EWC phonograph: problem when winding
Posted: Mon Mar 16, 2020 11:12 am
Herewith are some pictures of a small EWC (Excelsiorwerke Cöln) phonograph, modelled on the Columbia Q in its later form, which I have recently bought. I do not usually accumulate machines, but the price was moderate and I was charmed by the red and gold decoration which is still bright and almost complete.
I believe this machine is not far from being fit for use. It should have a wooden base or perhaps a box with a rotating lid, but this does not affect it mechanically. The reproducer from my Q seems to be compatible, as does the winding-key. (I already have an EWC recorder.) The reproducer carriage is of pot-metal and has swollen and distorted in the usual way, but it still slides freely on the guide-rod, and the cam which acts on the reproducer and the half-nut is functional despite having been broken and repaired. The mainspring is undamaged, the drive-belt (fabric rather than leather) is serviceable – thought I have enough material to replace it if necessary – and the motor components, including the governor, appear sound. However, a problem appears when I try to wind the machine: at first all appears normal, but after two or three half-turns the key tears itself out of my hand and whizzes backwards at a fearsome pace. My first idea was that the mainspring was broken near its outer end, so that it took the strain until its tension was strong enough to overcome the friction of the overlapping ends; however, as the pictures show, it is unbroken. I now believe the fault lies in the ratchet-and-pawl assembly; I say this because I once encountered identical symptoms in an old American shelf clock when the pawl itself fractured. Here the components – the ratchet incorporated with the spring cage and the pawl mounted on the inner wall of the motor housing – seem undamaged, and the pawl pivots freely on the shank of its retaining-screw. It strikes me as unusual, however, that the pawl is mounted upside-down, with its pointed ends upwards, whereas usually this part sits above the ratchet-wheel so that its own weight helps to keep one end securely between the teeth of the wheel; inverting this arrangement, as here, would seem to mean that the force of gravity becomes an enemy instead of a friend. Is it possible that there is a part missing, namely some kind of light spring which should bear on the tail of the pawl and hold it against the wheel? (Clock movements usually have such a spring, although I must admit that I have not seen the like in a phonograph or gramophone motor.) I can see no hole or stud which might have located such a spring, but it could have been simply wedged into a corner of the casing.
Is anyone familiar with these German machines? Should there be a spring as I have tried to describe, or am I missing some other cause of the problem?
Oliver Mundy.
I believe this machine is not far from being fit for use. It should have a wooden base or perhaps a box with a rotating lid, but this does not affect it mechanically. The reproducer from my Q seems to be compatible, as does the winding-key. (I already have an EWC recorder.) The reproducer carriage is of pot-metal and has swollen and distorted in the usual way, but it still slides freely on the guide-rod, and the cam which acts on the reproducer and the half-nut is functional despite having been broken and repaired. The mainspring is undamaged, the drive-belt (fabric rather than leather) is serviceable – thought I have enough material to replace it if necessary – and the motor components, including the governor, appear sound. However, a problem appears when I try to wind the machine: at first all appears normal, but after two or three half-turns the key tears itself out of my hand and whizzes backwards at a fearsome pace. My first idea was that the mainspring was broken near its outer end, so that it took the strain until its tension was strong enough to overcome the friction of the overlapping ends; however, as the pictures show, it is unbroken. I now believe the fault lies in the ratchet-and-pawl assembly; I say this because I once encountered identical symptoms in an old American shelf clock when the pawl itself fractured. Here the components – the ratchet incorporated with the spring cage and the pawl mounted on the inner wall of the motor housing – seem undamaged, and the pawl pivots freely on the shank of its retaining-screw. It strikes me as unusual, however, that the pawl is mounted upside-down, with its pointed ends upwards, whereas usually this part sits above the ratchet-wheel so that its own weight helps to keep one end securely between the teeth of the wheel; inverting this arrangement, as here, would seem to mean that the force of gravity becomes an enemy instead of a friend. Is it possible that there is a part missing, namely some kind of light spring which should bear on the tail of the pawl and hold it against the wheel? (Clock movements usually have such a spring, although I must admit that I have not seen the like in a phonograph or gramophone motor.) I can see no hole or stud which might have located such a spring, but it could have been simply wedged into a corner of the casing.
Is anyone familiar with these German machines? Should there be a spring as I have tried to describe, or am I missing some other cause of the problem?
Oliver Mundy.