No need to run them in now, then. The manufacturer should have done that in the first place! Don't people know anything these days?

No when they is from Manchestoor

They have brushes on there motors still for suction pumps? I thought they went out with the Arc, sorry Noah.

Brushless!

Cost!

It may not have been brushes (I can't remember my commutators from my squirrel cages these days nevermind B vs phi graphs!), it was all the materials in the pump were new and stiff and needed a good old run-in like an old motor car. Not had a problem since and the company ensure they are run on and off load before giving them the ok to be sold

It could also have been, of course, "ingress" of all sorts of unmentionable er, debris!

I would expect a universal motor (that is, a series-wound commutator type) in most low-end mains-powered suction pumps, by the way. But I guess that, in this thread, we are basically talking about simple battery-powered portable suctions units. And therefore, simple DC motors, with commutators and brushes.

Brushless DC motors are around, of course (you find them, for instance, in 3.5" floppy disk drives) ... and they are essentially permanent magnet AC motors. But they require the added "complication" (read as cost) of the controller circuitry.

But (just in case there's anyone reading who hasn't already noticed), where the brushless DC motor has really "taken off" is in the realm of flying model aircraft (yes, that was a pun)!

you must have gone to those lectures with the chaps from GEC that I "missed"

What's that ... the one about debris?

I can't remember the last time I attended a lecture. But it must have been something like thirty years ago!

It's just that I'm interested in motors ...

... also:-

Anaesthetic Agents
Batteries
BlueTooth
Computer Code
Disk Drives
IDE
EPROM's
Filters
FireWire
Fuses
Lamps
Lubricants
Medical Gases
Membranes
Memory Cards
Operating Systems
PCI
Pumps
SCSI
USB
Wi-Fi
X-Ray Tubes ... etc., etc., etc.

Just music, beer and motorbikes for me now