Hello people;

first, i have spent some time trying to figure out which forum to post my question at, and i hope this is correct. Please remove it in case i was wrong. i hate breaking the rules

Well, i'm working on a project of manufacturing an in-house volume control dampers, i'm working on the design now and it's almost done.

However, i'm still stuck at some points without any answers:

1- how to decide proper number of blades ? (in case of having diffrent widths, e.g.: either 5 blades of 4" or 4 blades of 5")

2- how to decide where to place the extended shaft or the manual handle, top balde or center or bottom ? based on what.

Thanx in advanced guys.