[GreenKeys] grunting 28 KSR?

[George B. Hutchison]

Gene and GreenKeyers - - -

Gil has the closest call when it comes to the "grunting" in the
machine.

The model 28 clutches have to be latched after every rotation in
order to not damage, or in extreme cases, fry the clutch drums and
shoes.

The clutches all must have sufficient inertia when the clutch stop
comes around to disengage the clutch. If the clutch is not spinning
fast enough, typically 60 WPM is where the problem will most often
occur, then when the stop latch attempts to complete the
disengagement it does not have enough oomph to successfully latch up,
and the clutch will drag, sometimes giving a zizz-zizz-zizz sound, or
a sort of moan when it does not completely disengage.

The clutches are not that hard to adjust, but it is almost vital to
have a J1 wrench to get it right.

The ideal distance between the clutch stop lever and the clutch latch
with the clutch engaged is about the thickness of a J1 wrench. The J1
is also just the right tool to get into the gap between the clutch
body and the clutch drum so as to be able to loosen the two 3/16"
screws which allow adjustment of the clutch.

Too wide a gap between the clutch stop and the latch will permit the
possibility of the clutch stop lever falling between the stop and the
latch, causing things to sometimes come to a screeching halt, with
sounds and smells akin to a fire in an oil refinery. The clutches can
get so hot that they will turn black, and the hardness of the clutch
shoes and the drum will just go away, making replacement of the
entrire clutch and drum mandatory.

I believe the Bell System Adjustment book on RTTY.com has some clutch
adjustment info.

The motor problem sounds like either the motor start capacitor has
failed or the motor start relay is  defective. These items reside in
the square housing underneath the motor. Easiest solution is to
replace the motor with a known good one.

73,

George - W7TTY