Dear Hannes,

Your problem is turning into a bed of nails...

> ...the dial I had in mind would be vertical
> and facing south-east...

That makes the problem more interesting!

> ... I can see no way, with my limited abilities,
> to get the angles of all those gnomons right.
> Any ideas?

I imagine that all your gnomons are going to be
the same.  If you can get ONE right you can get
all the others right!  Here are two questions:

  What kind of gnomon you would use if you were
  making a conventional dial with ONE gnomon?

  How would you would attach it to the dial?

You seem to want some kind of rod gnomon.  You
can attach that either by drilling a hole or by
making up some kind of mounting.

It is very difficult to drill a hole that isn't
perpendicular to the surface being drilled.  It
is probably easier to make some kind of mounting.

You calculate the sub-style height in the usual
way and then design a simple mount.  You then
go into mass production.

All the gnomons have to point in the same direction
so you have to have the sub-styles parallel.

There is one interesting constraint that you
DON'T have...

Your hour-lines don't have to radiate from the
same point.  You could arrange your sundial on
a tall thin column with the hour-lines running
down, in order, from top to bottom, say from
4h to 14h for a dial that declines south-east.

More interesting still, you could have a
24-sided post with the 6h hour-line on the
side that faces east and the 12h hour line
on the side that faces south and so on.

I have a final piece of advice...

If you really want to drill lots of holes
at awkward angles you are going to need
some kind of jig.  I cannot think of a
good way to design this jig but I am sure
there are other list members who can help.

All the best

Frank King
Cambridge, UK

---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial

Reply via email to