Hi Everyone,
I am an electronics newbie who just learned how solder circuits on a prototype board. I am currently working on a project that requires interfacing stepper motors with my microcontroller. I started looking at different stepper motors and it looks like I am getting lost. I simply don’t know where to start. I have included the details of my project. Any advice regarding the kinds of stepper motors and the direction I need to look at is highly appreciated.
My project
I am designing a solar tracker that needs two stepper motors attached to two gear systems that have a ratio of atleast of about 1:1000. I am anticipating the motors to rotate at very low speeds (probably 1 to 0.5 revolutions per second… atleast for 8hrs a day). I prefer microstepping since accuracy of the solar tracker w.r.t the sun is VERY important.
I want to execute this project in two phases:
Prototype:
The prototype model is going to be a much smaller version. I am looking for NEMA 23 stepper with a torque of about 1Nm. I am assuming that if I attach a gear system of 1:1000 ratio, my torque is going to get multiplied by approx a 1000…? (I am not a mechanical engineer either). I was thinking of Lin Engineering stepper motor (http://www.linengineering.com//site/products/5709.html ). My assumption here is that for every step (1 pulse), the motor is going to rotate by about 0.9 degrees….??? Is there any other high torque, low speed NEMA 23 motor that I should look at? What gear systems should I use for this. As for the electrical ratings, I am expecting that the motor should have about 2-3A rating (probably 30V max). What drivers should I use… I intend to buy a third party driver for my prototype.
Production Version:
I would probably need bigger and tougher stepper motors (preferably NEMA 42) as my production version would be much bigger than my prototype. I am expecting the current rating of the stepper motors to reach 10A. What motors should I look at for this purpose? As for the drivers, I plan to develop my own circuit board that is specific to my application, atleast in the production version. Which driver IC should I look at? Also, I would be happy if I can get much higher ratio… preferably 1: 360000 or so….
I am completely alien to electrical & mechanical engineering. So, any advice is appreciated. Thanks.