Turning Recycled Skateboards Into a Bluetooth Boombox

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This instructable shows how to make a portable bluetooth boombox from twice-recycled skateboard wood. I managed to use every part of the skateboard in this DIY speaker build. The front panel is formed from reclaimed skateboard wood, the handle of the speaker is made from skateboard trucks, and the feet are made from skateboard wheels and bearings.

Also, be sure to check out the full build video for the boombox -- I tried to include all the details here, but some things are better explained via imagery than in words :)

You could easily modify the design to make the front panel from a hardwood like walnut, or from MDF or plywood (and paint it to match the rest of the speaker). The rest of the enclosure is made from MDF, so we’ll build that first, then deal with the skateboard wood front panel in the next section.

I used Dayton Audio kit parts for the electronics. It has a 2x50w Bluetooth amp, which is driving two Tang Band 5” W5-2143 full range speaker drivers. It is battery powered, with great battery life, and most importantly, sounds amazing!

ENCLOSURE CALCULATIONS: The parameters and volume calculations for the Tang Band speaker and 2.5" ports are in the picture attached above, and on my blog: https://goo.gl/ZYGm3f

Step 1: Gather the Materials

SPEAKER PARTS USED IN BUILD

• Bluetooth Amplifier Board: https://goo.gl/UgQ4wq

• 5” Full-Range Drivers: https://goo.gl/4WXUtJ

• Battery Charger Board: https://goo.gl/1w3C74

• Li-ion Batteries: https://goo.gl/LUPbzs

• 19V Power Supply: https://goo.gl/t2sZwB

• “L” Brackets for Amp and Battery Boards: https://goo.gl/SQzwwQ

• Cable Kit (on/off. Volume, line input): https://goo.gl/XY6gcy

• 2.5” Ports: https://goo.gl/mQwhL2

• Female Power Jack: http://amzn.to/2H3oN0P (no solder) || http://amzn.to/2H3oN0P

• Sanding Sealer to prep MDF for paint: http://amzn.to/2IJv1nF

A huge shout out to KIRBY MEETS AUDIO for his help in designing the speaker enclosure and selecting the Tang Band drivers. His channel has a wealth of information on speaker design and speaker building, and his video production is top notch. Kirby Meets Audio channel link: https://goo.gl/8gFxnw

TOOLS FOR ELECTRONICS

• My favorite solder: http://amzn.to/2CNgjIF

• Quality Soldering Iron: http://amzn.to/2CKHoMC

• Blue Soldering Mat: http://amzn.to/2DboPCd

WOODWORKING TOOLS

• Cordless Nailer: http://amzn.to/2FJIsFW

• Ridgid Cordless Router: http://amzn.to/2pinfZL

• 90 Degree driver / oscillating saw: http://amzn.to/2FHqrbB

• Hole Saw Kit: http://amzn.to/2GztkIw

• RZ dust mask: http://amzn.to/2wM8F1t

• Bosch 18V cordless circular saw: http://amzn.to/2wcDgnN

• Bosch 18V cordless Drill & Impact Driver Kit: http://amzn.to/2BCI753

• Dewalt Table Saw w/ 32” Rip Capacity: http://amzn.to/2yQd2Fy

• Japanese Flush Cut Hand Saw: http://amzn.to/2yRa1Fd

• Dewalt 12” Miter Saw: http://amzn.to/2yQRgS6

• Forstner Bits: http://amzn.to/2Bgv863

Step 2: Cut List for Speaker Enclosure

Here is the cut list for a boombox that is 26”

W x 10” H x 12” D. You can cut from the wood of your choice, hardwood, MDF, or plywood, but MDF is a good choice for acoustics and workability, so I used MDF. Note that for mitered pieces (e.g., with 45 degree cuts), the dimensions are for the longer side. Also, you could easily build this with butt joints by subtracting ¾” (thickness of the plywood) from the sides of the lamp and base that are perpendicular to the ground.

½” MDF:

- 28”x12” front panel (backer for skateboard wood, will be trimmed to 26”x10” after glue up)

- (2) 26”x12” – bottom and top panels

- (2) 9”x12” – side panels

- (2) 9”x11” – baffles

- (2) 9”x10.5” rear/back panels

- (4) ¾” x 1.5” mount

Acrylic control mount panel – 4”x9”

Skateboard wood front panel – 26x10” (more on this in its own section)

ENCLOSURE CALCULATIONS: The parameters and volume calculations for the Tang Band speaker and 2.5" ports are in the picture attached above, and on my blog: https://goo.gl/ZYGm3f

Step 3: Build the Boombox Shell

Only the front panel is made

from skateboard wood. You could easily modify the design to make the front panel from a hardwood like walnut, or from MDF or plywood (and paint it to match the rest of the speaker). The rest of the enclosure is made from MDF, so we’ll build that first, then deal with the skateboard wood front panel in the next section.

See the above video for an animation showing the general assembly process (note that the video doesn’t show the holes for the ports.

1. Use wood glue and brad nails to assemble the bottom and top panels, side panels, baffles and rear/back panels in the manner shown in the above video. It is easiest if you assemble the bottom, top and sides first, then slide the baffles in (using a half inch MDF scrap as spacer in front to ensure a tight fit for the rabbit you’ll cut in the front panel). After nailing in the baffles, then you can glue and nail the back panels in.

2. Cut 2.5” holes for ports in the back panels

3. Cut 5/16” holes in the top of the enclosure for the threaded LED indicators that come with the Dayton Audio kit. To make it easier to screw on the nut to the threading on the LED holder from the inside of the speaker, you’ll also want to use a 1-3/8” Forstner bit on the inside of the top panel to remove some material on the inside of the panel, opposite the holes for the LED indicators. (Note – if you don’t have a right angle drill, you probably want to drill holes for the LED indicators before gluing up the speaker enclosure.

Step 4: Build the Skateboard Wood Front Panel

I received offcuts of stacked skateboard plywood from Focused Skateboard Woodworks, a company that specializes in making furniture from reclaimed skateboard wood. Basically, I broke them down and squared them in a similar way that you would for a cutting board made from scrap lumber. First I cut long 2” strips of stacked plywood on the table saw. Then I glued these 2” strips up to make a large panel, roughly 28”x12” (although some ends were jagged on top). I made sure to leave a small gap so the MDF back panel was slightly proud of the skateboard wood on one side and the bottom of the glue-up. This way, the MDF would give me a straight edge to cut against on the table saw. See the video for more details on the glue-up process with the skateboard wood and MDF.

Once the glue dries, take the panel to the table saw and trim it to the 10” height (don’t trim the sides to size yet, though). Then run the panel through the planer to flatten out the top panel. You could also do this with a belt sander or a router planning jig. After flattening the panel, go back to the table saw and cut the sides so you have a 26” wide panel.

Now flip it over and get a rabbiting but with a 1/2" cut width, and set the depth of cut to 1/2" on your router (the same as the thickness of your MDF. Cut out a 1/2" rabbit on the back of your speaker panel, which will remove all of the MDF from the rabbit. By doing this, the skateboard wood front will sit flush against the speaker enclosures, and the MDF will be hidden (and sit flush against your inner baffles when assembled).

I also used a 1/4" roundover bit on my router to round off all the edges of the front panel and the enclosure. This is optional, but I think it gives it a nice finished look.

Next, you’ll cut holes for a recessed mount for the 5” Tang Band speakers. I used a DIY router circle cutting jig to cut perfect circles (see this video for an easy to make circle jig: https://youtu.be/GwF7fwtUr80 ). I first made a few passes with the jig, starting outside to in with a ¼” router bit, to create a recessed circle about ¼” deep and the outer diameter of the speaker (check your speaker specs for exact dimensions). This creates a recessed lip for the rim of the speaker to be attached to. Then I used a drill and jig saw to hog out the 5” wide inner circle, all the way through the front panel, to accept the speaker driver. Repeat this for both speaker holes.

Step 5: Finishing and Painting

I finished the front panel with matte polycrylic using a roller, and used Montana spray paint to paint the MDF enclosure. Since you are using different finishes, I recommend applying the finish to the front panel, and the paint to the MDF, before attaching them together.

Step 6: Acrylic Control Panel

I used a piece of scrap 1/8” smoke grey acrylic for the 4”x9” control panel, which covers the gap in back between the two speaker enclosures. Carefully drill holes in the acrylic back panel for the parts from the Dayton audio kit (the on/off switch, the volume control, and the line-in jack). Also, you’ll want to find a female threaded power jack, and drill a hole that fits this jack.

Next, use wood glue to install your four MDF control panel mount pieces at the corners in the back gap between the two speaker enclosures. Place the acrylic panel against the MDF mount pieces, and drill holes to accept screws. You want to use screws so you can access the electronics behind the control panel if need be.

Step 7: Making the Handle From Skateboard Trucks

I found a pair of old skateboard trucks on Ebay for $1 and decided they would make a good handle. I simply used an angle grinder with metal cutting wheel to cut the axels (e.g., the parts extending out that look like bolts) of the trucks, and then used a flap disc to smooth down the ends. Putting the two trucks together so they are touching, then makes for a nice handle. I don’t have welding gear, but it would be very cool to weld them together. We’ll attach the trucks later.

Step 8: Making the Feet From Skateboard Wheels

The feet are made from four skateboard wheels and four bearings (you could just use a washer instead of the bearings). I used a disc sander to sand down one side of each wheel so it was flat. Getting them the same height took a bit of back and forth, and trial and error, but eventually you’ll get it. You could also use a clamped-down belt sander if you don’t have a disc sander.

Step 9: Electronics

All the electronic components (other than the speakers) go in the 4” wide compartment between the two speaker enclosures. The Dayton Audio parts I listed are really easy to install – plug n’ play for the most part. I do recommend soldering the speaker wire to the speaker, and soldering the power wires to the power jack in the control panel. Other than this, just follow the picture instructions that come with the Bluetooth amp board, and plug in the LED indicators, on/off switch, speaker wires, power wires, line-in jack, and volume knob where indicated in the instructions.

The battery charging board I linked to also makes power and charging very simple. You just use the included plug n’ play cables to plug it into the Bluetooth amplifier board, and that is it. When the power supply is plugged in to power the amplifier board, the control logic knows to charge the batteries and will control the charging for you. The amplifier board also knows to switch to battery power when you unplug, and handles all this for you.

Step 10: Assemble Everything

After hooking up all the electronics and testing to make sure everything works, it is time for assembly.

1. Glue the front panel to the speaker enclosure

2. Screw the ports in to their holes in the backs of the enclosures (make sure to pre-drill all holes)

3. Screw in the skateboard feet to the bottom of the enclosure, using the bearings like washers for the screws.

4. Screw in the trucks into the top of the speaker using the mounting holes in the truck bases, so that the tips of the trucks are touching to form a handle.

5. Screw in the speakers

6. Screw in the acrylic control panel