Sid’s Solar Panel Sun Tracking Machine 5

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The solar panel sun tracking machine in the above picture was built by Sid Frantz. Sid and I have been communicating back and forth by email in an effort to get the Open Source Arduino Controlled Sun Tracking / Heliostat System to work with his machine. There have of course been hurdles, and there are still likely more to come, but, for the moment at least, it seems to be working!

This page contains a quick overview of the tracker’s mechanics and electronics.


More pictures of one of Sid’s sun tracking machines at the Minnesota state fair have been added at this link. Very cool!

More On Sid Frantz

As you may be able to guess from the pictures, Sid does in fact build and sell these machines (along with other things) commercially. His email is sid {at} fgsinc {dot} com. If you have an idea for a project but lack either the equipment or skills to make it happen, he’s the person to contact.

Gear Reduction System

This tracker consists of 4K watts worth of solar panels. Obviously, it is one hefty beast. The azimuth gear reduction system consists of a 60:1 gearbox which then goes to a 12:112 sprocket. The altitude gear reduction system is the same but with an additional 5:1 chain drive.


The picture below shows the electronics layout. On the left, you can see the power supply. At the top are the driver boards for the stepper motors. You can also see the Arduino microcontroller in the middle. This particular variant is the Arduino Pro.

Here is a close up shot of the above.

With the Arduino removed, you can see the RTC module used for keeping the time along with its battery backup. There are also convenient outputs for the stepper motors and limit switches.

Share Your Project

Even though he isn’t a programmer,  Sid has been able to help me a great deal with the Arduino Sun Tracking program simply by relaying to me the odd behaviors that he has experienced with his particular set up. As always, if anybody has a project they would like to share, please send it along by either commenting, posting it on the forum, or by emailing. It’s more helpful than you might realize. Thanks!


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5 thoughts on “Sid’s Solar Panel Sun Tracking Machine

  • Bill K

    A very interesting project, as this array is almost the same size as my 5.5kW array. I have a Haosolar system, (2) for a total of 11kW.
    Not to dissuade the project, but several large problems come to mind, having experience with my own machine. Mine currently uses photocontrol, which works, but I am here because I would like the option of automatic placement without sensors. I do like the Arduino control setup, and the controls appear to be a clean setup but offer the following comments:
    1. The structure is very weak. Have you done any structural calculations? The base pole on mine is approximately 18″ diameter steel about 1/4″ thickness (metric) and is mounted on a 30″ diameter steel reinforced column of concrete buried 8 feet below grade. The structure for the panels themselves looks good, but between those and the base pole is also seriously weak. Static loads are one thing, a 40 mph wind is another. I will bet you a 35-40 mph wind will bend that mounting pipe, it appears to be about 6″ diameter?

    My system has an anemometer with an override for the elevation motor. When a 40 mph plus wind is measured, it places the huge “sail” horizontal to the wind for protection. Absolutely necessary. Remember, the wind force varies with the cube of the wind speed!! At 30mph, it is quite scary to watch the array bouncing around, and my structure is huge compared to what I see in these pics. But at least you have a starting point for testing. Permanent installation needs to be much beefier if you want it to last through a 60mph plus storm.

    2) The gear setup is not weather protected, and will wear out very fast. Open gears are fine for testing, but won’t last. You want this thing to last 25 years. No way with what I see here…this will last about 3-4 years max. Remember the gears run every day. Mine uses an enclosed weather protected actuator for elevation, and a very robust weatherproof worm gear drive. It will outlast the panels. Everything needs to be enclosed, water tight, and all steel should be either hot dipped galvanized or completely powder coated. Standard paint is good for max 5 years in open weather. After one year already I see thin galvanized areas needing touched up, which is no problem. If it was painted steel it would be a rested mess already.

    Please take my comments as they are intended, to help you.


    • Sid Frantz

      Hi Bill,
      I can really appreciate your concerns regarding wind loading. The pipe is 12 inch schedule 40 gas pipe, 8 feet in the ground, in concrete. The top pipe is 8 inch schedule 40 pipe.
      The gears are actually roller chain sprockets, which are able to run in the weather. I agree that gears would not hold up. I have units that are 2 years old without wear.

  • Rob

    I really like this project.
    Currently I have bough all the Arduino bits as well as a tilt sensing compass and a GPS unit these all are working, I am in the process of designing a 2.3m * 1.1 m solar panel array of 4 * 100 w solar panels for a caravan roof.
    Originally I wanted this to automatically just find the sun anywhere it was and this is still the ideal. Using GPS etc it should be possible.
    I am designing the roof fixing so the whole array will lie and then turn, shouldn’t be too difficult.
    Anyway I am not very far along with the code, but I thought I would share the idea.
    My one concern is stepper motors … do they need constant power as I keep hearing or can we get around that ?
    I will also be buying a windmill and adding it in, just so in the winter when it is more windy, we will have enough power for what ever we need.
    I hope to share my results with this site.

    • Gabriel Miller Post author

      Hi Rob,
      This is an impressive sounding project. I would indeed love to help you share it when it’s finished.

      I don’t think getting the GPS to work with the sun tracking code would be very difficult. I can show you where you can put the GPS lat long output when you are ready, although you might be able to figure it out yourself. The only thing to keep in mind is that the latitude value needs to be converted to radians before attempting to run the calculations. (Not the longitude value though)

      The tilt sensing compass might also be fairly straight forward to set up. I don’t know how you are planning on doing it up exactly, but the only thing I would be worried about is the machine over running the azimuth limit switch. If it weren’t for that, I think it would just be a simple matter of adding the compass reading to the sun’s azimuth calculation. Of course, I guess you might also have to add in a calculation for magnetic declination too.

      The stepper motors could be set up to be either constantly powered on or to power themselves off after they are done moving. It’s really up to you. I am in the middle of updating my electronics documentation. The page I just added recently features a driver board which is capable of doing both.
      I haven’t uploaded the sun tracking code for this type of board yet, but I hope to have it done within the next couple of days.

      Hope that helps!

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