It was intuitively obvious to me that accurate screw mapping depended on knowing my location on the screw accurately. To my surprise, once I reasoned it out, I found that this is not the case. I include a mathematical proof.
Please do not confuse position during screw mapping with using this mapping. Errors in Home directly affect knowing actual position.
If you are interested, please see
Your comments are welcome. All of us are smarter than any one of us.