Yes, grinding motor noise
hello all,
yes, a grinding motor noise (and NO, it is not caused by not having the separator cleaned). Started by this thread I took the effort to get hold of a Rainbow, a D-series model that is. It does NOT have this sound.
It sounds just like any regular vacuum (it has a normal 800 W carbon brush motor). And it cleans like any regular tank-type vacuum. Thanks Diana for letting me use it for a bit ;-) Nice thing! Carbon brush motor type, how nice.
Yet I've seen some on youtube (E series) that were declared to be reluctance motor ones. THERE! The nerve-wrecking sound when ramping up. This strange grumbling howl, this shrill yet grinding noise,a strange magnetic hum going upwards, kind of a dentist's drill dubbed with some transformer hum, I cannot really explain. Yet when on full speed it is (almost) ok, but somewhat strange roaring remains to be heard.
It must have to do with the new electronic motors, the reluctance type. I have found the same sound on Vorwerk VK 140, on their latest kitchen blender TM 31, on the Black & Decker "el cheapo" wannabe cyclone vac D2000 and on the later E2 series Rainbow vac.
It drives me nuts, I cannot even figure out why it does. Each time the info says "reluctance" motor. Goodness, if I could just get the same units featuring a regular brush-type motor...
I fear that more and more vacs are going to be reluctance motor type, so that will be it for me with collecting vacs, this strange and very disturbing sound drives me nuts.
Why can't something of the new direct-drive washer motors be adopted, just some coils and just some solid-state electronics to control the speed? (Ok, I can hear the tough ones again: "this is just the same" - no it is not, the reluctance motors (apart from having a lower electrical efficiancy compared to standard motors) they have this strange growl to them, the frequency controlled washer motors just don't).
Anyway: A good vac sounds low-hummed, air-rushing and strong to me, but not loud or shrill or strange.
