No expert here (just amateur fiddler) but I have noticed that many bells seem to have their 'centre' fixing hole drilled eccentrically.  Thus by losening the securing screw and turning the bell slightly, it can be made to lie in a more satisfactory reltionship to the hammer / clanger.  I have found that the required adjustment is often very fine.

The other aspect of this is to ensure that the hammer mechanism is clean and can move freely.  Check also that the lug (attached to the right margin release unit) which operates the hammer as it moves past it is 'raising' the hammer sufficiently.

Anyone knowing better, please add / correct.

Last edited by beak (21-7-2014 08:49:27)

I managed to give a bell a more satisfying ting by loosening the central screw a bit. Just a tiny amount was all it took.
Sometimes the hammer can be resting on the side of the bell, which means it will only give a 'dunk' sound - if you bend the wire holding the hammer, so that the hammer is a couple of millimetres away from the side of the bell, it should give you a 'ting' instead. I find that fixing a bell is very satisfying!

 

As has already been suggested you can improve on weak bells, the method varies from machine to machine. Experimentation is the key, but most important, you have to first make sure that the hammer mechanism is working perfectly. Like every other part of the machine, the pivots and linkages of this mechanism can be adversely affected by dirt, grease, and corrosion.