hmmmm... not to contradict but...
As I understand it, pitch is expressed in terms of the travel of the nut per revolution... regardless of the pitch of each "start". So if you have a dual lead screw with a "pitch" of 5tpi (turns per inch) it's moves exactly the same distance per revolution (and hence has the same "pitch") as a single lead screw at 5tpi.
Again, as I understand it, multi lead screws are used because they can carry a higher load then single lead screws (because the load is distributed across the multiple leads).
I'm not a mechanical guy so if someone could correct any misconceptions I might have.. I would appreciate it. |