Yesterday, I wrote:
> [The repetition distance is] around 4.2 mm on well-kept 20ers ...
and Robbie concluded:
> [ Wolfgang Brommer told me the paper of 20er music rolls, pulled
> [ at constant speed by a capstan, typically moves at 60 to 70 mm
> [ per second. 70/4.2 = 16.7 notes per second. That's speedy!
But my remark was at least unclear (and, therefore, so are the
repetition distances in the small-organ scales on MMD): By my
definition, the "repetition distance" is from the _end_ of one hole
to the _beginning_ of the next. So, with a standard hole diameter
on 20ers of 3.0mm, you get about 70/(3.0+4.2) = 9.8 notes per second.
And Robbie is of course correct that this _distance_ is of no use
to the arranger if the _speed_ of the paper strip or carton is not
defined. Therefore, a _repetition time_ might be more practical.
However, for all organs I know, the speed is actually quite well
defined.
(The large range of 60 to 70 mm per second given for the 20er is more
an exception than the rule; also, as far as I know, not many people
punch 20er rolls with 70 mm per second -- but Jäger and Brommer do so).
Regards
Harald Müller
[ If 70 mm per second is the _exception_, then, pray tell, what is
[ the well-defined speed of the _rule?_ ;-) -- Robbie
|