Specifically, I lay out a line constrained to north by an angle constraint, and an angle constraint. Then, I add an arc and tangentially constrain it to the end of the line. From there, I want to fully-constrain the arc. I apply a radius constraint, leaving only one degree of freedom - the far end of the arc.
In order to constrain the arc's end point, I would typically apply an angle constraint to the arc (defining it's central angle). or possibly set it's chord length (half the straight-line distance between the curve end points). This is typically how curves are defined in transportation engineering.
However, if I try to set an angle constraint to the arc, or apply a length constraint between the arc's end points, Sketcher tells me it's invalid. It seems like this is a sketcher bug...
In the image, the angle constraint should read 48 deg, 48 M, 34 S (48.8094 degrees), and the doubled chord length (the total straight-line distance between the endpoints) should be 833.54758.
EDIT: I can fix the arc endpoint using a fixed constraint that ties it to the origin...
Code: Select all
OS: Windows 7 Word size of OS: 64-bit Word size of FreeCAD: 64-bit Version: 0.18.15340 (Git) Build type: Release Branch: master Hash: 14b780c0ee9a0cd4adc2dc7abdff94ed315dd781 Python version: 3.6.6 Qt version: 5.6.2 Coin version: 4.0.0a OCC version: 7.3.0 Locale: English/UnitedStates (en_US)