Dual Axis Solar Tracker

by OpenSourceClassroom, published

Dual Axis Solar Tracker by OpenSourceClassroom Feb 23, 2013

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If you have made this thing, PLEASE take pictures and post! Thanks.

This is a simplified dual axis tracker for small solar projects. Notice that the weight of the tracker is NOT putting pressure on the servo motors. The pitch gear is nestled inside the bracket which reduces wobbliness and makes the installation look professional. For the horizontal gear system it just made sense to attach the entire panel mount directly on the gear. It makes for a really solid structure. This was my first attempt at a project like this. Let me know how it works out if you build one... Enjoy!
Here are video links:
Here is a simiar project with no printed parts:


You need: Arduino Uno, (2) SG90 Micro servo motors, (4) LDRs, breadboard, wires, rainbow ribbon cable for LDRs, 4" long 1/4" bolt and nut.
Print all parts.
Attach horizontal servo motor to tracker base before attaching the horizontal gear or you will have trouble with tool access to get the motor mounted. The vertical servo gear should be ok to assemble first due to the smaller size. To mount the gears to the servo motors, I cut tiny brass nails just a bit smaller than the thickness of the gears and made little groves on the nail to give a rough surface for the plastic to bond to. I then used a soldering iron to heat the nail and fuse it through the white servo gear attachment and then into the plastic gear. Makes for a nice, clean installation. Just make sure that your gear is exactly centered when you mount it to the servo.
Attach motors, gears, and panel mount.
Hook up wires according to schematic.
Load program into Arduino and test it out.
Depending on the light that you use to move your tracker around, you might need to change the resistor size on breadboard (they should all be equal value, higher value resistors for less light).

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Can Stepper Motor be used instead of Servo?

i my name is victor,and i´m doig this project,
but not work correctly.
Someone tested this code?
help me, my email is [email protected]

i my name is victor,and i´m doig this project,
but not work correctly.
Someone tested this code?
help me, my email is [email protected]

Hi there. I was thinking you could use a motion sensor as well. Then you could put a camera on the platform. Has anyone tried this?

Hi, its a lovely design

i would like to mod it and use it as an antenna tracker... what tool did you make this in?

Try using Autodesk Meshmixer. It's free and you can load in STL files and make alterations to them. Its a pretty cool program.

I guess it would also possible to scale this up for bigger servo correct? Planning to use this for antenna tracker

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I guess it would also possible to scale this up for bigger servo correct? Planning to use this for antenna tracker

Can someone please explain the Arduino code below? I am confused by "analogRead(4)/20" and "analogRead(5)/4" because based on schematic, it does not look like analog pins 4 and 5 are used.
int dtime = analogRead(4)/20; // read potentiometers
int tol = analogRead(5)/4;

Sure thing. This arduino code was originally sourced from http://www.instructables.com/id/Arduino-Solar-Tracker/http://www.instructables.com/i... but after configuring the code with the printed parts, I did not use the potentiometers in the circuit. We just changed the resistors depending on the intensity of the light source being used. In the classroom with an artificial light source, the extra use of potentiometers seemed to complicate the project and therefor were not used. I assume that the section of code you are referring to can be removed without disturbing the functionality of the system.

I really like this sun tracker. Just a question, what is the maxium size solar panel this setup can handle? I'm looking for a solution that can handle a 10kg ~100W panel with the dimensions 100x70x4 cm

Not sure if this mechanical design can support a 10kg panel. You will probably need to design a larger capacity mechanism and use larger servos with an increased power supply.

You did a great Job on this project and have provided me a great idea that I wanted to share. Why not inverse the horizontal gear from the outside of the base to the inside? Place the stepper motor under the column created. This would minimize your base foot print and may even allow you to mount the whole slew gear onto a poll. I like it because it expanded my mind to what is possible. You helped me greatly by providing the "spark". Thanks!

Hi there, I was wondering if you could post the Inventor file for the vertical servo gear. I am going to add a small hole in the center of the gear so I know exactly where the center is when adding it to the servo

How much power does one get with this setup? Anyone do performance benchmarks yet? Ideally one could setup 2-3 of these in a backyard or something and print recycled plastic from solar power.

where did u buy the parts for this??

Online. Just search for the light dependent resistors, Arduino, and SG90 Micro Servo. I think I got the solar panel through Adafruit's website

Hi Rob,
Nice work.
Where do i connect the potentiometer?
where are the 3 pins connected ?


There is no potentiometer. In the download files you will find a wiring diagram that I put together using powerpoint. That should help you tremendously.

Thanks for sharing this project. You did such good job on it I had to build one, so... I'm printing the parts now, and should have it assembled and working by tomorrow. With my Dimension printer total print time will be about 22 hours which is not too bad. I'll post a picture when it's done.

How do you like the Dimension printer?

It's a great printer. The print quality is excellent and the support system is very clever, but like all of them it's slow. The only down side is the cost of the feed stock.

Mainly ABS plastic right? Is your dimension printer... yours or for a school? Aren't they super expensive?

Sweet! Just be careful with the Arduino code. Make sure that your sensors are easily distinguishable when plugging into arduino. Your code should reflect that exactly. That was the biggest hurdle I had with the project. That's why I found the multicolored ribbon cable to be helpful. I drew the schematic on ppt based on my model. Your model may be a little different depending on what color wires you use.

The parts are finished, assembly tonight!

post a video of it... I am going to make one when my printer arrives. let me know if there are tricks to getting it to work....

Thanks. I have the arduino USB plugged into my laptop for power. Arduinos have a variety of power supplies that you can use. The arduino program code is as simple as I could make it for dual axis tracking purposes. If you know about arduino programming, you can add the proper language to make it do whatever you want (in absense of light return to a certain position=sunrise). Too much for me at this point. Good luck and post if you make one. I'd like to see how it turned out.

I like your design a lot. What is powering the motors and arduino board? Do you have a separate power supply for the motors and board? I'm interested in using a similar design and was wondering how it powers itself to return to sunrise?

Can you also build a star tracker? =)