DHB-01: Minimalist Electric Violin

DHB-01 is a 3D printable electric violin named after ダークネスハウリングブレイザー. This electric violin is ideal for those seeking a modern twist on their classical instrument.

Watch Nataly Merezhuk's DHB-01 performance:

1. Printing Parameters

• Recommended material: Carbon-Fiber PLA
• Wall thickness: 2mm
• Infill rate: 40%
• With support and brim enabled
• Due to the filament's abrasive nature, a hardened steel nozzle is also recommended

Note: Ensure no support is generated inside the tube area. For me, this means the Support Overhang Angle setting shouldn't be below 80°; otherwise, debris removal becomes difficult.

I prefer printing large objects with a 1.0mm nozzle and 0.5mm layer height.

Print lines won't be an issue, as we'll sand the surface. And it's satisfying to complete the entire print in about 8 hours. However, this is just my preference; your mileage may vary. 

2. Post-Processing

Use 5-minute epoxy to bond the carbon fiber rod, neck, and body together. (Refer to the full list of standard parts at the end of the page.)

2.1 Sanding

Start with a half-round file, transitioning to 180-grit sandpaper. The goal is to flatten the surface as much as possible. At this stage, you might still see some print lines, seams, and crevices, but we'll get to those.

2.2 Priming (optional)

After sanding, some areas will need putty, especially:

• Frequently touched areas like the neck and fingerboard
• Seams, notably between the neck and body
• The stair-stepping effect on the side and support scars at the heel

I've found UV resin to be the best option. It withstands wear from fingers and strings, also sands down easily. A thin coat can cure in 60 seconds under a UV LED.

Images showcasing the application process: 

• Fixing seams
  
• fixing support scars
  
• Fixing stair-steppings
  

Alternative: Consider the JB Weld SteelStick Epoxy putty. It's very strong and the color blends well with carbon-fiber black.

Not Recommended: Black wood filler or drywall compound, they didn't really work for me. Found them to be a bit too brittle and heavy. 

2.3 Painting (optional)

Repeat the above steps until satisfied. Apply black primer paint, followed by a round of sanding with 400-grit sandpaper. I use The Army Painter's MATTE BLACK primer, but other surface primers should work.

Safety Note: Use a mask and work in a well-ventilated area. If painting outdoors, avoid direct sunlight. Black paint can absorb heat, potentially deforming PLA at around 65°C (~150°F).

3. Tube Bending 

Bend the brass tube approximately 7cm (2.75 inches) from both ends:

• The chinrest end: Between 90-120 degrees, adjusted for comfort
• The body end: 90 degrees

Keep it close to the tuning pegs to minimize bow interference.

Note: To avoid kinking the tube (and compromising its strength), you can fill it with sand and use a pipe bending tool to steadily bend it to the desired position. 

All parts can then be glued using 5-minute epoxy. 

4. Hardware Installation 

4.1 False Bout (optional)

Insert an M4x6 heat-set threaded insert into the heel/nose. Secure false bout with an M4x10 screw. Gluing is an alternative. 

4.2 Pickup and Preamp (optional)

DHB-01 is designed for the Shadow SH 945 violin pickup & preamp, but it's just what I had around. If you're only after a silent practice violin and don't need the electronics, feel free to skip this step. 

If you can't get the exact same model or want something different, there are alternatives: 

• The bridge area accommodates typical under-saddle piezo pickups or piezo-embedded violin bridges
• You can then connect the pickup to an audio jack and choose your preferred signal processing, like an iRig or amplifier
• If you need to fit a specific preamp, you can modify the cavity using the included editable STEP file 

4.3 Strings, Tuning Pegs, and Bridge

When stringing the middle strings (D and A), pull a bit of extra length through the tuning pegs. Due to the proximity of these two pegs to the bridge, this prevents too many wraps around the pegs and keeps the strings from slipping off. 

A reference 3D printable bridge, set to the correct string height, is provided. (modeled after the OpenFab PDX EEV, a special shout-out to David, you rock! ;-)

For different pickups, ensure the bridge's feet height is adjusted for optimal string action.

5. Standard Parts

Below is a list of parts I used, with non-affiliated Amazon links:

• 1 ✕ 8mm carbon fiber rod (33cm) 
  https://amazon.de/gp/product/B0798QG4KC
  or lighter carbon fiber tube
  https://amazon.de/gp/product/B07S1TFSVV 
• 1 ✕ 9mm brass tube (30cm)
  https://www.amazon.de/dp/B07P84KSKV
  you'll also need a pipe bending tool, 
  e.g. https://amazon.de/dp/B08LSYPGKM
• 4 ✕ guitar tuners 
• 1 ✕ violin strings set 
• 1 ✕ self-adhesive EVA pads (for shoulder rest)
  https://www.amazon.de/gp/product/B01N9LYY90