Modeling closed loop kinematic chains can be a bit difficult. VC has helper functions called sasa-functions that help you solve mechanisms that form a triangle or a quadrilateral. Those functions require you to measure the triangle or quadrilateral effectively and for that I have created this add-on called SasaHelper.
To use the add-on unzip it under your Documents\Visual Components\4.X\My Commands -folder. Add-on will add two buttons on Modeling tab. Sasa Helper is used for solving triangles and Sasssa Helper is for quadrilaters. Launch the add, select a plane where your triangle/quadrilateral needs to be solved in and then select 3/4 corner points on the 3D model. Add-on prints side lengths and corner angles and pre-filled sasa-functions that you can copy-paste as your follower joint expression and make some modifications on them to create a functional follower.
I will post a link to a tutorial video on how this add-on is used. Add-on package contains two test models on which you can try it out.
SasaHelper.zip (131.5 KB)