the gnomonist question of the day
Hello all sundial lovers I have a gnomonic game for you (in French and English only, sorry for Italian people): How to read the time on this dial http://pagesperso-orange.fr/cadrans.solaires/cadrans/cadrans-interactifs.html Here are some clues, warning some are useless: - it has got 4 CDs - the CDs are on an helix - the observer can turn the helix - we are 12 days after the spring equinox - helix support is polar - the magnolia soulangeana is flowered You can send me your answers Joël from France <<_thb_cadran-bruz-14.JPG>>--- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: 3D analemma
Hi Art, I saw that you could solve your problem. It would be great if you could post/mail us your solution! In short mine is the following: I created a pythonscript in blender3d to create the gnomon (either one "medium" or two like Bernhardt or something even more sophisticated) as a 3d model (see my picture at http://commons.wikimedia.org/wiki/File:BernhardtscheWalzen.png). Blender then can export it to many formats which a CNC can probably print (including eg .dxf). Unfortunately I do not have any experience with CNC, but I'd be interested in your results again. I made one with a 3d printer at university, see some prictures at http://picasaweb.google.com/finbref/Sonnenuhren Let me know if you want/need more details, Thomas 2009/3/26 Thomas Steiner : > Hi Art, > I am very busy at work, perhaps i can only look at your problem later, > perhaps on the weekend. But as far as I understood, I do have a nice > solution for you. > If you don't hear anything from me within a week, please recontact me. > Thomas > > > > > 2009/3/26 Art Krenzel : >> Thomas, >> >> I saw your recent posting on the sundials listserve where you discuss >> analemmatic sundials in detail. I joined NASS about a year ago and have >> been reading the sundial list serve during that time. >> >> I have a problem which you might be able to help me solve. I am trying to >> convert a standard equatorial sundial using a simple rod as a gnomon to one >> with a gnomon based on a 3D analemma. This will reduce the amount of >> analemic adjustment from every month to twice a year (to compensate for >> daylight savings time). I have included a photo of a sundial of the type >> which I am seeking to duplicate. >> >> Specifically, I am seeking a program which will plot the shape of the >> analemma on an X Y grid so I can feed the values into a CNC lathe to shape >> the 3D analemma. I want to take the X values and "average" them such that >> the data forms a symmetrical analemma around a central axis. Symmetry of >> the analemma design will introduce small solar compensation errors however 2 >> minutes or so will be acceptable. >> >> To review my goals - I need the two dimensional analemma plotted in XY >> coordinates, not days so I can enter the graphical coordinates into a CNC >> machine. The software on the CNC includes curve smoothing capability so it >> will round the surface produced by the data points nicely. I do use >> DELTACAD. Is there a macro which might do what I need? I have not been >> able to locate one. >> >> I would appreciate your assistance to solve this problem. >> >> Sincerely, >> >> Art Krenzel >> 10505 NE 285th Street >> Battle Ground, WA 98604 >> 360-666-1883 voice >> phoenix98...@msn.com >> >> > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Shropshire Sundials And Google Earth
Back in December, Roger Bailey set us a challenge for 2009, to populate a sundial database and display the details using Google Earth. I rose to the challenge, in a small way, and here is the result on my website: www.shropshire-sundials.net I hope you to enjoy it. Roger also showed us how to start a sundial trail using Google Earth and in a later post more ideas on how to add content to the KML file. My approach was somewhat different, I decided to work directly with the KML language. KML stands for Keyhole Markup Language and is a simple, human-readable format used by Google Earth and now by other Earth browsers like Microsoft Virtual Earth and NASA WorldWind. KML 2.2 is now an international standard , located at www.opengeospatial.org. To give you an idea of what KML is like, here is a short snippet: line 1 2 3 La Nef de Tavel 4 5 La Nef Solaire was built in 1993 at a motorway stop near Tavel in the Midi of France.6 Designed by sculptor Odile Mir and well-known "gnomoniste" Denis Savoie, this is one of the largest and interesting dials in the world 7. 8 9 4.70031,44.0013 10 11 12 13 Type it into your text editor, such as Notepad, save the file as "La Nef de Tavel.kml" and then click on the KML file to open up Google Earth and see the aerial view of the huge, incredible Nef de Tavel..The KML text is quite simple to understand.The lines 1 and 2 show that this is a KML version 2.2 file, itself a version of XML. The Placemark beginning and end tags, line 3 and line 12, enclose the mininum information for a placemark, a name for the location, line 4, a description, in this case, line 5 to line 8, and a ponit, lines 9 to 11,which contains the placemark's coordinates. Note that the coordinates in decimal degrees are first the longitude and second ,the latitude. N and E are positive (+), S and W are negative,(-). If you open up my "Shropshire Sundials" KML file with a Right-Click and use your editor, you will see a number of KML features which I have used to produce the effects in Google Earth, including: *Icon Style - the gold icons for the placemarks *Balloon Style - which prescribe how the balloons created *Network Link - which links this KML file to another KML file *Placemark- like the Placemark for "la Nef de Tavel" but with two particular important features - Description includes hyperlinks to either a website which contains photographs and a more detailed description of the dial, the location and its history. - Look At feature wh
