Traditional instruments made with technology
So, Eddy, this is an English Concertina? Is that correct?
Yes, that's right. It features 37 buttons and has the note range from G3-D6. I created it using a computer and a 3D printer.
But on this model, the bellows are leather, which have been produced by master-craftsman Mark Lloyd-Adey.
Though you may be interested to know that Mark use my 3D-printed bellows jigs to produce his bellows.
So tell me about this thumb mechanism, Eddy.
The thumb holder is normally just a leather loop that holds the thumb perpendicular to the concertina face.
But I have noticed that the thumb naturally wants to be at a slightly different angle to perpendicular.
So I invented a large ball-joint with a thumb-sized hole through the middle, which can be rotated to almost any angle (which then may be locked afterwards using screws underneath.)
Nice. But the ring is plastic, which is quite firm. And people are used to leather, which is soft.
True. But the main reason soft leather is necessary is to accommodate the thumb which is not being held at it's natural angle. So if the thumb holder is a better fit, it doesn't need to be quite so loose or soft.
Plus having a more solid, well-fitting point of contact with the instrument allows a far greater degree of control (a bit like having tight-fitting ski boots).
It takes a couple of days to get used to, but it makes playing the instrument so much less tiring.
I see. But people have different sized thumbs, surely? Is there some way to adjust the size?
I have a bag of 50 different sizes of thumb rings already printed out to choose from. So I'm sure we can find one to fit almost any sized hand.
So tell me about the button mechanism
If you look at most concertinas, there will be some levers that are bent laterally in order to avoid other posts and levers. But this will inevitably cause some 'twist' in the mechanism, which is the most common cause of concertina malfunction.
But if you look at my mechanism, every single lever is completely straight, and every spring is central to the lever.
So there is no twist?
Correct. Also, there is a microscopic ball-joint at the end of each lever, which allows each pad to find it's own horizontal level, which means that if any small errors creep in during construction, there won't be any air leakage from the seal.
Regarding the levers, how does plastic compare to more traditional materials in the long run, say metal?
If you look closely, you will notice that each lever is printed as a truss, so actually, it's stronger than metal of the same thickness.
Neat. So how does the concertina feel to play?
Lovely; the springs are firmer than most, but the feel of the action is smooth and solid. Though the felt around and underneath the buttons makes it feel very professional indeed.
So tell me about the reeds you have used. They aren't standard concertina reeds, are they?
No, for this model, I have used decent quality, 'off-the-shelf' accordion reeds.
So how does it sound?
Great, actually: which I think due to a setting on the printer called 'infill'. Because if you set this value to around 15%, the printer then creates a rigid, hollow box - which is exactly what is required if you want something to resonate!
So with this setting activated, it turns our that 3D-printed plastic behaves very similarly to wood.
Tell me about the plastic you are using.
Currently, I'm using PLA, which is a derivative of maize (not oil), so for that reason, it is often referred to it as an 'eco-plastic'.
So what is this?
My father suffers from Carpal Tunnel syndrome: this is where the tendons for the fingers rub inside the wrist and then become inflamed. It happens because he is playing mostly with bent wrists.
So what I have done is create an optional 'bolt-on' part which moves the 3rd point of contact with the concertina away from the face, so that the wrist are now much straighter whilst playing.
NB. Also in this image, it is quite possible to see the angle that the thumb really wants to be (And it's certainly not perpendicular to the concertina face!)