Helix parameters

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renatorivo
Posts: 2254
Joined: Tue Feb 21, 2012 8:07 pm
Location: Torino - Italy

Helix parameters

Postby renatorivo » Sun Mar 24, 2013 9:25 pm

Hi,

About Helix parameter (helix: constant angle with a fixed direction), I think that:

Pitch is in fact step (gap, increase, distance between two coils) if helix is cylindrical. Pitch should be an angle.

Heigth is right when the direction is Z and helix is cylindrical, otherwise is total length or ?

Conical helix is in fact Conical spiral of Pappus or not?

Radius with conical helix is Start radius (radius is not constant).

What do you think? This is also useful for the wiki.

Thanks
jmaustpc
Posts: 9566
Joined: Tue Jul 26, 2011 6:28 am
Location: Australia

Re: Helix parameters

Postby jmaustpc » Sun Mar 24, 2013 11:48 pm

According to wikipedia
The pitch of a helix is the width of one complete helix turn, measured parallel to the axis of the helix.
You may like to read this and the other pages it links to
http://en.wikipedia.org/wiki/Helix
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NormandC
Posts: 18534
Joined: Sat Feb 06, 2010 9:52 pm
Location: Québec, Canada

Re: Helix parameters

Postby NormandC » Mon Mar 25, 2013 12:06 pm

That's English for you, a word can have two totally different definitions according to context. ;)

You were thinking about pitch / yaw which is a different thing.

In French (and I'm sure in Italian) two different words are used so there is no confusion.
renatorivo
Posts: 2254
Joined: Tue Feb 21, 2012 8:07 pm
Location: Torino - Italy

Re: Helix parameters

Postby renatorivo » Mon Mar 25, 2013 3:08 pm

Thanks

ok for the two meanings in English.

Is not a very important issue but I think that in the Italian version of FreeCad is best to use "Passo" instead of "Beccheggio". According to wikipedia http://it.wikipedia.org/wiki/Elica_%28geometria%29 and to avoid confusion with Placement/Euler angles.

However, in the case of a Conical helix, the pitch is not measured parallel to the axis of the helix or I'm wrong?