12 Oct
2009
12 Oct
'09
4:29 p.m.
Tony Duell wrote:
The carriage is moved bu the toothed belt at the
front. At the left end
of this is the drive sprocket, bolted to a ratchet wheel. There are some
pawls (2, one for moving it, one to prvenet it running back?) that
operate on this wheel. They're lifted off the wheel during a carriage
return (so the spring can pull the carriage back to the left) and them
drop back into engaagement on the next character (IIRC). I'd start buy
checking this area. Maybe something is bent or out of place.
Doesn't look like the pawls (or at least one of them) are engaging:
http://vintagecomputer.net/teletype/asr33/2009/ASR33-1.jpg
It's hard to tell, but it looks to me that either the pawl is too low to
catch the ratchet gear, or it's standing proud of the gear. If the base
metal (or the pawl) were a different colour, it might be easier to tell..
This image implies that it's just plain disengaged, though I can't tell
for certain what angle it was taken at (whether it's showing the
frontside 'ASR33-1' view, or the opposite side):
http://vintagecomputer.net/teletype/asr33/2009/ASR33-8.jpg
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
