Playable 3D Printed Soprano Ukulele

Inspired by: Solstie - their instructable provides stl files of a 4 piece version like mine and a 2 piece version ready to print for people with bigger printers.

For my first time 3D printing, I wanted to make something that I could actually use and play around with, not like some trophy that just sits in my room all day. That's when I came with an idea to create an instrument I've always wanted to play, a ukulele. So, for my SIDE project I challenged myself to learn 3D printing and use that knowledge to create a playable ukulele. All of the resources, supplies, and guidance were provided by Ms. Berbawy's Principles of Engineering class. In addition, all of the paintwork was done by my mom. Thank you Ms. Berbawy, Solstie, and mom for making this project possible.

This project requires basic dimensioning and CAD knowledge.

MANDATORY

• 3D Printer Access - at least 7 inches by 3 inches and 6 inch height.
• CAD Software - ex: Fusion 360
• Slicing Software - ex: Prusa Slicer
• ABS/PLA Filament - at least 1kg
• Super Glue - parts are printed separately
• Screwdriver - depending on the tuners used you may need a wrench
• At Least 4 Tuning Pegs - Example
• Soprano Ukulele Strings - Example

OPTIONAL

• File/Sand paper - used to smooth out print
• Pliers - makes assembly easier if needed
• Razor - used to cut out supports
• Tape - Used to keep parts together when gluing
• Paint - color :)

Skip to Step 3 if you already have files. You can have dimensions by using an actual ukulele or buying a plan, but I used Solstie's 3D models for my dimensions.

The very first thing you need to have when starting from scratch is dimensions. When viewing an stl file, you can use the measuring tool to measure the 3d model. Make sure to write your measurements down somewhere to keep track. Cut the dimensions into four parts, top/bottom neck and top/bottom body (cut below the sound hole for the body). I recommend also measuring your pegs and screws to make holes more accurate, you need the holes to be just slightly bigger (I used around 5mm) or else fitting the pegs/screws would be difficult. You can also sketch some designs to add on your ukulele during this step. A soprano ukulele is 58 cm tall with 12-15 frets. My project is 48.5 cm tall with 12 frets so it's on the smaller side.

Skip to Step 3 if you already have files

The units in the picture is in mm, but the actual print has to be 0.1x smaller. I had to scale down each model to 10% after I realized this. The actual measurements would move the decimal 1 to the left in mm (ex: 1256.00 mm -> 125.60 mm)

You can now use your dimensions to CAD your own soprano ukulele. I used Fusion 260. I recommend you to CAD the pegs to help adjust the holes in the neck, as well as the screws to make screwing easier. Screwing through the ukulele without holes can be done (as seen in Soltie's version) but it's difficult and has the potential to break your print if you aren't careful (see Step 6). You can utilize the mirror tool to make things easier. You can add your designs on the 3D model during this step, just don't mess with the frets, holes, and bridge of the ukulele.

For the neck parts I started with the side profiles because it was easier to extrude them wide than thick. After extruding I used sketch and extrude to add the headstock. I used the extrude cut tool for the holes, nut, and fret markers.

For the body parts I divided them in half and used the mirror tool to mirror the sketch. After that I added the bridge with extrude and made holes using extrude cut.

After making this project, one problem I had was the headstock blocking my hand from pressing frets closer to the nut. I recommend leaving some more space on the part here the headstock connects to the neck to fix this problem (as seen on 6th pic).

Below are the files I made using CAD, feel free to change and customize them however you want (I recommend fixing the headstock for better playability).

Slice the model using a slicer. I used Prusa Slicer to slice mine. You can add supports to help with print quality but it's not really needed. I suggest not adding supports around the bridge as well as indents and holes because it may be hard to remove the supports in those areas. You can fit two bodies at the same time (as seen on the pictures above). Use 50% infill to shorten the time and resources used while still having a durable ukulele. You generally want to position the bodies to have the least amount of support possible. For my model, I positioned the necks facing sideways and the top base upside down.

Print Settings: 0.25mm DRAFT

Detect bridging perimeters enabled

Fill density: 50%

Generate support material enabled

Filament: Generic PLA

Nozzle temp - First layer: 230C; Other layers: 230C (necessary for the filament I used)

Printer: Orginal Prusa MINI & MINI+

I used the same settings for both neck and body parts

I also put support blocks on the sound hole, bridge, the holes on the headstock and the frets (seen on pictures above)

You can now slice and export the file to your printer.

After the print you will have some supports and some rough edges. Clean up your print using the tools you have. Some important parts to clean are the holes on the bridge and the nut on the neck, especially if you used supports on those parts (shown in pic 1, I had trouble cleaning out the holes on the test print since the supports were in a weird spot). After you're done, you can glue the parts together using super glue. You can keep the parts together to dry using tape to make it easier. It's very important to glue the parts properly and store it in a safe place when drying because it can affect its playability. The best way is to lay it upright to dry so that the neck can stay upright. Make sure it's fully dry before doing anything else.

You can paint before gluing the ukulele together, but I don't recommend it. Gluing first will make both painting and gluing easier.

You have the freedom to paint the ukulele however you want, just be careful about the frets and holes, they're needed for playability. I suggest getting help from someone who knows how to paint (example: mom). The way we painted it is by masking off the parts where we didn't want paint with tape and paper. Then we spray painted the parts that weren't masked. For small indents like the sun and stars in my design, we used a small paint brush. You can see in the picture that we painted first before assembling but we later found out that we needed the lines to line up in the middle so we painted over it again after gluing the parts together.

Please paint before adding pegs & strings and make sure it's dry to make painting easier. If you plan on painting after you already added pegs and strings, disassemble them first.

Now add the pegs using the the screws. Screw the pegs all the way in to make the pegs secure. After that you can now add strings. Make sure the strings are in the correct order from left to right, G C E A, for right handed players (G to the ceiling, A to the floor). There are many ways to tie the strings but the method I used is called the tie-block bridge.

Tie-Block Bridge Method:

1. Pull the string through the hole
2. From the bottom, pull the string under and over the top string to make a loop
3. Continue to loop the string (should look like 1st pic)

Be careful when screwing without holes, I managed to crack my test print because I was brute forcing a screw into the headstock (see 3rd pic). Work smart not hard, make pilot holes in your headstock for screws before screwing.

You can now tune the ukulele and play! If you don't have a tuner, you can download Ukulele By Yousician on your phone and use their built in tuner for free. You can learn songs on ukutabs.com.