Yes, Craig, you are right in all you said:
- However, the 1.8º resolution divided by 1/120 reduction, will give a theoretical resolution of about 1'.
Even if I use my most powerful eyepiece, a 2.3mm Celestron, at a ridiculous magnification of 742x, or 57x per inch, the field a the telescope would cover (with an apparent field of view of 60º) would be about 0.1º or 6'
I do not intend to use such large magnifications, but even so the resolution of the stepper would be useful. That is with no microstepping.
But if I use microstepping the motion will be much smoother, as you say, and that is desirable when tracking objects through the sky.
I do not intend to do astrophotography, and I do not really care if the stars move a bit jerkily on the eyepiece, but it is nicer if they do not.
BTW, that is the eyepiece I use to test my mirror. It is too powerful for everyday (every night) observation. I think the maximum magnification I will use will be 185x, provided by a 8 mm eyepiece.
Oh, and I heard what you say about 5 phase steppers and their increased resolution. I had no idea about that. I will pursue that line, although a quick google search has informed me that the prices are far higher than those of 2 phase steppers.
Anyway, let me see if I understand it properly: If I use 1/8 microstepping, it will be smother than full step, but the resolution will be 1/2 step?
That would be wonderful, because I always use full steps for my calculations, and that would double my resolution.
- It is also true that I have mistaken voltage and torque. I have read many times about that misconception but it does not seem to sink in. Sorry.
Naturally I have been running some test with those steppers and drivers (Nema17 42BYGHW811 and HY-DIV268N-5A), and I have tested them at a variety of currents (0.2 to 2.5 amps) both at 12 and 24 volts. They work better at higher voltages and currents.
Truth be said, I demanded high speeds from the steppers, and that must be the reason why higher voltages yielded betters results.
That was another project, on Arduino.
It seems that more tests are required.
Anyway, despite the fact that tracking celestial objects will require very low speeds, changing the aim of the scope will be more convenient if the steppers are capable of achieving high speeds. 6 volts seems too low for that. Maybe I can make a large 18-19 volt battery that can power both the steppers and the laptop I will use.
O perhaps I can use a two small car batteries in line or a 24 V truck battery to power the steppers and, of this 24VDC to 18DVC to power the laptop
https://www.powerstream.com/dcdc-24V.htmI will see in due time. Advice is welcome, though.
- The geared motor on the link would be very nice, but I have read that it is not that easy to wire it, and they do not ship to Europe, where I live. I will keep an eye for more harmonic drives out there.
Patience pays off.
- I do not know how to reduce the current of a motor from Mach3 or the computer (to reduce power consumption when stopped), only from the switches on the drivers.
Thank you, anyway, for the deep hindsight you have given me.
Diego