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Thread: Sundial layouts

  1. #1
    Join Date
    Mar 2009
    Location
    Red Deer, Alberta
    Posts
    829

    Sundial layouts

    I'm hoping that someone here has, or can direct me to, a SIMPLE design program, method, etc of calculating hour vector line for a horizontal sundial. My understanding that the line are not equal, but are different angles as the day changes.

    Anybody have any solution and or suggestions? Ideally, a program where I can enter the latitude and it will calculate the angles based on that for each hour. I can get the rest - angle and location of the center gnome (center piece) but am completely stumped on the hour line layout. I would like it to be pretty accurate as well if possible.

    I have done a lot of searching, and an only find sites that use formulas that I can hardly read, let alone understand!

    Appreciate any and all help!

    Keith

    My Latitude = 52.26N
    Funny, I don't remember being absent minded...

  2. #2
    I found several sources in a Google search. One that seemed pretty simple is here. Just pay attention to the first half and skip the bottom half.

    The layout of the dial is pretty straightforward and the gnomon has to point to celestial north, which is the angle of your latitude. You'll need a compass or some way to point the whole thing true north, not magnetic north.

    Mike
    Go into the world and do well. But more importantly, go into the world and do good.

  3. #3
    I've been interested in sundials since I was a child. My favorite book is Sundials :Their Theory and Construction by Waugh.
    Years ago I made and sold a few cast from pewter. Made them to standard time here. If I did one now I would make it to local time. That is really your bigist decision. You can get a true north south line ...on line,but it is easy and interesting to lay out the way the ancients did.

  4. #4
    The programmatic drawing tool Nodebox can do that: http://nodebox.net/code/index.php/Sundial

    If I remember correctly, the source is clean and well-documented, just change to your latitude and longitude and the program creates the file to match.

  5. #5
    Longitude is needed for a dial that will match your time zone ,but not for the traditional sun over head at noon type. Both types need a corection chart to corespond with clock time. That is due mainly to the earths elliptical ,rather than round orbit. There are some dials dating to early 20th century that always tell clock time ,complicated and not often found.

  6. #6
    Join Date
    Mar 2009
    Location
    Red Deer, Alberta
    Posts
    829
    I found several sources in a Google search. One that seemed pretty simple is here.


    Thanks - I had seen that one, but had missed the hour angles...

    Thanks everyone. What a great bunch on a great forum.
    Funny, I don't remember being absent minded...

  7. #7
    A bit late, but I've just added a sundial template generator to blocklayer.com
    You can make a full scale template, or print cut and fold (popup) a working sundial.
    Just enter your Latitude (you can find it on the page) and drag the slider to size.
    blocklayer.com/sundialeng.aspx
    Last edited by Keith Outten; 10-08-2017 at 12:03 PM. Reason: Spellen

  8. #8
    Join Date
    Mar 2009
    Location
    Red Deer, Alberta
    Posts
    829
    Thank you! Great looking site.
    Funny, I don't remember being absent minded...

  9. #9
    Join Date
    Mar 2012
    Location
    Virginia and Kentucky
    Posts
    3,298
    You know folks are writing about sun dials, antique pencils, Model T automobiles, etc. and my mind somehow wonders how Ken Fitzgerald is doing these days. He likely has lots of information and experience on all those topics.

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