Jack_Campin
Oud Junkie
Posts: 333
Registered: 5-6-2007
Location: Scotland
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3D-printed rosettes
Anybody tried 3D-printing oud rosettes, or the even more complicated rosettes for baroque guitars?
Dunno anything about the acoustic properties of printing resin but it doesn't seem like a very critical problem.
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jdowning
Oud Junkie
Posts: 3485
Registered: 8-2-2006
Location: Ontario, Canada
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About 18 months ago I purchased a relatively low cost 3D printer as a tool to learn more about CAD (Computer Aided Design). The Creality Ender 2
printer comes as a kit for self assembly - taking about 30 minutes to assemble. It has a small footprint so does not take up a lot of bench space has
a heated bed and a print volume of 150 x150 mm by 200mm height. Having run a number of test prints - some to make parts to improve on the original
printer design - other priorities have got in the way so the printer has been put on one side for the present time - perhaps to be further explored as
a winter project.
I did have in mind printing out some lute or oud rosettes from first principles using free software to create the files to input the printer. There is
an online community of 3D printer enthusiasts that post free developed CAD programs for a whole range of print projects - including this one for an
oud rosette!
https://grabcad.com/library/sound-hole-rosette-for-new-project-an-ou...
I have yet to run a test print of this rosette but will do so once I have time to get my printer up and running again.
There is a wide range of plastic filament materials available for 3D printers some impregnated with wood or metallic powder to give the appearance of
wood or metal. There is also a filament that will print a model in wax that can then be used for casting solid metals by the 'lost wax 'process. See
here for a description of the full range of filament materials. Not every printer can handle all of the materials but there is scope for some
interesting possibilities.
https://all3dp.com/1/3d-printer-filament-types-3d-printing-3d-filame...
Note that the rosette does not significantly affect the sound hole acoustics of an oud or lute compared to an open sound hole as the mass resonant
airflow across the sound hole is restricted to the outer perimeter of a sound hole. This excellent recent research paper from MIT exploring the
acoustic effect of sound holes in violins but also including some related investigation of lute sound holes provides the complete technical analysis
but, like all good published research work, summarises the conclusions of all the physics and mathematical proofs in a straightforward manner that can
be understood by those (like me) who are not physicists.
https://royalsocietypublishing.org/doi/full/10.1098/rspa.2014.0905
I do not know if a baroque guitar '3D' rosette will have some effect on sound hole acoustics (by modifying the apparent depth of the sound hole and
hence the Helmholtz resonance value). Another potentially interesting topic for experimental investigation no doubt!
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Dr. Oud
Oud Junkie
Posts: 1370
Registered: 12-18-2002
Location: Sacramento, CA, USA
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Just to get your terminology straight, the 3-D printer is a CAM (Computer Aided Manufacturing) system. The design input to the 3-D printer is the CAD
system. Two different animals.
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Dr. Oud
Oud Junkie
Posts: 1370
Registered: 12-18-2002
Location: Sacramento, CA, USA
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I don't like the machined appearance of laser cut roses. They are too perfect. The hand cutting produces irregularities that gives the rose character
and is witness to the hours spent sawing out the pattern.
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jdowning
Oud Junkie
Posts: 3485
Registered: 8-2-2006
Location: Ontario, Canada
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Most affordable 3D printers produce a three dimensional print in thermoplastic others (relatively more costly) print in greater detail in light cured
resin. Both types build up a print layer by layer in 'slices' - an additive process.
The cheapest entry level printers currently cost around US$200 but industrial quality printers can cost thousands. My printer is the cheapest I could
find at the time (about 18 months ago) that had good reviews and which could handle a variety of thermoplastics (see my previous post). To test the
printer I have made a number of prints from .stl (stereolithography) files prepared by others and freely available on line. The input files must be
further processed with slicing software (I have used CURA) prepared on a PC and then loaded on to a micro SD card that is inserted into the printer to
run the print. It takes some experience to select the optimum parameters for producing the best print from the printer as well as setting up the
printer mechanically for best performance.
The Creality Ender-2 printer (sold as a self assembly kit of parts) has some design imperfections that may be overcome thanks to support groups on
line. For example one of the decorative plastic strips on the vertical column had to be removed as it fouled a screw on the back of the X axis module
disturbing free movement and so adversely affecting print quality.
As an example of the complexity of print that is possible the attached image shows a roller bearing printed in one piece. It is not perfect due to
less than optimum mechanical set up (that may be improved upon by trial and error) but it does rotate as designed.
Since the preliminary trials 18 months ago the printer has been set aside due to other work and life priorities so there will be some re-learning of
the process to go through. Once I can find the time - hopefully as a winter project - I plan to try printing oud/lute rosettes starting with scanned
2D line drawings and converting these to 3D using free TinkerCAD software just to see what might be possible - good or bad - at lowest cost. This
project will be reported as a separate topic on this forum.
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SamirCanada
Moderator
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Registered: 6-4-2004
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Hi John I have been following with interest as you know.
I stumbled on this YouTube video of someone making oud rosettes with a 3d printer I believe.
https://youtu.be/HS8CF4BQUcQ
@samiroud Instagram
samiroudmaker@gmail.com
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jdowning
Oud Junkie
Posts: 3485
Registered: 8-2-2006
Location: Ontario, Canada
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Thanks Samir
Very interesting and it shows what can be done. The 3d printer in this case is a Dremel product - fully enclosed and ready to go 'out of the box' -
very nice printers (and tempting!) but costing in the CAN $900 to $2,000 range. My challenge is to see what can be done with an entry level printer
kit - no doubt less precise - costing CAN $250 or less!
The use of 'Auto Desk 123 Design' free CAD design software shown is interesting so I hope to give that a try in future. Also confirmation of my
current approach in using B/W 2D images as a successful start point to printing is encouraging.
I also liked the decorative use of the patterns left by intentional filament layering in the printing process.
For an oud it is beneficial to allow the main rosette to be removable to enable small internal repairs through the sound hole wiuthout need for
removing the sound board (impossible for a European lute with 'cut in' rosette). I have yet to test if there are thermoplastic rosettes that can be
successfully glued in place with hot hide glue. PLA softens at around 70°C so might just be a possibility with hide glue at 64°C max? We will see!
No doubt synthetic non traditional glues might be used if a rosette is to be a permanent fixture.
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