I have noticed that many topics are often repeated.
Furthermore, many questions are asked again, even though there is no need to do so if you read old topics that have already been covered previously.
It's normal in a forum, but it's a shame that a lot of information is lost in topics that are too old to be easily accessible.
The "search" button does not always solve problems.
In this case, entering the word "propeller" in the search field will give you the most useful links.
Let's say that this could be another way to facilitate those who are less familiar with the functionality of this forum which, I must say, is really very well done.

For these reasons I have collected three topics below that could be useful to everyone regarding naval propellers:

https://model-boats.com/forum/135377
https://model-boats.com/forum/135991
https://model-boats.com/forum/135981