|
Yes, providing the threaded rod is accurately curved, it should track just a tiny bit slower than the King rate. (15.041 "/s).
Your device:
Tracking displacement angle per min = ATAN {Pitch(mm) / [Radius(mm) x 60] }
Tracking rate of your device in arc sec per second = 206265 * ATAN{ (25.4÷24) ÷ (242*60) } = 15.034 "/s
So assuming a perfectly accurate construction and perfect 1rpm drive rate, you'll accumulate 0.007 "/s lag error. This accumulates to about 2" in a 5 min exposure + any construction & motor error.
Note: It's impossible to build these things perfectly accurately.
For example, if the radius is 243mm instead of 242, then the drive error is 10x bigger 0.07"/s or 21 arc sec over a 5 min exposure.
21 arc sec over 5 mins corresponds to approximately 1.5 pixel drift using a 50mm lens and 8 pixels drift with a 300mm lens.
If the tracker is accurately built, then the drive error is about 1 pixel in 5 mins with a 300mm lens.
I'll look forward to see your results.
Good luck!
Joe
|