Quote:
Originally Posted by Wavytone
...complete with period errors arising from such a small pinion.
Would have been much better if the teeth had been helical, or use a toothed belt between the two.
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Yes, I know.. but I had only this one in my drawer....
If ever I stumble on the suitable helical gear, I will print the new matching sector - it is easy enough to do.
And it can't be belt (in conventional configuration) because I keep the OTA and mount separate when not in use (when put together they are too heavy to handle)... and I do not want to complicate assembly - this way, I simply put the OTA in place and encoder (and drive) is automatically engaged.
BTW, period of PE (due to teeth engagement) is a bit less than 1°, not sure about amplitude...
Since encoder inputs are used to calculate the tracking rates for EL and AZ motors, even 1° accuracy is good enough for visual.
If I need any better, I simply sync the system with observed (or photographed) object from data base (which is a bit fiddly process, not wanted when in dark and people around waiting for next object to have a look at).