Mamod twin cylinder SE3 steam to electricity

At Cubs we are doing the scientist badge as an extra show and tell I brought along my dads Mamod S.E.3 Steam Engine and hooked a 9v motor to the buffing wheel via an elastic band.   It managed to make the led light up and impress the cubs. Before I use it again i need to make a mount for the motor so the band dose not fly off every time you try and take a photo/video.