[Rata]

Propellers are easy to get wrong on a paper model. The most common mistake is too much pitch or twist on the blades.
Study the blade pitch angles on a full size plane and even on flying power models and you will see that in almost every case the there is a higher pitch angle at the roots, reducing out to a shallower angle towards the tips. We can ignore the fact that a lot of aircraft have variable pitch props, as the blade itself is rigid and the relative pitch angles between root and tip stay the same.

The blade is also usually thicker at the root and I try and replicate this by inserting a sharpened length of refillable pencil lead about a third of the way into the blade, which when the glue is set trimmed level with the blade end.

Before attaching to the hub I give the blade a slight twist and when I do attach it I try and adjust each blade while setting so there is very little pitch at the tips.

With the prop on this model is now complete and it's another winner from the S&P stable. Thanks again Bruno.

I hope posting this was of some benefit to other members and if I've failed to make myself clear on any particular thing please ask.

I'll be making further ongoing additions to this thread explaining the build aspects peculiar for example to biplanes and multi engine types. Thanks for looking in.