAD.Console.PrintMessage("n") FreeCAD.Console.PrintMessage(Gui.Selection.getSelectionEx()[0].SubObjects[0].Length)