I hesitate to jump in here, not knowing the background, but would like to offer two observations.
I have been working on photo-engraved brass dials under the generous long-distance tutelage of Tony Moss, starting from a video that he presented at our most recent NASS conference. Using this method, virtually any artwork that can be rendered through a drawing program, including the figure 8 analemma can be etched into a brass plate. The method requires some equipment and chemicals, but the investment is extremely modest compared to a CNC machine and the results can be quite spectacular. (Did you actually make that yourseif?) I also have used, and still use, François Blateyrons excellent shadows program, but have found that for actually laying out the artwork for a working dial including a noon gap and other dial furniture one really needs to transfer everything to a drawing program for manipulation. The term analemmatic sundial is generally used to refer an elliptical dial, typically laid out on the ground where the moveable gnomon (a person) casts the shadow. An engraved analemmatic dial would therefore call for an ellipse, as noted by Julian Greenberg, rather than a figure 8 analemma design, although a figure 8 analemma can be incorporated into an analemmatic dial for reference. It would be unusual to engrave an analemmatic dial into a brass garden dial because of the moveable (and stealable) gnomon, but John Charmichael has made some very beautiful analemmatic dials engraved in sandstone suitable for use in a private setting where the gnomon can be put away and/or replaced. Are you engraving in metal? Stone? Jack Aubert From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Douglas Bateman Sent: Sunday, June 13, 2010 5:11 AM To: julian greenberg Cc: Sundial List Subject: Re: Sundials/BHI Dear Julian, I look forward to see the pictures in due course. The analemma, however, does not have a nice mathematical curve (at least as far as my maths goes) nor based on any ellipses. Some of my really high tech friends have CAD software that would take the coordinates of each point and transfer into the CNC machine - all done! Otherwise make a template smoothed by hand through the points for the engraver to follow. Regards, Doug PS Are you aware of the useful internet chat group sundial@uni-koeln.de ? On Jun 13, 2010, at 00:56, julian greenberg wrote: Enjoyed your talk on Thursday night.We spoke afterwards. Will find some pictures of my dials and send them to you. My next project will be an Analemmatic dial. However this will be difficult to make, as I have no way of engraving elipses. I use Waugh and Rohr's books as reference.I also use the french "shadows" software. Regards Julian
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
