Piotr Sell's Electric Upright Bass

[Piotr Sell]

Hello everyone,

After a long absence I would like to share a project that I completed last week. It is an Electric Upright Bass, it is my third instrument and it took me almost four years to design and build it. Compared to my previous projects it was a rather daring challenge considering I wanted to achieve a very sleek hi-tech results with some even more lo-fi building techniques.
Just like it usually happens with all from scratch projects there were some hard moments and from time to time pushing it forward felt like forever but in the end it really was a great adventure and looking back on all the time I had spent working on it the final outcome is more than rewarding.

The whole story started somewhere in 2008. I had just completed my first electric guitar that some of you might remember as ‘quite elaborated for a travel instrument’ guitar and took it with me when I first moved abroad. I soon noticed that my attempt to design a ‘new’ guitar didn't work out. Back then I saw the guitar as an object not an instrument, I guess. Though I consider my first guitar a sort of ‘failure’, working on it did gave me a lot - the essential skills and confidence in woodworking and an interest in complex shapes (not that I had a complete control over what I was doing).

My second instrument was an exercise of a different kind. I wanted to improve my overall control over details and so I decided to build a slightly modified copy of an electric guitar model produced by one of the big brands. The result is a guitar that at first appears just ‘black’ due to the fact that the personal feel is given by rather subtle details. A very particular comment I heard from one friend was ‘it looks like a real guitar compared to what you did before’. My conclusion was that if I ever want to make my original design feel ‘real’ it can’t be a guitar anymore.

In 2009 Simon, a fellow double bass player, got interested with the guitars I have built and so at some point we started discussing if it could be a good idea to try to build an Electric Upright Bass. I knew very little about double basses at that moment. Being aware of possible consequences of a careless design we have had spent a good half a year discussing the whole thing. And so it had been decided the new instrument should keep the key features of an acoustic double bass. To be sure that I really got it right I had built a quick & dirty but playable prototype before starting to work on the real thing.
I have to mention that NS Design basses were the very first of the kind that caught my attention and made me realize how interesting such a ‘stick’ can be. However I hate the idea of an instrument fixed on a stand their basses still were my main reference.

Photo: Kuba Styperek

My Electric Upright Bass is shaped to suit a double bass player not a bass guitar player. The ‘strip’, which is what I call the fancy black thing, serves primarily for the instrument to be rested on player’s hip. The concept of a ‘rib’ that is shaped like a contour of the double bass’ sound box is nothing new. I only dare to say that what I managed to achieve is a pretty good integration of the ‘stick’ and the ‘rib’. The result is a nicer feel of the instrument as a whole because it has no ‘framed void’ kind of effect to it. The twisted ‘strip’ is there to create a volume which gives this instrument a stronger spatial presence.

Specs:

- flame maple bolt on neck and body
- beveled ebony fingerboard
- ebony head cap, bridge and string ferrules
- acrylic finish (which I didn’t spray myself, special thanks go to an expert in the field RM)
- Realist piezo pickup
- custom made Zadow magnetic
- K&K Dual Channel Pro Preamp


At this point I'd like to thank the whole MIMForum for being a great source of information and inspiration!
A very special thanks go to Nick J. Dolby, the creator of the wonderful Burlapcaster. His detailed description of how a composite laminate can be made got me interested with the technology that allowed me to shape the ‘strip’.
Another forum member I would like to thank is Mauro Marchesini whose amazing Stylus electric upright bass and his travel guitars were an important reference and great inspiration for my project.

[Simon Magennis]

Gorgeous. Makes me want to learn the bass!

[Piotr Sell]

I forgot to officially thank the photographer Kuba Styperek (Strike-Photo) for shooting those great photos of the bass. Thanks Kuba! without you the world wouldn't get to see this instrument

[Hans Bezemer]

That's a very nice EUB you've build Piotr!
Do you have some close up pictures?

Hans

[Steve Senseney]

Very interesting and looks great!

I would like more details in the pictures and some further information about you design and how you made your choices.

The pictures are well done.

[Mauro Marchesini]

... Another forum member I would like to thank is Mauro Marchesini ...

I would like to thank Piotr for the credit he gave me, but I think his project perfectly expresses his great creativity and his outstanding craftmanship.

[Piotr Sell]

Thank You for all kind words and interest!

Here are a couple more close up pictures to explain some of the details:

Headstock
It looks like a standard EUB headstock and so it is, but figuring out things like strings' break angles wasn't that straightforward. A great reference to understand how it should be shaped to make it work was the 3D model of Mauro's 'Stylus' bass I spotted on his website (many thanks once again, Mauro).
I wanted this headstock to appear as an extension of the fingerboard, so I added an ebony cap I made from a piece I planned to use as guitar fingerboard one day. It was thick enough I could make it curved. A nice detail, I think, is the nut which is set in a little cavity.

Photo: Kuba Styperek (Strike-Photo)

Pickups and Bridge
Piezo is hidden in the bridge cavity and the bridge is a sort of plug. Behind the bridge you can see the ebony string ferrules "stolen" from Mauro's EUB. The magnetic pickup that has been custom made to fit the beveled fingerboard's profile then I added an epoxy+ebony dust cover partly reinforced with fiberglass. I wanted to make it a sort of invisible pickup that seems to be a piece of the fingerboard, so the mounting system is hidden underneath the fingerboard. It's a simple solution and includes just a small block of ebony and a pair of machine machine screws to hold it in place.

Knobs
They are pretty big and set almost smoothly with the surface. The idea I first saw on the 'Niwa' guitar by Ulrich Teuffel. Mine work much more like thumb-wheels though.

Photo: Kuba Styperek (Strike-Photo)

Photo: Kuba Styperek (Strike-Photo)

[Piotr Sell]

Before I get to explain how the 'Strip' works and how it was made, here you can see the prototype design that developed into the instrument you can see in the photos above. I also built this prototype which allowed to verify that my design really works. As you can assume I got confident enough to tweak it further. This initial experiment had also helped to spot several issues that had to be resolved in the final design. Like the generally too long, wobbly end-pin to name just one.

A rendering of the prototype design of the EUB

[Piotr Sell]

Have a look at this picture. It should make more evident that the 'strip' is integrated with a sort of skateboard-shaped back plate of the bass. This pack plate is bolted onto the bass and has the end-pin mounted inside. Originally, instead of bolts I planned on using some "quick release" kind of mounting system but abandoned this idea.
Unlikely the prototype design where the 'strip' was something to be attached to the instrument, here the "stick bass" is mounted on the "virtual sound box".

Here you can see the thing alone. This shot reveals the end-pin channel and screws that fix all three pieces together.

And here it is disassembled.

Structurally the 'strip' is an epoxy and fiberglass composite with a polyurethane foam core. The back plate has a composite skin wrapped wooden/plywood core and the last piece is basically a wooden block. I'll try looking up some photos to explain it further.

[Piotr Sell]

I'm back with few more photos dug from my archive and hopefully more story to tell. Like I mentioned at the beginning, this instrument has a clean look but it has been achieved the dirty way. Often limited to long hours of patient sanding. I did the whole thing "my" way rather than the "correct" or even "practical" way and I must say that a lesson learned is that although now I have no slightest doubt that just about anything is possible with even the simplest set of tools, sometimes it just takes too long and a struggle with some silly detail makes you loose the track of the real challenge.

First I'd like to explain how I progress with the design and built. As you must have noticed the preliminary design has been greatly modified before it reached the final form so it wasn't like I had a 1:1 reference. I had used 3D modelling software to support the design and to be able to print some templates but not everything could have been simulated.
When I defined the general characteristics and dimensions, I moved onto building to get more or less to that point and see if everything works as planned. Then I got back to defining the details.

In this picture you can see the first stage completed. It allow for first testing of the bass. What I needed to verify was in first place if my idea for the bridge placement works and if shortening the free length of the endpin to ~50 from ~65 cm is enough to overcome the wobbling of the bass. Back then I also considered some more inventive way of fixing the 'strip' on the bass. The block made of plywood in the background was an attempt to 'rail connect' the two parts which were supposed to slide one into another. What I haven't considered was how powerful are the string vibrations that resulted in rattling due. In the end I gave up on fancy tricks like that and bolted the whole thing together.

a photo from 2011 (note the less ordinary neck joint)

The second stage was focused on the shaping the model of the 'strip'. In this image you can see a block of had, flooring polystyrene (two sheets 10cm thick glued together). Aside from building industy, this material is also used to CNC route models for mold plugs of boats and such. I shaped it by hand then put a layer of acrylic putty which wrapped in PE foil served for initial lamination. It's the white block in the foreground. The black 'strip' in this shot is the prototype that I used as reference.

I took this pictures few days ago but these things were collecting dust since summer 2012

This is a picture of a mock-up fit, the bass is just lying on the other part. You should be able to see more or less how the strip's model has been made - the redish stuff is polyester resin while the creamy one is polyester putty. After molding roughly the outer surface of the polystyrene plug or whatever it should be called in this case I built the thickness of the profile piling up tons of putty.

this is an actual picture from 2012

In this picture we have side by side the model of the final 'stip' on the left and the prototype on the right. If you look carefully you'll see that the various twists and fold of the final shape are there not just for the looks. They actually strengthen the essential spots of the 'strip'.

once again a recent photo, the model which is covered in primer has been already used for molding

[Piotr Sell]

The before mentioned second stage ended with the basss looking like this:

the taped thing is the pickup that was still missing it's a fixture to mound it on the fingerboard end

Note that even though I spray painted the model of the 'strip' I wasn't even close of being ready for molding. You might also noice that its both ends weren't yet defined precisely. I left that for the final stage.

The third stage involved finishing the bass and shaping all ebony accesoriess, I mean bridge and knobs, but first and foremost making the real 'strip'.
In these two photos you can see the mold making process using polyester resin (later I switched to epoxy for its much lower shrinkage). This was the only mold I made, so as you see it was just the outer surface of the thing. The main reason was that I had yet to define the ends and the mounting system of the 'strip'.

it appears black because it's a black gel-coat that You can seethrough the laminate

even a partial shape made it difficult to pull the model out, I had to break it in two

Here's a picture of final molding in progress:

plenty of excess fiberglass

And here you can see the polyurethane core after initial cutting to shape (I used a bi-component spray can foam). A more classical core material would be something like a hone-comb but that has a set thickness. I decided to use foam like this because it allowed me to play freely with the thickness of the profile, to sort of sculpt it.
Later I layered the inner surface of the laminate (just like before I used a combination more or less like this 50g+150g+3x300g of fibrerglass) directly over the foam core. Then, when it cured, I went on sanding it for a long, long time.

there are some cavities yet to be filled

[Jason Rodgers]

This is some amazing design and execution, Piotr. The "strip" looks like a swirling silk scarf frozen in the air. I wouldn't know how to begin making such an object. Inspiring work!

[Piotr Sell]

Here you can see it together with the other pieces right before spraying first coat of primer. You might notice there are pieces of wood at both ends that allowed me to set the threaded inserts. Well, I know it doesn't appear overly impressive in this state. I have to say that even though one can shape a composite by sanding it is not the best idea to do it so. Anyway, the final super sleek look is much due to double coats of primer and even more sanding...

This final shot presents all of the pieces finished

a picture of all the parts togheter

[Piotr Sell]

An important image that was missing is one of the bass in action! Here you can see Simon jamming:

Simon playing the DSDV 3 bass

At some point I will also post here some sound samples or videos.

My 'dirty' workshop secrets are already revealed so If anyone would like to know anything more I'd be happy to answer any question.

[Rodger Bryan]

Piotr,
Thank you for sharing the design. The "strip" is something that I would expect to see at the Guggenheim- its a great, well thought-out design and the execution is beyond anything I could pull off.
I also like how you incorporated the endpin into the back plate. On my current design/project (which I hope to share this summer) a little bit of influence from NS and Clevinger models, but seeing your ideas make me want to spend more time working with pencil, paper and eraser first.

What is the string length?
What type of piezo material did you use? (ceramic, film, cable?)

[Steve Senseney]

Thanks for giving the rest of the story. It really looks great, and well thought out.

[Piotr Sell]

Thanks! I'm glad You like it.

I hope the process of development of the design I described here might be of some use for others working also on different projects. In my opinion it's much better to take your time and refine the design before you get to the actual building and sometimes the "test on scrap" rule could apply not only to finishes but to the general ideas as well - prototyping is time consuming but is also very helpful.

Rodger, this EUB is shaped after a "standard" 3/4 double bass taking certain measures, like the scale length, directly from Simon's acoustic. I looked it up in my sketchbook and it was 1050 mm. I advise you to get the strings already if you plan on using a similar string through body layout. You need to know the total string length to do it right.
I didn't do the piezo pickup myself, the one I is called Realist and I have no idea what kind of piezo material it is made of.

I'm happy you see this instrument "arty" but the only "exhibition" it should ever take part in is the one that usually happens on stage. Also, my design has much more to do with "Batman stuff" and alike than the fine arts...

[Gilbert Fredrickson]

Very exciting design. Great use of materials.