To repeat, a lot of original material disappears from the internet over time and only echoes of this nature remain. It's all consistent though, from multiple independent sources. There's no good grounds to not be reasonably convinced by this. If you're still not happy with that, then you're stuck with the dilema of explaining why you're happy with the original claim associated with the 1940s cyclone being implied to be the same as Dyson's cyclonic achievement, which has absolutely *zero* evidence in support of it. Slight disparity there you're ignoring. Figures...
Incidentally, predicting you're still living in denial, I'll just mention a few things about Newcombe's separator. The early air-based one from the late 1920s has sketchy records, but you can estimate its effective cutpoint size at around 15–20 µm (size of dirt and lint) from the technology of the time (see later), which is wholly inadequate to not need bags or avoid heavy air pollution.
The later water-based separator bubbled dust-laden air through a cyclonic water vortex, using centrifugal force to fling particles into the water film. This impractical hybrid design by today's standards captured coarser particles effectively but struggled with fines due to re-entrainment in the wet vortex and lower centrifugal forces (estimated 500–1,000 g, vs. Dyson's 150,000 g—see below). No original efficiency curves survive, because I've checked, unlike my failed attempts to successfully get you lot to adequately above, but 1920s patents emphasize "coarse dust removal" without quantifying fines. I'll leave you to fact-check this for yourself—it's fairly straight forward because I did it myself in all of 2 minutes.
Furthermore, you can even estimate from the simplified Lapple equation for cyclone cut point based on 1920s technology (cyclone diameter ~0.2 m, effective turns ~5–10, particle density 2,500 kg/m³ for dust, and inlet velocity ~15 m/s [from estimates of 1,000–5,000 RPM for 1920s motors]) that the cut point is about 12–18 µm, and marginally better than the original cyclonic separator. This is still over an order of magnitude inferior to what is needed to act as a fine dust primary dirt separator—i.e. not reliant on bags or risk causing heavy air pollution or rapid filter clogging. This is apples to oranges. Again and again, despite all the evidence, you deny what Dyson did was fundamentally technologically different, despite that they built on the foundational historical designs. They achieved, for the first time, true adequate primary dirt separation of micron scale particles that affect health, entirely inertially without primary reliance on mechanical separation or dealing with scummy water tanks. I think most readers can get this by now, even if you are unable to.
This also has nothing to do with stick vacs, i.e. the thread topic...
