Messing around with sundial

[LCHIEN]

Always curious about time keeping, clocks and... SUNDIALS

Quick research on the internet says the gnomon has to be at an angle same as your latitude... mine is 29.76°
cut a guide alignment block at a hair less than 30°. Using a 4" nail as the gnomon.
My other choice was drilling a hole at almost 30° using the drill press and a angle drilling jig of some sort with a 1/8" or 3/16" dowel as a gnomon.


30 minute project later...


So the next instruction is to point the gnomon at the north (solar) pole.

darn. Overcast.
Needs new batteries, I guess.

The long term problem is the 5, large 33-year old live oak trees. Not too many continuously sunny spots left on my property.

[leehljp]

"darn. Overcast.
Needs new batteries, I guess"

They just don't make them like they used to!

QUESTION: How did you arrive at the placement of the horizontal line that is marked with "6" on both ends, and is where the gnomon is also located?

[LCHIEN]

"darn. Overcast.
Needs new batteries, I guess"

They just don't make them like they used to!

QUESTION: How did you arrive at the placement of the horizontal line that is marked with "6" on both ends, and is where the gnomon is also located?

The point of the Gnomon is located on that line, I arbitrarily chose that point, close enough to one side of the base to still have 6 oclock radials of a decent length. Any farther down and the 6 o'clock radials would be very short. Higher and you'd just use half the base.

So yeah, the point of the gnomon is a little off. I drove the nail after I drew the markings...

You could in fact lay this out on a square or rectangular base, some use a semi-circle; a circle is not a requirement. The time lines radiate outwards from the junction point of the 12-oclock radial and the 6 o'clock radials. One hour every 15°.

Higher latitudes with long summertime daylight hours you can put radials for 5 AM and 7 PM below the horizontal line and see shadows.

This clock doesn't know about DST, though.

If you look at this one, the line connecting 6 and 6 (VI to VI) is through the base of the gnomon. and the Line is offset from the center of the circle an arbitrary amount.

[LCHIEN]

A few other designs. Pondering what I could do to make an interesting modern looking design.
Building a quickie always gives you insights.

A useful link:
https://www.instructables.com/Horizontal-Sundial/

And you can get your Lat/Lon by right clicking on your location on Google Maps.

[capncarl]

How about a 3D printed digital sundial? My oldest printed one out several yrs ago for me to play with. Mind blowing! I didn’t set it up in a permanent location, if that’s even possible. Google it.

[LCHIEN]

I saw those... clever idea.

[LCHIEN]

So I learned one thing already... using a round item like a nail for the gnomon is not a good idea.
The shadow it casts is wide so making the time determination imprecise.
The use of a triangle as a gnomon casts a sharp line of light/dark which is much more precise. Its only a wide shadow at noon.