Hello Everyone, My name's Tushar. I'm from India.
I am interested in making a "Star Tracker". It would follow the rotation of earth but in opposite direction. This way the sky will look static. I wish to capture some shots of Milky way with my phone.
So I was skimmimg the internet for a setup that can rotate my phone, which sits in a phone stand, on a tripod, at a rate of 0.0007 RPM or 1 rotation per day.
My phone weighs 380 grams and the phone holder is 170 grams, so i need a way to move this ~700 grams setup at the rate of movement of stars. Not only this, I am also saving up to buy a small telescope, and the one i have in mind is 1.4 kilograms. So if i couple the telescope with my DSLR camera, the weight goes somewhere around 2 kilograms. So i wish to make a tracker that can have the payload capacity of at least 3 kilograms so that the gears or the motor don't have to over-exert themselves. I know it would be overkill for my current setup but it will be perfect for the future setup i wish to have.
I tried programming the arduino with a DC motor of 200 RPM (have 3 of those). I was sending pulses for 10 milliseconds, after every 10 milliseconds. This isn't in any way precise speed of tracking for any object. I was just trying out the codes and checking the torque. I soon realized that the torque was so low that if held between thumb and index finger, the shaft stopped. So now i know that the DC motors i have, wont work for the desired output at such slow RPMs.
Some online forums say its wise to use a stepper motor in a configuration that's called a "Barn door Tracker". But I am not interested in that design.
Some forums say its okay to use a 180 servo because they have high torque, at slow RPMs.
I was hoping that, now that you guys know my weight and type of motion requirements , you could give me some insight on which motor should i use for the desired output and how to write the arduino code for it.
Waiting For Your response,