It has been a while since I last posted here, thank you for your patience ;-). Meanwhile, I have been working on the new model, actually, I designed a few models that did not meet my expectations before I finally designed the ‘real’ new model. I am glad that after a lot of experimentation and dead ends, the current prototype has a great sound and is significantly lower in weight and smaller in size compared to the old model. There are however some radical changes and ‘kill your darlings’. The main changes are:
(btw, all images in the article open in a new tab after clicking)
body = resonator block
Note: the first image is of the prototype, ‘a sketchy draft’ with a cellotaped bodyrest and the old-style stand; still quite primitive. The second image is a first draft.
Big difference with the old model from a constructional point of view is, that the forces are no longer separated between a stiff carbon frame and a freely resonating ‘resonator block’ hanging in that frame. In the new model they are integrated again; the body = the resonator.
The new design is – I think – easier tot the eye, it looks more coherent, less ‘elaborate’ (it is however more difficult to make, the devil is in the details).
Still, the principle is the same as in the old model where the layers together built the desired tonal spectrum, but now, instead of only five layers, the body is so to say ‘a bundle of 23 tuned slats’, each slat with its own resonance frequencies. In essence, the body is a complex layered spring.
Also, the principle is still, that there is no ‘sound chamber’ or large resonating surface, because the body does not need to set air in motion and project sound to the audience (the sound volume level of the bass is comparable to that of an unamplified electric bass guitar).
In Essence, the Body is a Complex Layered Spring
No ball hinge stand
I left the idea of the ball hinge stand, because for some players who like high string action, the tilting ability turned out to be ‘rather a challenge’ when playing in thumb position on the fingerboard. Also, some bass players do not like to rest the bass’ neck on the shoulder, like others do when playing in thumb position.
The old bass model weighed 8,7kg, with a stand of about 5kg, total package with flightcase 21kg. Not exactly lightweight… So the demand I set, was that the bass should be easy to travel with, for example by train. To drastically reduce weight, I made the following changes:
I designed and developed custom lightweight tuners (machine heads), a complete brass set weighing only 640 grams, which is around one kg of weight reduction compared to a regular set of tuners. You get the same gear ratio and look of upright bass tuners, at the weight of bass guitar tuners:
practical size and weight for transport
The total length of the new bas is ±155cm, weighing around 4,5kg, a radical improvement compared to the bulky 170cm and 8,7kg of the old model. Including the flightcase, the total package of the old model was 21kg… Next to a flightcase, I am planning a softbag for the new bass + stand + bodyrest. When using a softbag, the total weight of softbag, bass + stand + endpin + bodyrest is estimated to be be around 8kg.
endpin and stand integrated
right picture: prototype study of V in carbon, the two halves can be seperated for easy transport.
Instead of running a seperate endpin through the bass, the pole of the stand becomes the endpin. The endpin will be made out of carbon, and will be integrated with the carbon V-stand. Putting the bass in the stand is done by placing the endpin in the V.
Abandoning the ball hinge in the stand was indeed a classic ‘kill your darlings’. Trade off is, that the bass is no longer meant to be played in the stand, but nevertheless I am happy with the new design. For playing ergonomics, the bass is now equiped with a (removable) bodyrest that is adjustable in height, size, distance-from-bass and angle (friction ball hinge).
Last few months I have been working on figuring out a way to make a telescopic carbon endpin (height adjustable) that is curved to a slight bend. During the design process – ‘drawing board’ – I thought the method I had in mind for making these bent tubes would work, but it didn’t… After quite a few frustrating attempts and different moulding techniques, I finally found a method to control inner and outer diameter of a curved carbon tube and make the curves fit exactly to make the telescope work. Especially releasing the inner mold out of the carbon tube requires some magic tricks.
Another problem in the endpin design I had not anticipated during the design process, was that without the ball hinge, the connection between endpin and bass body should be rigid, really rigid. Since the body is partly made out of softwood ( fichte), I could not get the connection rigid enough; make one part rigid and the problem shifts… In practice this meant that when playing in thumb position, the bass would bend a little bit with the force applied. You don’t want that, this ‘wobbling’ gets really annoying. Also, this deformation will over the years wear out the endpin – to – bass connection further and the tilting wobble will get even worse. So finally I conceded in making a subtle rest for the body halfway the endpin, a ’tilt-stop’ so to say. And now it is rigid.
Currently I am working on a better way to build the body; I like to have a better method of quality control over the tone during the process of building, especially the tonal area from low E to A. This may take a few weeks or a few months, I don’t know yet (I’m still learning every day). Next to this, I am planning on moving to another workplace, and then the production has to be set up, a new website, a softbag and flightcase need to be designed etc… So, there’s a lot of development going on here, we’re talking months. I’ll keep you posted!
(last updated aug 23, 2017)