"William Sommerwerck" wrote in message
...
I get everything back in place and work the mech by hand, and all ok,
so I put it all back together again, and now it plays in forward, plays
in
reverse, but when you stop and try to play forwards again, it cuts out
because the trailing spool isn't going round. Why? because there is now a
small loop of tape in the cassette that's just long enough to not be
taken
up before the autostop cuts in. And why is there a loop ? Because as the
mech comes to a stop, it just for the tiniest moment 'flicks' the take up
spool in the 'wrong' direction. And why does it do that ? **** knows is
the
simple answer ...

If I understand your description correctly... it shouldn't matter whether
it flicks the take-up spool, because the "correct" way to design an
autostop system is to wait until the takeup hub stops turning. This is the
way Sony's WM-D6C -- and doubtless hundreds of other cassette decks --
work.


Yes sorry. Senior moment. It's the *supply* spool that it momentarily
flicks, and the tape counter - and hence the autostop - pulses are derived
from that spool rather than the take up spool (in "forward" that is, because
in reverse play, the supply spool of course becomes the take up spool ...).
So it's fine in reverse play, rewind, and wind - because it's quick enough
to take up the slack and get the supply spool turning - but not in forward
play, because the capstan / pinch roller is pulling the tape slowly enough
that it takes probably 2 seconds to clear the loop, and the autostop trips
in probably 1.5 seconds. And of course, what does the autostop do ? Why, it
stops the deck, of course, and what does that do ? Right. It flicks the
supply spool and throws out another 2 seconds' worth of tape ... VERY
frustrating. You can make it play by hitting FF and then immediately hitting
play. No loop then and the supply spool is providing tape counter / autostop
pulses right from the off.

Arfa