Rod Gnomon Hole Placement

[John Carmichael]

Hello All:   Because of the importance of rod gnomon attachment on stained glass sundials and the interest in the subject, I thought I'd make a Delta Cad scale drawing for the website showing a sideview of the hardware used to attach it to a pane of glass, using the bolting method.   Before I made the drawing I already suspected I see one very interesting detail. This may come as a surprise to most of you, but the drawing clearly shows that the center of the sundial, where the hour lines converge, IS NOT where you drill the hole in the glass!  This is true for all those bent rod gnomons that are not perpendicular to the dial face. And it applies to all sundials with bent rod gnomons, not just stained glass ones.   In my drawing, I used 1/8" (3mm) thick glass, 1/4" (6mm) thick rod gnomon, 1/2" padded and flat washers, and 1/4" nuts.  You can see that the glass hole is .371 inches (9mm) below the dial's center.   This is an important design consideration that the designer must consider in his plans.   John     John L. Carmichael Jr. 925 E. Foothills Dr. Tucson Arizona, USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Sundial Sculptures Website: http://www.sundialsculptures.com Stained Glass Sundials Website: http://advanceassociates.com/Sundials/Stained_Glass Attachment converted: Macintosh HD:Rod Gnomon Attachment Detail.pd (PDF /CARO) (000949A4)