Uploaded March 2022 | Updated September 2026, 1 week ago
I freely admit to being a mechanical engineer that has no right to be dabbling in the well researched 3000 year old science of lenses. I keep being told by those well versed in this subject that the smallest focal diameter will be achieved when I use the maximum diameter of lens available. In my case that means expanding a naked 3 mm 30 watt output beam by at least a factor of 4. I can fully understand how and why this works just fine for creating a concentrated focal spot for engraving but my experimental work and vandalism of lenses indicates that an engraving focus is not a cutting focus. Thus I am fascinated by the very small very high intensity beam I have managed to project into the central area of my worktable. Previous quick exploratory tests indicate that there is a very weird relationship between this very small beam and lenses. In this session I try to examine that relationship in more detail with several comparative experiments.
I freely admit to being a mechanical engineer that has no right to be dabbling in the well researched 3000 year old science of lenses. I keep being told by those well versed in this subject that the smallest focal diameter will be achieved when I use the maximum diameter of lens available. In my case that means expanding a naked 3 mm 30 watt output beam by at least a factor of 4. I can fully understand how and why this works just fine for creating a concentrated focal spot for engraving but my experimental work and vandalism of lenses indicates that an engraving focus is not a cutting focus. Thus I am fascinated by the very small very high intensity beam I have managed to project into the central area of my worktable. Previous quick exploratory tests indicate that there is a very weird relationship between this very small beam and lenses. In this session I try to examine that relationship in more detail with several comparative experiments.
