Acoustic Violin 4/4 - Stridivarius Fiddle

This full-size acoustic violin is an improved version of the model by MasterChief2552 that I remixed/modded according to the real violin specs from MakingTheViolin.com (original small-size model here).

Some parts are adjusted or remixed, while some are rebuilt from the scratch, in order to obtain required specifications and gain strength in critical places. It has additional holes and mounting pins for easier, more accurate assembly.

Performance compared to a “real” violin

Despite the pretentious name, it does not pretend to be a high-end violin, even though according to my musician friends' evaluation, it performs a lot better than cheap low-end commercial violins. 

Here's a sample of a friend of mine playing it and comparing the sound with a real violin: https://www.youtube.com/watch?v=PKABQLonJO4

To prevent the violin from breaking, you should release the strings when you don't intend to play it for a period longer than a few days.

UPDATE - 2022-08-23

• Enhanced tailpiece for better strength (part #12)
• Enhanced bridge to ensure proper wire heights (part #9, remixed https://www.thingiverse.com/thing:2322669)

Print Settings

Supports:

Yes

Resolution:

0.10

Filament: DevilDesign PLA 
Notes:

Default layer height: 0.10mm
Default perimeters: 2
Default infill: 20% gyroid

• Parts 1-4, 7, 9: default
• Parts 5-6: 0.15mm layer
• Part 8: 30% gyroid infill
• Part 15, 16: 50% gyroid infill, 4 perimeters, 16 top layers, 14 bottom layers
• Part 11: 30% gyroid infill
• Parts 12, 13, 14: 100% infill, 4 perimeters

Required Material and Tools

Filament

Use PLA, because must be rigid in order to resonate.

ABS or PET would absolutely be abad choice!

Tools and materials

• Water-resistant sandpaper (grit 150 to 400 for rougher parts. up to grit 1200 for polishing)
• Quick clamps - one, two or even more (I had two)
• A couple of files
• Superglue gel (not a regular liquid superglue)
• 3D pen or a welding iron

2mm x 20mm nail (for the tail-knob) Optional

Putty for plastic (I used Revell Plasto putty)

• Spray putty
• Plastic primer
• Spray varnish for plastic
• Displex mobile display polish, or any other polish for plastic

Cotton pads (for polishing) Real Violin Parts

Violin strings

• Tailgut
• Chin-rest
• Shoulder rest
• Fine tuners
• Bow

Post-Printing

Sanding

All the parts need to be sanded. You can use files for initial smoothing of the roughest parts. For sanding, start from grit 150, gradually going finer to 400 for regular parts. For the glossy parts continue with grit 800 to 1200.

NOTE: PLA is a very hard material, but it becomes mushy around 50°C. These two properties make PLA very difficult to sand and polish. Splash it with water to keep the material cool while sanding, and use water-resistant sandpaper.

The tailpiece is polished to the glossy finish using the sandpaper and some plastic polish.

Filling Gaps and Crevices

I used putty for plastic to fill the crevices, and spray putty to obtain glossy finish of the neck and the body of the violin.

Theoretically, you could sand it down and polish without using any putty or varnish (like I did with the tailpiece), but it requirestoo much effort.

NOTE: Use just a bare minimum amount of the putty and varnish. It increases mass of the instrument and additionally degrades the sound.

The body is finished using spray putty, plastic primer and glossy white spray.

Assembly

Assembled violin (without the pegs, the tailgut and the wires)

The Body

• The front, the back and the ribs are printed in two parts, so each pair first has to be assembledfirst by gluing andthen welding (see the sections below)
• The parts have to be assembled as shown on the picture above
• Some of the parts have 4 mm holes where you have to insert the pins, in order to assure a proper positioning. Before inserting the pins, use a 5-6 mm drill bit to slightly bevel the edges of hole Welding the front plate

Bass Bar

The bass bar has to be glued to the front plate on the position shown green on the schematic above.

• The flat side of the bar has to be glued to the front plate, so it pushes the plate as a spring
• It has to be equally distant from the bottom and from the neck of the violin.
• When looking from the back side of the front plate, it has to be shifted to the right, so it is 3 mm distant from the upper serif of the f-hole Apply some superglue gel to the flat side of the bass bar, press it strongly against the front side using a few clamps, and weld the sides of the joint along the bar.

The Neck

After gluing the bottom plate to the ribs, you can glue the neck to the ribs. NOT BEFORE!

Sand both contact surfaces, apply the superglue gel, place the part to the proper position and use the quick clamps to firmly press it for a minute or two.

If you did everything right, the neck will be now super-strongly attached to the body.

I made a mockup example to test the strength of the bond, and believe me, it is much stronger than you would ever need it to be!

Tail Knob

The tail knob (part 14) is printed from two parts, that have to withstand significant force.

1. Glue the two parts of the knob together.
2. Use the quick clamp for additional pressure for about a minute.
3. Drive a 2 mm x 20 mm nail through the middle.
4. Polish the knob to give it a glossy finish. 

NOTE: Do NOT glue the tail knob to the body of the violin! You will occasionally want to remove it to uncover a peep-hole that will be your best friend when it comes to adjusting the sound post! Also you might need to replace it with a new one if it breaks.

The Tailpiece

The tailpiece has to be very strong, so you should use the following settings:

• 0.10 mm resolution
• 4 perimeters
• 16 solid layers on top, 14 solid layers on bottom
• 100% infill 

When mounting the tailpiece be sure not to tighten the tailgut too tight, because it will ride the saddle, what will cause it to bend and eventually break. The tailpiece has to barely touch the saddle!

The tailpiece should be set slightly longer than shown on this picture, so it does not directly touch the saddle. There should be less than 1 mm distance, not more! Double-check it after having the strings tuned!

The Pegs

The four pegs also withstand significant forces:

• The force from the wire.

The torsion from winding the pegs. They have to be printed lying down (not upwards), or theywill break.

You have two options:

1. Print the pegs from a single part, using supports (this gives a bad finish from the bottom side, and you'll have some difficult times to make it look good).

Print each peg from two halves, using no support, and then glue them together. The second option gives the best result, but it requires some skill to perfectly align the two parts. You can use the "mbox" tool (or "mounting box", part 16c):

Place one half into the box;

1. Apply some glue along its middle;
2. Place the other half into the box lid. You can apply asuper-tiny amount of glue to the part that goes into the top lid, to prevent it from falling out.
3. Put the lid into the box, ensuring that the pegs stay in their positions.
4. Use a quick clamp for about a minute, to press the two parts together.
5. If the lid does not come out easily, you can use the "mbox-extractor" (part 16d) to extract the lid and the peg. Pegs must be polished and perfectly round!

Aligning the two peg halves: Blue is the peg alignment box and its lid, the red is the peg extractor.

Assembly Techniques

Gluing

I used Loctite and UHU superglue gel. I don't recommend using a regular liquid (non-gel) glue.

When pressing two parts together, you must apply a steady, strong force for a minute or two. I used this quick clamp with my modded rocker pad.

Welding

Some parts must be welded together. I used a cheap 3D pen for the purpose. The following parts arefirst glued andthen welded together:

• Two pieces of the front plate (1 and 2)
• Two pieces of the back plate (3 and 4)
• Two pieces of the ribs (5 and 6)
• Bottom plate to the ribs

Bass-bar to the front plate (7 to 1+2) IMPORTANT NOTE: While welding parts glued with superglue, strong poisonous vapors are produced! USE PROTECTIVE MASK FOR BREATHING AND EYES PROTECTION and work in a well ventilated area!

Finalizing

Placing the Soundpost

The soundpost acts as a fulcrum between the front and the back plate. Without it, the violin is not able to produce a strong sound.

Placing a soundpost is a tricky business that requires a lot of patience and skill (or time). The soundpost has to be placed vertically inside the violin (through the right f-hole), about a few millimeters below the right leg of the bridge.

There are many videos on YouTube showing you how to do it, and this is just one of them: https://www.youtube.com/watch?v=mU4xtg6wNLc

If you want to use the enlosed soundpost tool, you must first bend it in a Z-shape (or better said a double-sided "L" shape) using a blow-dryer.

Stringing a Violin

There are also many videos showing you how to string a violin. Here is a good one: https://www.youtube.com/watch?v=DqD0jI3tm-o

Tuning a Violin

Tuning a violin is very tricky, since changing a tension in one string also changes the tension of other strings. If you move the pitch of one string up, the others go down.

Therefore it is an iterative process. When you get practice, you will do it in 2 or 3 iterations.

Also, adding a fine tuner to the tailpiece makes tuning much easier, but adds mass to the tailpiece and degrades the sound. I have also seen guitar-style tuning mechanisms for a violin, that completely eliminate the need for fine-tuners and make tuning a violin a breeze.

I use the free GuitarTuna for tuning my string instruments:

• GuitarTuna on Apple Store

GuitarTuna on Google Store IMPORTANT: Be very careful while tightening the strings, because they may easily break and hurt you!

How it Sounds

Here is a friend of mine playing the same piece on this violin, and then on a "normal" violin.

Possible improvements

Thicknesses of the front and the back plate on this model are not properly modeled, so this violin, even quite loud, lacks in the timbre and resonance in high frequencies, giving it a muffled sound. You would not like to play Vivaldi or Paganini on it, but it is more than enough for fiddling some good old bluegrass or country.

In order to get the best of it, one should have to adjust thicknesses along certain zones, to obtain specific resonance models, as described here.

If you have the time and will to do it - be my guest!

References

1. Original model by MasterChief2552
2. Full Size Violin Bridge by Seabass_E (modified)
3. MakingTheViolin.com
4. Documentary The Great Violin Mystery

Category: Music