Headless Bass From a Mac Mini

Inspired by the art of cigar box guitar making, I thought it would be cool to make a headless bass guitar using a Mac Mini shell as the body.

I determined that a 32" scale would work best. I drew everything to scale using Adobe Illustrator on a good Mac I wasn't going to cannibalize, then printed it out at full size so that I may start building.

Supplies

1 - Mac Mini shell, gutted
1" thick Hard Maple for neck and body insert
Wood glue
Pre-cut and pre-radiused Fretboard material
Low-profile bass pick-up (I used a Flat Cat)
Volume and Tone pots
1/4" guitar jack
6150 fret wire and black Corian nut
fret markers and side dots
dual action truss rod
Headless bass bridge and headpiece (I used Hipshot's headless system)
Aluminum rod (for strap horn)

Step 1: Cut Glue and Rough Shape the Neck and Body Wood

I used 1" thick nominal hard maple and ripped it to 1.5" strips for the neck and body.

I first glued 4 pieces that were 44" long for the neck, using wood glue and lots of clamps.

I then glued 9" pieces on each side of the neck blank for where the wood would fill the Mac Mini shell.

Once the Maple was glued up, I ran it all through my planer to get the assembly down to the thickness I needed for the neck (the wood that fits in the shell is not as thick so I used a router to make the body section thinner.)

Next, I drew a centerline and routed a 1/4" wide x 3/8" deep channel for the dual action truss rod, extending the rout past where the nut will go so that you can adjust it later on.

I then used a forstner bit to cut the 2 arcs in the neck where it meets the body, then ran the assy. through a band saw to cut the taper of the neck - 1.75" at the top end, and 2.5" at the bottom where it meets the body

Step 2: Fretboard

Not having the tools to cut the fret slots and radius the fretboard, I purchased one pre-made from a luthier supply house in the US. This one is made out of Richlite and was very easy to work with.

Once I drilled and glued the mother-of-pearl fret markers into the fretboard, I ran it though a band saw to match the taper of the maple neck.

The fretboard was then glued to the neck using epoxy, as recommended for Richlite material. If you are using a different type of wood, regular wood glue is fine.

I cut and placed frets and shaved them down flush to the fretboard (I do this when the back of the neck is still square so I have a stable base to press and finish the frets).

Step 3: Shaping the Neck

Once the fretboard was glued to the neck, I ran both sides along my reciprocating belt sander to smooth them up.

Next I shaped the neck, headstock and neck heel using a variety of rasps and shaping tools, including a Shinto rasp (I recommend one of these to anyone interested in building guitars).

When shaping, it is good to have an existing guitar plus a profile gauge handy for reference. The trick is not to make the neck too chunky, but if you go too far in you may end up hitting the truss rod channel!

Step 4: Hardware and Bridge

To get the 32" scale length I needed, I had to add a block of wood to the back of the body when mounting the bridge. The bridge I used hangs over the body's end slightly as needed so that the instrument may be tuned.

I installed the headpiece and nut, then drilled through the body in 4 places to install the pickup, controls and 1/4" jack (some of the wood inside the body was cut back to make room for the internal wiring and tone pots).

I opted to use a surface-mounted pick-up so that the only holes I needed to drill into the body were for the wires.

Step 5: Metal Horn Rod

The body of a Mac Mini is so small, there was nowhere to mount the strap posts, so I had a machinist friend fashion a 8" horn rod out of aluminum with an internal thread to hold a strap post, and an external one to insert into the body (I used a threaded insert in the body).

Step 6: Finished Product

The bass is very light (about 4 lbs.) and has a nice warm sound, thanks to the aluminum body.

Thanks for looking - and happy playing!