I have developed in OpenSCAD a geometry simulation of delta robots.
It runs on the last version of OpenSCAD (the development snapshot) that you could find here
It allow to test any geometry of a parallel column delta robot and validate travels and conflicts.
This simulator can be found here https://github.com/PRouzeau/OpenSCAD-Delta-Simulator.
You are invited to carefully read the instructions, both at the start of the SCAD program and in separated files.
This simulator engine was the core of the more developed simulation of my own delta design Lily and Lily Big.