The shaft on the prop adapter is far too thick for the centre hole of the propeller so I can't get that on there, is there something else I should be using? Also if I try to use the little thing with the two screws sticking out (the thing on the left), there isn't actually enough vertical space on the prop shaft to fit both the prop and that thing.
EDIT: Here's some photos I took, they're a little blurry but I hope they help to illustrate the problem.
's the prop shaft being too short.
's me showing that the centre hole is too small for the adapter.