Making a Plywood Upright Bass

Hi everyone! For this instructable I want to show you guys how to make a plywood upright bass. This was my biggest project for my senior year in high school and was the project that I took to compete in the 2012-2013 SkillsUSA district and state conferences. The main objective was to make a functional upright bass out of any material I could find locally which where I'm from, is not a lot. In all honesty, I did not think that my bass would work but I can proudly say that it sounds perfect to me, it may not be as good as those really expensive models but it can definitely hold its own ground.

Step 1: Tools and Materials

Tools I Used:
- Jigsaw
- Mitre saw
- Band saw
- Belt and disk sander
- C clamps( I used about ten 2 inch clamps and two 4 inch clamps but the more the better)
- F clamps( I used a good 8 of them)
- Drill Press
- Drill bit set
- Table saw
- Dremel
- Heat gun

Materials I used:
- One 1/4 sheet of plywood(for the top and back), can be any kind you want. I believe I used maple.
- One 1/8 sheet of plywood(for the ribs), I used lauan plywood though I highly recommend you use really bendable plywood like bendyply. I tried looking everywhere in town but I couldn't find anything so I had to go with the lauan plywood.
- One 3/4 sheet of plywood(for the mould), you can use any kind you want, it doesn't really matter it could even be MDF.
- One 2 x 2 x 8(for the corner blocks)
- One 2 x 10 x 10(for the neck, can also be used for the tailpiece)
- One 2 x 6 x 10(for the neck block, end pin block, can also be used for the bass bar)
- One 1-1/4 x 4 x 33(for the fingerboard). To get this, I cut a stock of oak that my teacher gave me, unfortunately it was short by about 2 inches so I added on to it, I will make it clearer on the fingerboard step.
- One 3/4 hardwood dowel(for the soundpost, can also be used for the end pin)
- Very thick string(to connect the tailpiece to the end pin)
- A strong wood glue(when making string instruments like the violin, cello, upright bass, etc. it is essential to use hide glue to make them but I chose not to and I will explain later on in the steps)
- One 1 x 10 x 1'(for the bridge)
- Tuning gears
- Upright bass strings

Step 2: The Mould

In order to make the bass' body a mould has to be used to give it it's shape. There are three shapes that I know of. The Gamba, Violin, and the Busetto. They are all very interesting and nothing short of beautiful and as my photo shows, I decided to make the violin style bass. In order to make the mould however, I had to draw it out on the 3/4 sheet of plywood using a grid. I had to be very careful with the placement of the corner blocks, neck block, and end pin block. Once it was drawn out, I proceeded to cut it out with the jigsaw. After it was cut out, I traced it over the sheet of plywood and cut it out again. These two mould layers were then separated in the middle with scrap wood. Finally, when the mould was cut out, I drilled a series of holes along the sides of the mould in order for the clamps to have something to grab on to.

In order to make the neck block, I assembled one out of 6 pieces that I cut out of the 2 x 10 x 12 and glued together(the last piece to be glued was thinned down by about 1/4 of an inch). I used the mitre saw to perform a dado cut on each neck block piece, I found it to be much more precise than cutting out the slot on top with a jigsaw. As for the corner blocks, I cut out four pieces measuring 8-3/4" long out of the 2 x 2 x 8. The end pin block was simply a piece of 2 x 6 that was cut to 8-3/4" in length.

Step 3: The Ribs

This was by far the hardest part of making the bass. Lauan plywood, like most plywoods, is made up of veneers with grains running perpendicular to each other making them very difficult to bend. For this reason I HIGHLY recommend the use of bendable plywood which has veneers with parallel grains making them incredibly easy to bend, had one of the stores in my town sold these, I would have bought it in a heartbeat.

I first cut out some strips with the width of 8-3/4" out of the sheet of plywood, these were the ribs. To get the length of each individual rib, I ran a string along the edge of the mould. Since the corner blocks all had 90 degree corners, each rib was cut with a 45 degree angle where they were to be glued together in order to have a clean joint. I then started the tedious process of bending the ribs. The trick to this was to wet the strip of plywood with a spray bottle and heat it with a heat gun all while applying pressure with the clamps. Small strips of wood were used along with the clamps to evenly bend the ribs while also preventing them from leaving indents on the ribs. When the ribs finally dried I unclamped them only to find that the ribs did not retain their shape all that well, so to fix this I traced the sides of the mould on what was left of the 3/4 plywood to make the linings. The plan was to make the linings of the ribs thick enough to force the ribs back into shape once they were glued on. I was a bit unsure if it would work but it did and they retained their shape without a problem.

Step 4: The Body

Once all of the ribs were glued to the linings, it was safe to glue them all together. The next thing to do was to make the top and back of the bass. I traced the ribs on the sheet of 1/4 plywood with an added 1/8 of an inch to the outline(this was done twice for the top and back). After I cut them out with the jigsaw, I glued the back to the ribs and added two strips of wood on the inside of the back plate for support. One strip was glued on the bottom and the other was glued directly where the soundpost was to be put, I don't know if it really helps but I always see flat upright basses on the internet with them so why not. After finishing the back plate, I drew an f-hole on to a strip of plywood, cut it out, and traced it on to the front plate.
Once I was finished with the f-holes, I proceeded to the soundpost. Normally, the sound post is added at the very end and installed with a tool specifically for that but I did not have the tool or the time so I decided to install it prior to installing the front plate. The trick to this was to place the soundpost on top of the strip of wood that was glued on the back plate, measure how much the soundpost needed to reach the front plate, and then add about 1/16 of an inch to have a secure fit. I put a drop of wood glue at the bottom of the soundpost so that it wouldn't move or fall.
Finally, I cut out a the bass bar from what was left of the 2 x 6, sanded it with the belt sander and glued it on to the front plate. I then glued the front plate on to the body.
Once the body was finished, I proceeded to stain it with a red mahogany wood stain.

Step 5: The Neck, Scroll, and Fingerboard

For the neck, I had to cut out two identical halves out of the 2 x 10 x 10. I then drilled 4 holes using the drill press and a 9/16 drill bit as 9/16 was the diameter of the tuning gear's peg. Once the holes were drilled, I proceeded to glueing the two halves together. When the glue was done drying, I had to cut out some of the neck as it is supposed to become gradually thinner as it reaches the pegbox, to do this I simply passed it through the band saw. Unfortunately, I couldn't get a photo of how the neck came out after being thinned down so I made a little diagram. I'm sorry if its not the most detailed demo but Its all I could think to come up with.
After I finished working on the neck, I began to work on the scroll and pegbox. Sadly, I didn't have enough time to carve out the pegbox and scroll with a chisel as competition was in two days so I used a dremel with a sanding bit. It didn't come out great but for the time being, it was more than good enough.
As for the fingerboard. I took the 1-1/4 x 4 piece of oak that my teacher had given me and began to plane it until it fit perfectly on to the neck. The only problem that came up when working on the fingerboard was the fact that it was short by 2 inches not counting the nut. To fix this, I decided to make a ut with a two inch extension at the bottom of it. To make the nut, I cut out a small rectangular out of the oak that remained and sanded it down with the disk and belt sander until it fit perfectly into the neck and fingerboard.

Step 6: The Bridge

This was the easiest part of making the bass. All I had to do was take a piece of 1 x 10 piece of cedar, draw a bridge, and then cut it out. I had to keep in mind how long the bridge was supposed to be as making it too short or too tall could drastically change the height of the strings from the fingerboard. When the bridge was cut out, I had to sand it down on one side while leaving the other side with a 90 degree angle. I provided a little demo of how to sand it down.

Step 7: The Tailpiece and Endpin

To make the tail piece, I had to draw it out on what was left of the 2 x 10 and then I had to cut it out with the jigsaw. When the shape was cut out, I drilled 4 holes, with a 5/16 drill bit then I cut a slot that ran up about 2/8" from the hole for the strings. The next step was to sand the back of the tailpiece where the holes are located using the belt part of the disk and belt sander. I then sanded off the lower back tip of the tailpiece. To finish off the tailpiece, I needed to make the tailgut mounting holes which is where the thick string is going to go through to attach it to the end pin. Using the dremel, I made an indent in the lower back of the tailpiece about 3/4 of an inch above where . I then drilled two parallel holes vertically up the tailpiece until the drill bit reached the indent I made.
The final part of the upright bass was the end pin. I drilled a hole 3/4" deep and 3/4" wide for the end pin. The end pin itself was a 3/4 dowel I had cut to about 8" which I simply glued in. I managed to tie the tailpiece to the end pin. I then I looped the remainder of the string around the end pin.

Also, all the photos in this step were taken after I finished the bass, I kind of had to hurry because competition was going to be held in two days.

Step 8: Finishing and Putting All the Parts Together

The night before competition day, my teacher and I added a finish of quick dry lacquer. We left it to dry thoroughly overnight and in the morning I arrived in the shop to finally attach the neck, tuners and strings. Instead of attaching the neck to the neck block with glue, I used 4 screws due to the fact that the glue was not going to dry in time. After competition I went back and added glue but I still kept the screws because I liked the way it looked.
Overall It came out to be a successful project and I was extremely happy with it. I owe a huge thanks to my carpentry teacher Mr. R. Miranda because I know that if it weren't for him, I would never have been able to make a project like this and I would never have been able to take part in SKillsUSA . Now that I graduated I'm going to miss the class but I managed to make a lot of memories there and a lot of projects too, so thank you sir for all the help and support you gave me throughout the years, I cant thank you enough!

Thank you for taking a look at my instructable I hope you enjoyed it :)

Comments

[BillD8]

lovely.
~i wish i could see the drawings though!

is it able to tolerate metal strings?
can it handle being slapped"?
if so, is the neck re-enforced? (it wasn't clear in the list there)

[Bassface72]

How did you determine the angle on the bottom of the neck?

[ConstructionDIYDan]

Anyone in SA looking for cheap ply, I used http://www.supply5.co.za/

[jorswag3]

Did you use a printed template to make the neck? If so could you upload it? Also, is it a 3/4 or 4/4 bass?

[jorswag3]

Did you use a printed template to make the neck? If so, could you upload it? Also, is this a 3/4 or 4/4 bass?

[Borrutje]

Hi buildingupbob,

Many thanks for sharing this project, and congratulations with the successful completion!

You may get quite a few followers, and therefore some comments.

1. Tuners.

I believe you have installed these tuners oriented the correct way. In situations where the peg is supported on both sides (like Double Bass = DB, Spanish guitar), the force of the string in combination with wear will cause the sprocket to go towards the tension, over time, so into the worm. In situations where the peg is supported on only one side (like electric guitar, bass guitar), the tension will cantilever the peg and wear will cause the sprocket to go away from the tension. In those cases the worm should be above the sprocket. Tuners made for mounting that way also have the gears cut in the other direction: a counter clockwise rotation of the flapper (as seen from the flapper side) normally causes the string to tighten.

I do however not recommend to drill the holes for the pegs perpendicular to the central axis of the neck, as you did with a column drill. In order for the tuners to fit properly on all sides, and without gaps, those holes should be drilled purely perpendicular to the outside of the pegbox they are mounted on. So if the 2 sides are not parallel, like here, the pegs cannot be parallel either. This is particularly important with pegs supported on both sides, and even more so with conventional DB plate-type tuners.

2. Instrument tension & bracing

One of the aspects in which your DB differs from a conventional DB, is that it has a flat top. The top is normally curved outwards, and one of the reasons for that is that the curved geometry, in combination with the longitudinal forces on it by the neck and the end nut, provides an upwards force in the centre. That upwards force helps to carry the bridge, at least on the E-side (with the G-side being largely carried by the sound post). The bridge pushes down onto the top with 2T.sin(90°-ß/2) (T = total tension of the strings, ß = the break-over angle, i.e. the angle the strings make when bending over the bridge), and that can be quite a significant force. Furthermore, with the bass bar below the top, the geometrical force is also downwards. So even though the strings you used are ultra low tension, I fear the top might be subsiding over time.

In a situation with a flat top like this, it should be considered to install the bass bar on the outside, i.e. between the bridge & top. It looks a bit silly, but that way you at least get some geometrical lifting capacity. Not quite enough, but it helps.

For completeness, the bracing on the back should stay on the inside, as you did. Conventional flatbacks have their bracing running sideways, but with a ply back longitudinal (as you did) is probably preferred.

3. Glue

My 2 cents as follows:

A perfect joint done with hide glue is amongst the strongest available, does not creep, lasts forever, is invisible, and hide glue has the advantage that the joint can be un-done by heating. But hide glue requires skill, diligence & patience, and without that very few joints are perfect. If it doesn't fit right, the water in the glue dissipates and you get air pockets (so 0 adhesion there), and if you didn't get the temperature right, the adhesion is poor (is why blades separate from ribs so frequently). Nevertheless, if you make a high value instrument, expect it to live for centuries, and it needs to be maintained: for such there is no alternative to hide glue.

But if you are not dealing with a high-value instrument, or if the joint you make is not supposed to ever be taken apart, or if your fit is not so perfect, or if you're in a hurry, you're probably better off with a modern glue:

- a foaming PU glue: can be reasonably quick & fill gaps. If a gap is filled with foam, it is not very strong - but probably strongest available for that poor fit. With a good fit, PU is sufficiently strong for most instrument applications, and lasts a long time too (certainly decades). Requires brute force to be taken apart, but can be repaired with new PU.

- epoxy: quick epoxies are generally lousy glues, weaker than marginally foamed PU. But they fill the gap, and you're done in 15 minutes. Again, some force to undo, and temperature helps too. Repair w/ epoxy.

Ultra slow epoxies can compete with hide glue for strength, but also require a good fit (though not necessarily as good as for hide glue), and final setting times in the order of months. Expensive too. Can be considered for a structural joint (or repair) never to be taken apart. In instruments, that's structural repairs only.

- PVA (white glue, carpenters glue): can be quick, can be strong, have some gap-filling capacity. But they creep, are highly visible, and are a dead-end street. Repairs are difficult to do well: nothing sticks well to set PVA, and it is difficult to remove. But it is easiest to work with, hence probably the best choice for projects like this.

4. Sound post (SP)

The exact placement of the SP makes quite a difference to the sound & character of the instrument. It is normally placed a bit south of the G-foot, and the optimal place is found by trial & error. If you don't have a setting tool, you can easily make something by bending thick wire in shape. After setting it at the approximate location, tap the SP to the desired place by means of some suitable tools (like an old-style soldering iron (= not electric, but the ones you heat-up with a flame), suitably bent). Of course set without string tension, and move after taking sufficient tension off the strings. Best not glue the SP in place.

In spite of all my comments: congrats with a job well done & many thanks for sharing it!

[buildingupbob]

Hello, sorry for a really late reply and thank you to you too for the all of the wonderful information. I can tell you know your way around a double bass. If I ever do make another one (which I hope I do) I'll be sure to keep all of this in mind as you've given me and everyone wanting to make one a lot to think about :)

[Borrutje]

If the string length (the sounding part = scale) is anywhere near 42", it is a 3/4 bass.

On the exterior bracing of the flat top, it's not something I thought of, I saw it from a guy who experimented w/ balsa violins. Physically (wrt carrying capacity of the bass bar) it makes perfect sense, and practically it allows you to 'tune' your instrument. When installing, you make the bracing a bit heavier than you think is required. And when all is assembled, you can thin it down to your liking, while being able to play the instrument & perceive the effect. Downside is that it doesn't look so hot. Bit industrial. (As bracing I would suggest a longitudinal bass bar below the E-leg, and 2 transversal braces at the widest part parts.)

More importantly: do you still play the instrument?

[purple_creme]

Sorry, but what size is it? I've been looking up basses and found that some are 4/4, 3/4, 1/2, and so on.

[buildingupbob]

Hello, I am incredibly sorry for being so late to reply but to answer your question I don't really know. It was supposed to be 3/4 at first but I ended up making it a good bit wider.

[MattisB]

Hi

i would like to thank you for your instructable. it was kind of giving me the last impulse to start an upright bass project by myself.

During my research the most i could find were comments like: just by a cheap one.

when i did finally find your instructable i thought okay just go for it.

I did several things different, but i am finally done.

so thanks

[buildingupbob]

Hello, sorry for replying so late but you're very welcome I'm very glad I could help :) and I love the way your bass turned out, it's beautiful in every sense of the word. You are incredibly talented!

[steve howe]

Great post and a good looking instrument. Please check out this link for discount bass parts http://www.janika.co.uk/Contrabass_Parts.php

[bippityboppityboo]

Hi, I'm just wondering why you didn't use hide glue? I'm looking at fixing a busted (REALLY busted) bass and considering hide glue vs. other types of glue for the repair, what do you think?

[buildingupbob]

Hello, I didn't use hide glue because I couldn't find any locally where I live and I was afraid it wouldn't hold as I had never used it before. The major setback with me not using it is that the glue I used doesn't dissolve with water so if it breaks, I can't really do much :/ but then again I made the bass for fun and didn't really keep this in mind.

[bippityboppityboo]

Thank you :) I'm suspicious of the odds because I fixed a smaller instrument (The neck of a guitar) with gorilla glue and it has held up in abhorrent climate extremes for almost a decade. That said a bass is a high tension instrument and probably actually needs the hide glue for a repair (instead of ground up construction)

[OrienteeringGuy]

Yes! We want a video.

[buildingupbob]

lol just uploaded one , I hope you like it.

[OrienteeringGuy]

Thanks! Sounds great. Rich deep sound. It would be interesting to have a practiced bass player put it though its paces. With your construction gift, you should invent some new instruments!

[Kiteman]

That *looks* really cool, but can we hear it?