Introduction: Solar Powered Disco Bike Trailer

About: I used to work for, now I just make stuff. // follow me to see what I'm up to:

Building this Solar Power Bike Trailer was probably the most fun I've ever had during a build. (Really anytime I get to use a cut-off wheel on an angle grinder, I'm pleased.) Furthermore, I'm excited for the years of fun I will have with this trailer, towing a portable dance party behind my bike! My friends and I will have the best pedal-powered dance party in the streets! Be sure to join us if you ever see us riding around :)

Step 1: Materials and Supplies

Parts List:

(1x) Bike Trailer (I found mine on craigslist)

(1x) 12V/4Ah Sealed Lead Acid Battery Radioshack 55034004

(1x) +5V Fixed Voltage Regulator 7805 Radioshack 2761770

(1x) Pioneer TS-D1720C 6.75" Component Speaker Package Radioshack 55032192

(1x) Pioneer TS-D1720C 5.25" Component Speaker Package Radioshack 55032190 (I ended up only using the speakers, and not the tweeters from this package)

(1x) 5W Solar Panel Radioshack 2770112

(2x) TriColor LED Strip Radioshack 276-339

(1x) Topping TP20-MK2 MKII TA2020 Class T-AMP Digital Stereo Amplifier

(1x) Auvio Bluetooth Reciever with Near Field Communication Radioshack 150476

(1x) Small PCB Radioshack 2760148

(1x) Sunforce Charge Controller Radioshack 2770107

(1x) 50-Ft. 16-Gauge Clear 2-Conductor Speaker Wire Radioshack 278-1267

(1x) 22 Gauge stranded wire, multiple colors Radioshack 278-1224

(1x) black electrical tape Radioshack 64-2373

(1x) Size M Panel-mount Coaxial DC Power Jack Radioshack 274-1563

(1x) 3/16" battery terminal connectors Radioshack 64-3132

Additional Materials/Tools:

Wire Cutters/Strippers Radioshack 64-224

Rosin Core Solder Radioshack 64-009

Soldering Iron Radioshack 55027897

Razor Blade Cutting Tool

Power Drill


Screws Locknuts/nylon nuts (for areas of high vibration) and regular nuts, and bolts - 2" and 1"

Small L-Brackets Screwdriver

felt (for mounting components)

marking pen

metal file

wire crimper Radioshack 64-225

black spray paint

spray adhesive reflective fabric

double sided foam tape

thin vinyl tubing

1/4" plywood for mounting LED lights **I designed this project to hook up to the Tricolor LED Strip Control mechanism constructed in the Ultimate Night Bike build.

Step 2:

Here at the pier we have access to some super rad tools. I used the METABeam 48" Laser-Cutter to cut the 3 panels I designed in Adobe Illustrator. I used 1/2" plywood for the 3 main pieces that would make up the body of this trailer.

Step 3: Test Fit Your Panels

I designed all the parts to just zip-tie into place. This way, if I ever wanted to use the trailer without it in Disco mode, it would easily revert to it's former state. Hooray modularity!

I fit the zip-ties to the trailer bars, and then snipped the ends. I noticed that I was going to have to cut the middle trailer bars to make room for the speakers.

Step 4: Angle Grinders Are Fun!

I used an Angle Grinder with a cut-off wheel to remove the middle bars on the trailer. Thanks for the help with the photos Jon!

Step 5: Paint the Side Panels

I sanded the lasercut panels, and then sprayed the insides with black spray paint.

Step 6: Adhere DISCO Fabric

Scoochmaroo gave the Instructables folk a ton of awesome DISCO fabric from BetaBrand, I made these pieces fit to the wooden panels from scraps I found around the lab.

Adhering fabric to wood is usually pretty simple, and there are tons of ways people have figured out to bond the two - but for this project I just wanted to use some spray adhesive. Spray an even coat to both sides, allow to tack, and then bond the two together.

Step 7: Trim Excess Fabric

I used a rotary cutter to trim away excess fabric, but to wrap it around the edge, I left about a 1 1/2" seam allowance all around the outside.

Step 8: Tack Down Edges

Fabri-Tac is awesome, albeit a bit messy. For future use, I suggest gloves. I glued down the sides over the edges of the cut edge of the panel. I cut slits in the fabric to make it easier to tack down around bends and curves.

Step 9: Mount the Tweeters

I cut a small hole in the fabric to run wires through the tweeter holes, and then used the mounting hardware to screw the tensioner into place.

Step 10: Mounting Larger Speakers

I cut a small circle and slits in the fabric to make room for the larger speakers. Using Fabri-Tac again, I glued down the excess fabric to wrap around the edges. To mount the speakers into place with their face plates - gently pop out the mesh with your thumbs.

Step 11: Breaking the Fabric, and Using the Mounting Hardware

After I had skinned all the panels, I needed to get to my laser cut holes. I used an Awl to break through the fabric. Awls are AWESOME! and I used them a lot in this project.

Secure the Speakers with the hardware that came with the kit, and then re-attach the speaker mesh.

Step 12: Connect Speakers to Passive Crossover Units.

These units come with their own passive crossover units! Which is great! It makes it really easy to wire up. I made a dedicated Left Channel from the Amp to the left side, and a right channel from the amp on the right side.

Step 13: Laser-cutting the Light Panels

I wanted to have off-set LED panels, that would throw light on to the reflective fabric. I went into Adobe Illustrator and designed a form that complemented my existing structure, and laser cut it on an Epilog laser cutter using 1/4" plywood.

Step 14: Painting the Light Panels

I looked around to see what colors spraypaint were in the lab, and found these nice soft blues and silvers - it was a perfect accent to the already reflective fabrics I was using.

Step 15: Illuminating the Laser-cut Light Panels

I chopped up some of the tricolor LED strip into small sections. The LED strip from Radioshack is really easy to work with because there are clear cut lines, and solder junctions, and directional arrows that tell you how to use their product.

I split the strip into going 2 directions, with 3 sections on each side - and then wire it to one common junction point that would receive signal from my bike basket control unit.

Step 16: Attaching the Light Panels

I drilled a covert wire-chase for the LED wires to get threaded through, and mounted the panels using 2" machine screws, nuts, and vinyl tubing to act as thin compression washers on the bolts. This was a technique I came up with when I needed to make vibration-sensitive electronics for a xylophone, and have used this countless times since then.

Step 17: Creating the Solar Panel...Panel. :)

Using the same process as before, I sanded, painted, and then skinned the top panel of my laser cut wood, this part would be the top of the trailer.

Step 18: Mounting the Solar Panel

I used some machine screws and some nuts to fix the solar panel to the top panel. I used an awl through some more felt to make sure that the panel wouldn't vibrate around while the trailer was in motion.

Step 19: Make Power Connections

I wanted an easy way to connect/disconnect the battery from charging, if I needed to. I used a screw-terminal junction, and battery blades that would just slip-connect to the 12V battery.

Step 20: 12V -> 5V for Bluetooth Receiver

The bluetooth receiver for the speakers needed to be connected to a 5V power source, but I was using a 12V battery. Using a 5V regulator, I stepped down my current from 12V to 5V. I snipped the cord from the DC adapter and wired it directly to the regulator. It worked great!

Step 21: Wiring the Amplifier

The amplifier came with a 14V DC Converter, but i tested it with a 12V power supply and it worked fine. I hooked it directly to the 12V battery.

Step 22: Receiver -> Amplifier

Using an Stereo->RCA Cable, I wired the the receiver to the amplifier, and ran long lengths of speaker wire from the amplifier. I would later trim these wires down, after I figured how long I needed them to be to reach the passive crossover units near the speakers.

Step 23: Putting It All Together

Using double-sided foam tape, I mounted the charge controller, the bluetooth receiver, the amplifirer, and my charge circuit to the underside of the solar panel-panel :)

Step 24: Light Control Port With XLR Jack

I ran all of the LED light strip wires to the underside of the trailer, and installed an XLR Jack for them to receive signal and power to. This way, the light control mechanism in my bike basket can power and control the lights, without drawing power from the speaker's battery.

Step 25: Tidying Wires

Using some adhesive velcro, double sided foam tape, and cable ties, I was able to mount all the wires to the inside of the panels, and secure the battery into place.

Step 26: Addressing Vibration

Before all of the zip-ties were too tight, I crammed some thick chunks of felt in between the bar and the wood. This helps with chatter from the road and vibration from the speakers.

Step 27: Make an XLR CABLE

I was initially braiding cables to make long linkages from my bike basket to the bike trailer. But then DJ taught me a really cool way to make your own custom cables. I took 3 pieces of wire, chucked them in a drill, and extended them to the length I needed before snipping. The cable from the basket to the trailer is about 7 feet.

Makin' cables with DJ in the #P9Workshop

A video posted by (@instructables) on

Step 28: Turn Up Your Speakers, Your Woofers and Your Tweeters

Go out and bump it!

We had a ton of fun making this project, but even more fun having impromptu dance parties along our route!

Can't wait to see who else makes similar projects!