This is the main engine part. Costs almost as much as a whole Dyson, and they are not commonly available on the web! Still, it has a good huge engine, and a gravity-catch type dust collector, but a cloth final filter that is "shaken" by weights every time the power cycles to keep it clean and feed the dust into the same collector as collects the larger objects.
You can see the 2.5 inch pipe that leads throughout the house:
It is dark gray except for the bit I added.
The thing uses so much power, as does the washing machine,
that the circuit breaker trips if the washer tries to start up
while the vacuum is on. This is mainly because cheap washing machines
have huge startup currents in 110V-land.
The vacuum points throughout the house were a delight, because
of their original 1960s design, a sort of "electrical art-deco",
reminiscent of Flash Gordon.
I rewired this one with a modern switch (the old system reuired
a momentary contact, new machines have a low-voltage make-to-run
This one I wired with a microswitch, so that the engine starts as the
hatch is pulled open.
You can see the nickel-plated hex-bolts holding the microswitch behind the cover-plate
The old white button remains, but has no function.
By comparison, this is a modern plastic one.
I used this in the main hall upstairs, because
it seemed to require an inconspicuous, wall-colored plate.
It is neither as easy to use nor as charming as the original units!
Ironically I write this as I check the website before we put the house on the market. The very first of our many improvements was to be documented last of all.