I've had one of these for years!
From memory - there is a plastic 'sound box' inside the tender and an arm which hangs down to the rear axle. The end of this arm is coated with a 'sandpaper' like substance. Around the rear axle is a metal (copper?) clip, part of which extends slightly and scrapes against the 'sandpaper' arm causing the 'chuff chuff' sound to be made.
I don't remember the 'arm' being copper coloured (thought it was black) but I may be wrong.
Have found a copy of the original loco service sheet online but the tender is not included.
Will have another look when I get home later!
From memory - there is a plastic 'sound box' inside the tender and an arm which hangs down to the rear axle. The end of this arm is coated with a 'sandpaper' like substance. Around the rear axle is a metal (copper?) clip, part of which extends slightly and scrapes against the 'sandpaper' arm causing the 'chuff chuff' sound to be made.
I don't remember the 'arm' being copper coloured (thought it was black) but I may be wrong.
Have found a copy of the original loco service sheet online but the tender is not included.
Will have another look when I get home later!