External to the punch mechanism, everything seemed
OK... but deep
inside these pins were binding and nobody was gonna play that way.
The solenoids are very tiny and completely enclosed inside the punch
mechanism. The only thing external is a pulley around which goes
a round belt over to a DC motor which provides the power. There's a
bigger solenoid as you describe which advances the tape but that too is
totally enclosed within the punch assembly.
This sounds a bit like the GNT Model 34 mechanism, which I have the
service manual for. In this punch, the punch pins are controlled by
solenoids in a little slot-in moduke (8 solenoids and some simple
linkages), there's a motor-driven camshaft and a couple of external
soenoids for tape feed. IIRC the solenoids in that machine are similar to
the coils used in 'Continntal' relays.
The GNT 34 is suprisingly easy to dismantle, but only if you know the
tricks. For example, the seletor unit (solenoid module) slides out after
releasing a spring catch, the camshaft comes out from one side after
loosening the bearing retainer, and so on. If you try to start by
separating the side plates you get in a mess very quickly (please don't