Prototyping a. Playable Ukulele. Rabea Baroudi

Transcription

1 Prototyping a Playable Ukulele Rabea Baroudi

2 Contents 1 Scenario 2 Goals & Motivators 3 Research & Planning 4 Implementation 5 Evaluation 6 Analysis 2

3 1 Scenario Design Challenge The UX Prototyping (HCDE 451) class at the University of Washington s final project was to use at least two of the prototyping techniques that were previously learned in the course (e.g., paper prototyping, laser cutting, 3D printing, video prototyping, wire-framing). The only requirement was that for whatever product created, it must be evaluated and analyzed in terms of how it satisfies at least one of the three design goals and motivators: desirability, feasibility, and usability. I decided to model and build a playable Ukulele. It was mainly created using 3D modeling and printing techniques, as well as laser cutting and paper prototyping. Timeline The class had two weeks to ideate, plan, and execute the projects at the end of the Winter 2018 quarter. All projects were showcased on March 8th,

4 2 Goals & Motivators Desirability Creativity Customization Low Production Cost Usability Durability Functionality Quality Assurance Feasibility Time Assembly Manufacturing 4

5 3 Research & Planning Initial Research Initial research was conducted at first to undestand the different parts of the ukuleles and how they are put together. Ukuleles come at a wide variety of sizes and shapes, which affect the sound and pitch. kalabrand.com After listening to different ukuleles played online and personally testing some at a local music store, I decided to model a soprano ukulele. The soprano was also the largest ukulele size that could be printed without having to slice it in terms of its width based on the 3D printer bed sizes availabe. 5

6 Prototyping Techniques 3D Modeling: (1) the main body including the the neck and headstock (excluding the top face), (2) the top face, and (3) the bridge were designed using SolidWorks and printed at Area 01 s Dabble Lab in Maple Hall. Laser Cutting: Braces were laser cutted out of wood and designed on Rhino 3D. The top face of the body was rastered using a laser cutter. The designs were created using Adobe Illustrator. Risk Factors Due to time constraints, the tuners (and strings) were purchased. The tuners had to be purchased before creating the headstock to determine the diameter of the holes as well as figure out the weight distribution (i.e. helping determine the fill density of the printed parts). 6

7 4 Implementation Preliminary Ideation Prototype To get a sense of size, weight, and stability of the prototype, a model was created out of cardboard. The paper prototype not only reduced the amount of time spent trying to research the information online and calculate/guestimate it, but also reduced the probability for errors at a low cost. 7

8 Sketches & Calculations The most challenging portion of the design process was making sure all of the calculations were accurate in order for the product to function properly (easy to handle and accurate pitches) and be durable. 8

9 Fret positions were calculated using StewMac s online fret position calculator. The average soprano s scale length is 33cm and has 12 frets, and this information was inputed into the calculator which provided me with the measurements for each fret size. For the fret position bars (separating each fret), the diameter measurements were found to be between 1-3mm online through research. Measurements vary by personal preference and the string height from the fretboard (the averag diameter was used: 2mm). 9

10 3D Modeling Using Solidworks, the ukulele was modeled in three separate parts (excluding the tuners an strings, which were purchase): (1) the body, neck, and headstock, (2) the top face of the body, and (3) the bridge. The top face of the body was printed separately to avoid using supports inside the body as well as be able to raster it separately with ease. 10

11 Preparing 3D Print Files Originally, the plan for printing the ukulele was to print the main build as one piece using Maple Hall s Leapfrog XL 3D printer. However, the printed ended up being out of order and I had to use the FlashForge Creater Pro 3D printers, which only had a printing bed allowance of 226x144x150mm. As a result, I had slice the part into three pieces using Flashprint. 11

12 Preparing 3D Print Files The STL parts (exported from Solidworks) were imported to Simplify3D to prepare the print files. As wooden PLA filament was used for the ukulele, temperature settings had to be adjusted (platform: 60 C, extruder: 195 C). Moreover, the number of shells had to be increased as well as the infill percentage due to how thin the model was, in order to ensure its stiffness and durability. The four large parts took between 6-8 hours to print, and the bridge took about 20 minutes. 12

13 Wooden Filament & Print Setting Adjustments Prior to this project, I had never printed using wooden filament. As I was unaware of the filament s temperature requirements, I had to adjust the settings a couple times after some of the parts failed. 13

14 Rastering a Custom Design In order to raster a custom design on the top face of the body, I exported the sketch from Solidworks and imported it into Adobe Illustrator. There, I designed some illustrations as well as obtained some from my classmates. I then used 1-Touch Laser Photo to prepare it as a wooden image raster file. 14

15 Assembly Superglue was used to assemble the ukulele. Wooden braces were laser cut and used for support in addition to the sound enhancement qualities they add to ukuleles and guitars in general. 15

16 End Product In all, the product was built and assembled with 5 3D printed parts, 7 laser cut wooden braces, tuners, and strings. 16

17 5 Evaluation Satisfaction of Goals In terms of desirability users who tested the prototype particularly liked the ability to customize the model and thought it was well designed overall. Moreover, this ukulele had a low production cost, making it desirable by users. It was built using g of wooden filament, costing about $6 (the strings were purchased for $7 and the tuners for $10). Designing and 3D printing the tuners would have further decreased the cost of the model and hence increased desirability. 17

18 In terms of usability, users found it to be sturdy and durable. However, while the ukulele did project a loud sound, the pitch of the notes were not always accurate. This was probably due to the holes not stopping the string at exactly the length it should have (nut to saddle breakpoint). An elevated block that curves the strings downwards for example could have been a better design to prevent this error. More time could have also been spent looking at fret sizes and ratios (i.e. consulting more than 1 website calculator) to ensure the error was not due to those measurements. In addition, one of my testers who is an experienced ukulele player, suggested trying to use different strings as that may be part of the lack of pitch accuracy. Lastly, based on feasibility, the model was effectively executed based on the resources available and the time frame provided of theproject. Printing it using a a larger printer (i.e. not slicing the main part into three) would have made it as well even reduced the production and aseembly time. 18

19 6 Analysis What Worked Well Overall, participants at the showcase found the prototype to be sturdy and liked the product s customization, overall design, as well as functionality. Participants also expressed that printing the top face as a separate part was not only well planned to avoid removing the supports that would have been formed inside the body, but also to prevent having to re-print the ukulele if an error was committed when rastering the design. 19

20 Improvements After users tested the prototype, the main areas of improvement centered around the pitch accuracy of the model. This may have been due to the bridge s design, fret ratios and/or the strings used (see Evaluation). Some participants also commented on how the headstock was a little heavier than anticipated or desired due to the weight of the tuners. The Next Iteration... For the next iteration, I would focus trying to (1) improve the pitch accuracy (by redesigning the bridge, consulting more than one fret measurement calculator, and make sure the pitch is accurate, use different strings), (2) 3D print the tuners as well so the weight isn t as heavy on the headstock end, and (3) explore modeling it using both PLA as well as wood, in order to understand to what extent the material affets the sound. 20

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