Big Ada.. its nothing than that of some plastic gears.. here i am adding the photograph.. hope can understand.. also add a video of internal.. i used a big gear, and a pillion for it, nothing about serious here as ratios.. just all from scraps.. and used a brass tube as outer tube, then inserted the drive shaft through it that you can see in earlier photographs, and the tip of the spoke, is feded with a brush less motor, one is driven in with a nipple of bicycle spoke nipple, as a coupler, this shaft passes through a second inner tube, that the tube is fixed with the big gear.. so, when we turns the gear, the scuttle system rotates.. and when we turn the shaft.. the prop.. and here i used a two way switching mechanism, to power up the gear box to drive the scuttle drive.. if not, it will become complicated that to use micro controllers, or servo streachers.. here.. nothing..