Dirt

[brassnut]

Where dose the dirt and dust come folks.

[jhb171achill]

You'd wonder, wouldn't you!

A light dust sheet can be helpful if it doesn't risk damaging delicate scenic details.

[Broithe]

Fibres from clothes, curtains, furnishings, etc., and some bits of skin.

 

Running your railway naked after a good, hot, exfoliant shower might help.

[patrick]

Since the motor is part of the bogie on that model static electricity may attract fibers. Too much oil on the gears and running the model on track on the floor wouldn't help either.

[David Holman]

A lot of skin - it makes up the majority of household dust. That looks like several years of not being used, while are the middle wheels missing their treads? Fairly horrible & crude flanges by the look of them & are they traction tyre or is that rust on the wheel treads? Either way, cleanliness before Godliness where model railways are concerned - track, wheels and mechanisms. There is absolutely no substitute if you want good running.