James W. Meng

Home/Resume/CV -- VLNLAB -- Projects -- Abuse by the United States Government -- Writings


VLNLAB PRINT

BUILD -- PRINT -- DOWNLOAD

How can I start printing your instruments?

We've tried to make this as simple as possible. You'll need a large format 3D printer; the models available for download will, in principle, work on printers of any type given sufficient size, but the instruments were designed to be built from specific types of filament on a large-format, fused deposition modeling (FDM) printer, for which the only real options in the market today are RepRap type.

What printers do you recommend?

We designed these instruments on a printer that more or less started life as a gCreate gMax 1.5, but completely rebuilt it with a number of major refinements that addressed design flaws to vastly improve print quality and printing capabilities, which the manufacturers themselves now seem to have mostly addressed in their latest iteration. Nevertheless, there are a number of other options available in the market today at lower prices that are worth investigating; an eBay search for "3D printer 400x400" should help you find everything you need.

Alternatively, if you really know what you're doing, you could build your own: the RepRap framework and firmware are open-source, and a free weekend and about $300 in parts from sources like Amazon and OpenBuilds is all you really need to start printing - just be sure you don't skimp on quality for the stepper motors, stepper drivers, and extruder.

What filaments and other materials do you recommend?

In terms of filaments, you need to be sure of two things. First, because the top and back plates as well as the sides and fingerboard are printed standing vertically, you need materials that warp only minimally when cooling. This essentially means that only PLA and other highly-stable PLA hybrids are recommended. We obtained our best results - in terms of both fit/finish as well as sound quality - with ProtoPasta CFPLA for the tops, bridge and sides, and ProtoPasta High-Temperature CFPLA (HTCFPLA) for the backs, fingerboards, and necks.

For joining the parts, superglue (cyanoacrylate) is recommended. All fittings (tailpiece, chinrest, pegs, etc.) can be standard parts, though geared pegs or ukulele tuning machines tend to make life a lot easier. We recommend rope-core steel strings like D'Addario Helicore as they produce just the right amount of tension for a synthetic-material instrument: any less and both response and volume will be considerably reduced; any more - as with solid metal core strings - and you'll have a durability/longevity problem on your hands. Plan to cut off (use a thin hobby knife, or perhaps a small kitchen knife) the thread wound around the tailpiece end of the strings; this will give you a sizeable increase in volume and response.

What print settings should I use?

Top:
Print Orientation: Vertical
Layer Height: 0.2mm
Number of Perimeter Shells: 1
Extrusion Width: 0.5mm
Extrusion Multiplier: 100%
Infill Percentage: 90%
Infill Pattern: Rectilinear, angle offsets 45 & -45 degrees
Print Temperature: 230 C
Other Settings: we recommend a 2- or 3-layer raft to provide a stable build surface.

Back:
Print Orientation: Vertical
Layer Height: 0.2mm
Number of Perimeter Shells: 1
Extrusion Width: 0.5mm
Extrusion Multiplier: 100%
Infill Percentage: 75%
Infill Pattern: Rectilinear, angle offsets 45 & -45 degrees
Print Temperature: 230 C
Other Settings: we recommend a 2- or 3-layer raft to provide a stable build surface.

Fingerboard:
Print Orientation: Vertical
Layer Height: 0.2mm
Number of Perimeter Shells: 2
Extrusion Width: 0.5mm
Extrusion Multiplier: 100%
Infill Percentage: 80%
Infill Pattern: Rectilinear, angle offsets 65 & -65 degrees
Print Temperature: 230 C
Other Settings: we recommend a 2- or 3-layer raft to provide a stable build surface.

Neck:
Print Orientation: Fingerboard Joint Face Down
Layer Height: 0.2mm
Extrusion Width: 0.5mm
Extrusion Multiplier: 100%
Infill Percentage: 80%
Infill Pattern: Rectilinear, angle offsets 65 & -65 degrees
Print Temperature: 230 C
Other Settings: we recommend using only a single skirt to the model, with no spacing between the skirt and the model - this is intended simply to prime the nozzle and ensure optimal print quality.

Sides:
Print Orientation: Bottom Joints Face Down (Vertical)
Layer Height: 0.2mm
Extrusion Width: 0.42mm
Extrusion Multiplier: 100%
Infill Percentage: 85%
Infill Pattern: Rectilinear, angle offsets 75 & -75 degrees
Print Temperature: 230 C
Other Settings: we recommend using only a single skirt to the model, with no spacing between the skirt and the model - this is intended simply to prime the nozzle and ensure optimal print quality.

Bridge:
Print Orientation: Flat Face Down
Layer Height: 0.2mm
Extrusion Width: 0.4mm
Extrusion Multiplier: 100%
Infill Percentage: 70%
Infill Pattern: Rectilinear, angle offsets 75 & -75 degrees
Print Temperature: 230 C
Other Settings: we recommend using only a single skirt to the model, with no spacing between the skirt and the model - this is intended simply to prime the nozzle and ensure optimal print quality.