I would like to make a sundial with the dial face oriented in a due
north-south direction and tilted upward toward the north celestial pole (41
1/2 degrees at my latitude), such that a perpendicular line through the
dial face will point to the intersection of the celestial equator and the
Luke
Your statement that eccentricity will always be synchonous to the passage
of perihelion needs, I believe, amplification. There is no a priori reason that
I know of that the mean sun and the actual sun should have the same right
ascension at
perihelion. The fact is that one may choose the
graphs of the EOT for successive millennia from about 3000 BC to 4000 AD.
It also has the complete equations for two methods of computing the EOT.
It is a great book of algorithms for solar, lunar and planetary positions,
among other things.
Gordon
Gordon Uber [EMAIL PROTECTED] San
Bill,
If you'd like to see a more graphical representation of these two
effects (obliquity and eccentricity) and their relatives weights, see
the following URL:
ftp://ftp.gcstudio.com/pub/sundial/sday_eot.gif
I too would recommend the Bernard Oliver (of SETI fame) SkyTel
Hi All,
I don't know how much help I can be with plot files beyond how to
produce them. I have never actually plotted one. I have used them as an
intermediate format for line drawings created in a proprietary format so
they can be imported into a word processor.
I will try to address some of
John,
Great stuff. I have been outsourcing all of my anodized worked. Especially
since they can do a brass - like color, but your success encourages me to bring
my one of a kind work home.
Are you saying that you use a positive mask?, i.e., Black lines on a clear
field. If so that's
All,
I have shipped 16 of the 20 copies of DeltaCad that I ordered.
Attached is a script I wrote to draw a noon mark for a dial that that has
the aperture at 36.125 above a dial face that sits in the plane of the
poles. I think that its accurate, but we have not built anything with it
yet.
Fellow Plot'ers:
Bob gave an excellent step-by-step to get a plot from a CAD program. I too
use the 7585A and for those who like me need the picture in addition to the
plot, I add:
A combination of events lead to this method; Microsoft no longer included
the hpgl filter, my CAD program no
A HPGL file is gets often .plt extension, that is all. Sometimes .hgl is
also used as extension. So: PLT is not a file format.
My MS Word can read a .plt file (thanks to a nice filter) and the result is
a nice vectored picture in a document that can be scaled to any size
without losing resolution
