I like the double bolt design too for its stability (the gnomon can't swivel if the nuts are loose). And the pressure us spread out over a larger surface area. It does involve precise welding or soldering of the gnomon to the gnomon base plate however.
Placing larger washers on my single-hole design would spread out the pressure too and solve that problem, but would not solve the problem of rod rotation, unless it has a support stay. Both designs seem pretty good. 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 ----- Original Message ----- From: <[EMAIL PROTECTED]> To: "Sundial Mail List" <[email protected]> Sent: Monday, August 04, 2003 10:44 AM Subject: Gnomon attachment > Fellow Shadow Watchers, > I've been thinking around what I would attempt as > the attachment for a stained glass gnomon. It would have to > > 1. be neat and unobtrusive > > 2. give a good contact area extended down the noon line to avoid local > stresses > > 3. allow the possibility of the gnomon rod axis coinciding with dial > origin if desired - problem identified by John C. > > I've attached a tiny 8k GIF of the result of my thinking. > > See < Gnomon basr.gif > > > If the screw holes were first drilled in the front plate and tiny hole > drilled to coincide with the origin on the glass the locations for the > holes to be drilled in the glass could be marked exactly using this as a > templet before assembling and soldering the screws and gnomon rod. > > Tony Moss -
