[TheForge] Re: helical railing calculations

[Bruce Freeman]

Rob,
Your example very nicely illustrates the concept that straight lines
can be used to approximate a curve.  I think some other respondents
don't quite catch that notion.
However, in FACT, I'd be approximating the helix NOT with straight
lines but with quarter-circular arcs.  This would allow fewer "facets"
to approximate the curve.  Four per cycle (I hypothesize).  
I haven't had time yet to try this on CAD.
Bruce
NJ

>>> pierce at fuse.net 9/22/2004 10:15:10 PM >>>
Bruce and all,
Hi, newbie here. Interesting subject.
Your theory reminded me of creating a faceted helix in CAD.
Here is a visual of what I interpreted your thesis to be,
I gave the number of sections per cycle, 6 cycles total and the total 
length is 4' 6"
radius is 6" Top, side and 3/4 views. I used flat straight and not 
flat curved though.
http://www.pierceproductions.net/helix.jpg 
Rob

>
>
>Some of you may recall that I play with math for entertainment.
>Recently, I have played with the geometry of helices, as in helical
>railings for circular staircases.  The results were interesting.  The
>thesis I was examining was the feasibility of constructing these
>railings from four FLAT curves, each representing 1/4 rotation.  I
think
>the answer is yes, but I haven't tested it yet.  The question I
>addressed was, what would be the radius of such a curved railing. 
That,
>I got an answer for.
>
>Is this subject of any interest or use to anyone on this list?
>
>Bruce
>NJ
>

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