Portable Solar Trackers

Build Plans for Portable Solar Tracker

Build Plans

These build plans are evolving. The original build was for a frame that could be adjusted to handle a 50-watt to a 100-watt flexible solar panel. The fact is, we need the largest solar panel we can possibly store in an RV so that we can charge our battery quickly, in about 4-5 hours. If you build your system with a 100-watt panel, I recommend the tripod with a ground anchor. If you decide to use a larger panel, use a mast mounted system that can be mounted on the side of an RV ladder, the tongue of the trailer, or, the hitch of your towing vehicle. Be sure that you can easily tilt the assembled system into position.

The build plans will walk you through building your own Portable Solar Tracker. You are welcome to modify them to suit your individual needs. I do not recommend using this mount for anything but flexible solar panels, the gear motor will not handle anything heavier. Also, flexible panels are better suited for RVs.

It is possible to modify your mount to install (2) 100-watt flexible panels by increasing the width of the cross bars. If you add a second solar panel you will need to purchase (2) MC-4 “Y” branch connectors so that you can connect the panels in parallel.

I use turn knobs and t-nuts that pass through the grommets to mount my solar panel, but this is not nearly as effective as using velcro strips. Remember, the system is not meant to be left out in high winds or heavy rain so the quicker you can disassemble the system the better.

Download and print the plans, or you can hover your mouse over a picture to zoom in.

PortableSolarTracker1

Introduction

A few years ago I submitted an Instructable for a portable solar tracker that was fairly portable, but it was not suitable for an RV. This particular build is ideal for an RV because the system was designed specifically for flexible solar panels, which can easily be stowed beneath the mattress of the RV. The other advantage is that it can easily be assembled and disassembled.

Build your own portable solar tracker in a few hours. I have provided direct links using Amazon Affiliate links but you can shop around and look for a better price.

The project will require you to purchase all of the necessary components and it will involve modifying components by drilling and screwing together parts.

This build can easily be modified. You may find a better way to run wires or remove the tripod and solar mount for storing. This system was designed to be portable. It works best with flexible solar panels because they can be stowed under a mattress. You might find that it is easier to mount the solar panel with adhesive backed Velcro strips, which would work very well. Remember, this is a portable system and anything you can do to make it easier to assemble and disassemble will make it easier.

Skill Level

Someone with basic hand-tool skills can accomplish this project.

Tools Required

Portable Power Drill w/ adjustable chuck

8 mm drill bit

Miter Saw with a non-ferrous saw blade

Tape Measure

“T” wrench 3mm

Adjustable Wrench

Standard Screwdriver

Wire Stripper or Side Cutters

1/2″ drill bit

13/64” drill bit

Follow this link to an interactive image that highlights the parts and where you can buy them.

Step-by-Step Instructions

It is certainly possible to construct this project in stages, however, I recommend mounting the tripod and PVC panel together first. This creates the base and makes it a lot easier to assemble.

Step 1 – Assembling Tripod Mount

The first step is to unpack the tripod and assemble it. Place the tripod somewhere out of the way but still make it accessible. Locate the steel square mounting plate that was included with your tripod and place it face-up on your work surface.

Lay the PVC hair cell on a flat work surface, the link I provided is for a 12″ x 12″ sheet. It is a very good substrate for mounting components on. I recommend cutting it down to 10″ x 10″ to reduce the footprint. We only need enough room to mount a few components. If you use a large charge controller you may want to keep the panel at 12″ x 12″.

Remove the pivoting bracket from the tripod pole, there are two bolts holding it on.

Remove the bolt holding the plate and bracket together. There is a rubber grommet separating the two components, remove it. Flip the plate over. Now insert (4) 1/4” washers on the bolt you removed and insert it in the side with the countersunk hole. The washers build up the height so that they make contact with the pivoting bracket, the rubber grommet is no longer needed. The grommet caused the plate to twist and we need the two pieces to be rigid.

Now, reinstall the pivoting bracket and tighten.

Place the assembly on the PVC hair cell and mark where the holes will be drilled.

Be sure to center the assembly on the panel. Drill (4) 1/4’ Holes through the panel. Tap the holes on the tripod plate with the 1/4-20 tap.

Ream out the holes in the PVC so that they are countersunk, deep enough so that the screws will be flush with the surface.

Thread (4) 1/4-20 button head screws through the PVC to secure the bracket. Make sure that the screw heads do not extend above the surface of the PVC, you will be mounting the Charge Controller and the Solar Tracker on that surface.

Step 2 Assembling Solar Frame

Locate the t-slot extrusion. If you purchased them directly from the link you should have (8) 25” (approximately) sections of 20 mm x 20 mm extrusion.

top-bottom-rail

With a miter saw and a non-ferrous blade “carefully cut (2) sections to 22” and (1) section to 40.53″.  If you have never cut aluminum it can melt if cut with a dull blade or if cut too quickly.

pst dimensions

Allow the blade to do its job and don’t force it. It is possible to use wood blades but it will dull them and they can grab the aluminum very aggressively. Please wear safety goggles, aluminum fragments can damage your eyes.

These (2) sections make up the top portion of the solar mount.

Take (2) 20mm x 20mm inside gusseted brackets, shown above and mount the 22″ section with the 39.75″ section. These brackets prevent twisting. It is easier to pre-load the screws with the T-nuts first. Loosen the screws just enough to allow the T-nut to move up and down. The extrusion should be able to slide under the T-nut. Once the 22″ section is centered, tighten the screws with a T-wrench.

Step 3 – Installing Gear Motor

motor mount panel4

Mount the gear motor (pictured above) to the mount with the supplied screws.

Position the motor assembly on the PVC panel as shown above near the centerline. Place a mark in the slotted holes where the screws will go. Use M5 screws and nuts to attach the motor assembly to the panel, slide the motor assembly toward the edge.

Mount the 8mm coupler to the motor shaft. Align the coupler so that the set screw tightens on the flat area of the shaft to prevent slipping.

Take the 8mm shaft and insert it into the coupler. The threaded rod needs to be drilled through so that you can insert a cotter pin in it. Cotter pins can be purchased at any hardware store. The idea is to minimize the amount of play, the tighter the fit the better.

Once you have drilled and pinned the shaft position one of the “L” brackets (as shown) on the shaft. You will need to drill out the hole slightly. Thread an M8 nut and wedge washer first onto the threaded rod. Next, thread on a second M8 nut and wedge washer, to secure the “L” bracket to the shaft.

The general idea is to support an M8 threaded rod parallel to the surface of the mount by supporting it on each end. The (2) “L” brackets are to be held securely in place with M8 nuts and wedge washers. A short section of 20mm x 20mm extrusion should be cut and tapped on the ends with a 1/4-20 tap. A 1/4-20 button screw is used on each end of the “L” bracket to secure it.

install 2nd L bracket

When the motor turns the threaded rod turns and the (2) “L” brackets move together. This will create a pivoting motion for the solar mount.

To attach the solar mount to the “L” brackets, pass a 1/4-20 x 10mm turn knob followed with a turn knob in each of the “L” brackets as shown in the drawing. The t-nuts allow you to slide the bottom portion of the solar mount on and off easily. Tightening the turn knobs to hold it in place.

The best way to stow the solar tracker is by separating the tripod mount from the solar mount.

Step 4 – Mounting Solar Frame to Motor

What we are trying to accomplish is to create a “pivot” point for the solar mount. The shaft of the motor acts as one pivot point and the other end has an “L” bracket with a bronze bushing to provide a low-friction surface to ride on.

Take the top portion of the solar mount, the two pieces you joined earlier, and slide them on to the motor mount as shown below. This is accomplished using t-nuts with M5 screws. Align the turn knobs and t-nuts to align with the t-slot. Slide the top portion about half way and then install the bottom portion of the mount to the top portion.

This is also how you will assemble and disassemble the unit for stowing.

Step 5 – Installing Charge Controller

To install the charge controller and the tracking sensor we will need to separate the solar frame from the tripod mount.

To mount the charge controller to the enclosure as shown in the picture above; mount it just below the motor and to the right. The Solar Tracking Module should be mounted to the left as shown. These should be mounted using self-tapping screws that are available at any hardware store.

Slide the solar assembly off of the tripod mount by loosening the t-nuts on the gusseted brackets of the lower bar and slide it off. Loosen the t-nuts on the motor assembly and slide the top portion off.

Be sure that the threaded rod, or the “L” brackets, don’t make contact with the side of either component.

Step 6 – Installing MC-4 Connectors

The MC-4 connectors are bulkhead connectors that allow you to connect the solar panel quickly. There is one for each polarity.  They are held in place with a plastic nut. The metal connector does not have to be soldered but it should be.  There are instructions online that detail the process. It requires a special tool to disconnect the solar panel.  This can be kept on the side of your mount with a lanyard.

These connectors are attached from behind the PVC panel. Drill (2) 1/2” holes in the bottom left-hand corner and insert the connectors through the PVC panel. Secure them with the plastic nuts.

This allows us to connect the solar panel quickly and keeps the cables out of the way.

The SAE cable is also mounted beneath the PVC panel. It too provides a way of connecting the SAE cable that goes to the RV.

Install it on the right side so that the red and black wire can reach the Charge Controller.  Drill a hole just large enough to allow the connector to fit inside the hole, attach with self-tapping screws.

Step 7 – Installing Solar Tracker

The Solar Tracker has a remote sensor that exits the Solar Tracker Module via a single cable.  Because we want to be able to disconnect the solar frame from the tripod quickly, we need to make the sensor easily detachable.

A quick release knob would make it a lot faster to remove the sensor for transport. There is a turn knob with a quick release mechanism but they are expensive and hard to find. A simple knurled nut will suffice

Step 8 – Wiring Diagram

Step 9 – Mounting Solar Panel

The solar panels are attached to the solar mount via M5 x 10 mm turn knobs, a washer, and a t-nut. Place a flat washer on an M5 x 10 mm turn knob and pass it through the solar panel grommet. Put on the top (2) and then slide it in the t-slot of the top bar. When the panel is in-place turn the knobs and tighten them. You may need more than one washer to get it to tighten. Velcro strips would be a better means of quickly attaching the panel.

Step 10 – Basic Operation

Please confirm that you have correctly connected all the components together. The solar panel MC-4 connectors can only be inserted one way and the same with the SAE connector that goes to the RV.

If your RV was prewired for solar it may have a Zamp connector on the side, if so you will need to also connect the SAE adapter to reverse polarity. Zamp connectors are the opposite polarity of a typical SAE connector. The adapter you purchased will correct for that.

You can test your system by pointing the solar panel toward the southern sky. The look angle will be determined by your latitude and time of year. There are online sources you can refer to get a better idea. For test purposes all we care about is facing south and that we have enough sunlight to trip the sensor.

When the solar panel is connected to the MC-4 connectors and the cable to the RV is plugged into the SAE socket power is being applied to the Charge Controller. The Charge Controller, via the “Load” terminals, sends 12vdc power to the Solar Tracker Module.

The Sensor, mounted at the top of the mount detects the amount of light and direction and sends a signal to the Tracker. The tracker converts that small signal to an amplified output to the gear motor. The direction the motor turns will be dependent on the Sun’s position. When the sensor is back in alignment with the Sun the signals will cancel out and the motor stops.

This system does not have built-in limit switches.

Step 11 – Disassembling & Storage

To disassemble your solar tracker start by unplugging the SAE cable from the RV. Then remove the MC-4 cable using the special tool. I recommend keeping the MC-4 tool attached to the mount using a lanyard, Velcro or magnets. Coil both cables and attach them to the solar mount. A Velcro loop would work nicely.

The sensor can be removed easily if you used a turn knob to mount it. Simply remove the knob, coil the cable with the sensor and attach it to the PVC panel.

The solar mount can now be removed. Loosen the M6 nut (you will need a wrench) and remove it and the lock washer. Loosen the (2) M5 x 15 mm turn knobs holding the “L” bracket and slide it away from the motor.

Now unscrew the 1/4-20 turn knob you installed on the bottom “L” bracket, be sure that it clears the hole on the other “L” bracket. Simply lift the entire mount and store it. If space in your RV is at a premium then you can separate the solar panel from the solar mount and stow the panel under your mattress or on an interior wall. You could also continue to break the system down by separating the two sections. The PVC panel and tripod mount can be stowed as one and the tripod folds up very compactly.

This is what makes this system so unique, you can break it down or build it back in a matter of minutes. This might be useful if you are transiting and won’t be setting up your solar for a few days.

Parts Needed For This Build

The following items are all available through Amazon via my affiliate links. Please note that you can purchase these items from any source you like. You may find certain items for less.

The tripod and the mount are critical to this build because of the mounting plate. You can substitute the PVC hair-cell panel with any watertight enclosure provided it stays within the dimensions of the tripods mounting plate. Remember an enclosure will add weight, height, and cost.

View parts list here.