December 1, 2016 at 8:53 pm #7886
A spring of some kind or other is an essential part of every melodica key, so far as I know. One common kind of spring is the kind displayed in the following photos. I think this is called an extension spring — someone please correct me if I’m wrong or let me know if there’s another name for this kind of spring. Not all of these springs are created equal. They differ from one brand or model to another, but they also sometimes differ within a particular set of springs. A difference in “springiness” from one key to another is often noticeable on vintage models, as is the case with the Silvertone Orgamonica whose springs are shown here. This could be from a spring’s having been stretched, in which case it would be less springy and the key would be easier to depress. And if you have a key that is springier than its mates, you can weaken its springiness by taking it off and stretching it a bit. Springs might differ if one has been replaced. On this Orgamonica, however, notice the difference between the third spring from the right and the second and fourth springs. On this instrument, the black keys have weaker springs than the white keys by design.
One of the problems I’ve encountered with this instrument was that the top black key (Ab) was sounding all the time, sort of half-sounding. This is not an uncommon problem with old Italian melodicas. I tried fiddling with the key mechanism, bending the arm so as to have the key pad better centered and not interfered with by the adjacent pads. Finally I tried exchanging its spring with the spring of the very bottom key, a white key (C). This solved the problem. In the next photo, you see the replaced spring on the Ab, and in the next the replaced spring of the C. That C is much lighter to the touch, but it sounds only when depressed. My guess is that it is nevertheless allowing air to escape. There are other keys on this keyboard that are also relatively light to the touch, less springy. So I’m thinking that one cause of leakiness on some vintage melodicas might be that some of their keys’ springs are weakened, resulting in less than full contact of the key’s pad with the air hole. While we’re thinking that maybe pads need replacing, it may actually be a spring problem.
Small springs are readily available at Amazon and at other Internet outlets, but it’s hard to know which ones would be good replacements for a melodica. I probably can find some that will work for the Orgamonica on one of my “parts” melodicas.December 2, 2016 at 6:28 pm #7890
How to add tension to one of these springs? Clip off one or two coils.
It is a great advantage, of course, to have adjustable spring tension, as is the case with The Clavietta and some early Pianicas, which have compression springs. It would seem that ideally we want the same degree of key tension up and down the entire keyboard. Greater tension is an advantage in relation to control of the individual key, for example for bending notes, but there will be corresponding disadvantages. Just now checking several different brand and model melodicas, I find that with several, tension seems to increase as we move up the keyboard, so that the highest key has noticeable more tension than the lowest key. Possibly it’s because the lower end has been played more than the higher end.December 6, 2016 at 4:28 pm #7928
Lovely post on springs Alan. Black keys are harder to press down because they are shorter than the white keys. I found this on my 3D printed melodica, and adjusted them to be slightly looser to compensate. I notice there’s no need for this on my P37D. It takes equal pressure on both black and white keys, using the same spring. Maybe this is because the black keys are lighter?January 25, 2017 at 9:21 pm #8179
There seem to be three main kinds of springs used for key tension on melodicas: Extension Springs, Compression Springs, and
The extension spring is stretched. This kind of spring is usually fairly easy to remove and replace. Tension can be reduced by slightly stretching the spring and increased by clipping off a loop or two. An extension spring can usually be replaced by one of similar size and gauge, with some adjustment. The compression spring, as found on the Clavietta, is compressed with pressure on both ends. In a melodica, it is likely to be adjustable with screw or nut on one end. It is very easy to lose this kind of spring since when the pressure is released at one end, it will launch itself off into the distance. It is best to remove and replace these within an enclosure. The torsion spring is hardest to work with. It typically is compressed under the key, making it harder to remove and replace keys and to get the spring into place. Tension can be increased by pulling the ends of the spring apart or compressing them together. It seems to be harder to get this just right than with the other types.
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