This machine can be used as a star tracker, solar tracker or I use as a mirror (get the right position to reflect the sun light inside my house).
I didn’t like to use a SD with text file with loaded all the coordinates of the sun, but Since at my engineering course I studied a lot about the sun, classic mechanics and about earth movements I rebuilt the equations with high accuracy 0.1% (it counts the reflection of the light with the atmosphere too).
I use the ESP8266 (WiFi module) to get the real time from internet and check the weather conditions.
If it rains I move the mirror to protect ( as additional roof) the case as much as possible from the water.
It uses internet to download wind strength and direction and if it is dangerous it puts the mirror in a “flag” position.
(a 30Km/h of wind can cause almost 50 N of forces and a high torque (15Nm in the worst case) with a 1m^2 of mirror).
I used this configuration with spring because I can raise significantly the load. With the right springs you can made a torque of 9 Nm with just only one nema 17.
In my case with a total spring of 750N/m and a load of 3Nm i have this result
(SEE THE MATLAB GRAPH BELOW)
As you can see in the graph, my motor has to do less than 1Nm of torque instead of 3Nm.
Gear--- I tried to use as mush as possible bi-helicoidal gear gears for better performace( less noise and less backlash),
The elevation gear has a ratio of 1:202, the azimuth gear-motor has a 48.22:1.
I used gears for the potentiometer too (2.33:1) to upgrade the improve the quality of readings.
Total cost of this machine:less than 80 Euros.
I will fix errors in the guide and upload sketches in the following days.
lifting 1kg of pasta for calibrating motor's speed
Find in the table the best spring for you
Those are the main aspect of the project and all the downloads link