[GreenKeys] ASR-33 problem with clutch

[Aaron Nabil]

On Mon, Jul 28, 2008 at 2:32 PM,  <Teletypeparts at aol.com> wrote:
> It should not make any difference what character you type.  The problem is
> probably the selector cam is dragging, needs some oil on the main shaft btween
> the cam and the shaft.  Oil the main shaft on the far right side of the cam and
> also in the small hole in the cam near the rangefinder bracket if you can
> find it.


I found the hole and shot in a bunch of oil.  The cams turn even more
freely now.  Didn't help.  If anything, it's the fact that the cams do
turn so freely that is the problem.  There is a detent-like force (I
think it's from the SPACING LOCK LEVER CAM or the STRIPPER BAIL CAM)
that is much stronger if the last character typed (more BLOCKING
LEVERS up) is a rubout (vs a null) that tends to turn the cam slightly
forward and over-open the clutch.  It's not a lot of force, but the
cams turn so freely it doesn't take much to rotate it.

What I did as a stop-gap measure was turn the rangefinder to 47 (was
64). The stop lug still stops in the same place, but now the shoe
lever is stopped further along, so the clutch doesn't get over-opened.
 I probably didn't need to do this as the drag is very slight and only
happens on few characters (I would have been more concerned if CR or
LF caused it to drag) and my TTY sees between little and no user, but
at least now I don't have to worry about leaving it running.  I just
ran a bunch of quick brown fox with my test set and it copies fine, is
there any reason to worry about having the rangefinder advanced so
far?

I'm going to go look at another teletype for reference.  I'm wondering
if something isn't resetting as the blocking levers stay up after a
character and they move slightly down as the selector cam drifts
(after it has stopped with the clutch open) maybe the STRIPPER BAIL
CAM isn't working.  It's odd that it otherwise works perfectly, and
that there are two that act like this (and that they are both
virtually new units).

Thanks and call anytime.

Aaron