The Kato Ge 4/4 III whine

[Welshbloke]

Or maybe a growl. Either way, if you have one of these you've probably noticed that it's blinking noisy compared to other Kato stock. I have two, the second of which produces an annoying growl/whine when running at a scale speed. My Allegra, Ge 4/4 II and the other Ge 4/4 III are also noisy but nothing like as bad.

 

So far I've narrowed the problem down to the motor, specifically the brushes/commutator interface. I tried my usual trick to flush out any carbon (washing up liquid, rotate by hand then flush with clean water). The noise disappeared...until the motor fully dried out at which point it returned! At the moment I'm trying a long run at speed to see if that will bed the components in and stop the noise.

 

The brushes don't appear to be removable so I can't really investigate further, but would be interested to hear if anyone else has. It's an annoying flaw in what's otherwise a very lovely range of Swiss metre gauge stock. I can't see the motors for sale separately either, just complete chassis minus bogies.

[AllScales]

But it gives you a sound feature at a budget price!

[Gryphr]

Does it have the 3 pole motor? Several of my recent (new) Kato models with that motor, mostly MU's, are also quite "whiny". I wonder if they changed anything about the motors/production which causes this.

[Welshbloke]

It may well be, I can't see the commutator that well. It feels slightly lumpy when turned by hand, as if the edges of the commutator segments need bevelling for a smooth transition between them. It looks as if the brush holders are pressed in with the brushes, trying to remove them is likely to make it worse. The older motors had clip on caps holding the brush and spring inside the guide tube, so you could strip and clean motors to remove carbon.

 

My E231 has a similar whine but not quite as bad. The KuMoHa 11 and 12 units have it but on those wedging a slice of rubber band either side of the motor seems to have brought it down to reasonable levels. Tried that and some thin foam on the Ge 4/4 III to no avail!