Hi Guys, I have resurrected my home built Clock Drive if one wants to call it that, some of you may recall it, and did some adjustments and testing to see how accurate my numbers calculations actually were.
Using the “Noon Solar Shadow” suggested here by an IIS member and the correct Latitude of Warrnambool and having a very level structure the results are thus.
I figured my calculations were pretty good, but wanted to see how close I actually came to the SCP with this contraption so I mounted a 600mm long Poly Pipe which was painted black inside and out and mounted it on top at the same angle as the Latitude measurement.
I had a 50mm lens and a Canon 5D, fitted the Lens and shoved it up the pipe, it was a perfect snug fit not needing any support, and looked through the Camera and centered it up the pipe.
I waited till dark, took a long exposure and presto, nearly spot on, (50mm @F4.0 for 35 mins)
The image is full of noise and hundreds of hot pixels but it is clear that I nearly got the SCP in the middle, maybe a tweak to the right and a very small tweak with the latitude and I should be spot on, or should I just leave well alone and leave it there, I think it is pretty good.
I now have it set up and secured that it will always land in the same place after I remove it and then put it back, so the alignment won’t change, the photos attached will show how it all went together.
Now for the real test, with a camera and lens attached and actually tracking something.
This Machine was built with a curved ¼” threaded rod arrangement with a pitch of 24 to the inch, and set at exactly 242mm from the center of the main angled shaft supported through a bearing set-up, and one RPM small electric motor, I found this in an American Astronomy Magazine many years ago.
Radius = 1436.5 x ( n/2 pie t ) where n = 1 and t = 24
Radius = 1436.5 x ( 1/2 22/7 x 24 )
Radius = 1436.5 x ( 1/6.285714 x 24 )
Radius = 1436.5 x ( 1/150.85713 )
Radius = 1436.5 x ( 0.0066287 )
Radius = 9.52212 inches, (241.86184 mm)
Apparently this set up according to others works very well for reasonably long exposures.
Thanks for looking
Leon