Great idea. A beautiful form for this type of dial. Thanks for passing
on the link.
This seems a form that was referred to as "punctiform" by Gianni Ferrari.
His article, " Sundials With Punctiform Hour Lines", was in the
Compendium for September 2004.
It is available on line at
http://www.advanceassociates.com/Sundials/Stained_Glass/sundials_files/Ferrari_Gianni_Sundials_with_Punctiform_Hour_Lines.pdf
He describes sundials with "hour windows" much like what is described in
this Instructable.
It seems this "Time-oclock-shadow" is a concept simulation using a 3-D
drawing program. The author states:
"Using Autodesk Inventor I first started tracing the angles on a sketch,
then I created planes that went through the hour lines and the gnomon
line. The hard part is done! Using each plane, extrude the right number
out of it."
Actually making such a dial would be difficult to "extrude " numbers.
Maybe a laser cutter?
As noted by one comment, the numeral form window might suffer some
eclipsing from changes in solar declination. That is something he could
check in his 3- D program. It would be easier to have a wide window
that in turn shines on cut out numerals.
It is also notable that the guiding principle the author used was the
hourly shadow planes. I used the same idea some years ago in making
hour windows filed with vanes of those shadow planes. I never made a
permanent model. Just a cardboard model was very time consuming to fill
a sizable window with a few dozen vanes.
- Claude Hartman
35N 120 W
On 4/23/2015 5:24 AM, Richard B. Langley wrote:
Came across this, this morning:
http://www.instructables.com/id/Time-oclock-shadow/
--Richard Langley
-----------------------------------------------------------------------------
| Richard B. Langley E-mail: l...@unb.ca |
| Geodetic Research Laboratory Web: http://gge.unb.ca/ |
| Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142 |
| University of New Brunswick Fax: +1 506 453-4943 |
| Fredericton, N.B., Canada E3B 5A3 |
| Fredericton? Where's that? See: http://www.fredericton.ca/ |
-----------------------------------------------------------------------------
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
