Monday, December 15, 2014

1053 Console Printer work

Some health problems have arisen with my father-in-law that took up some time today and likely will take me away from the 1130 restoration from time to time, but not continuously.


I realized when I started on the 1053 this morning that I had two adjustments left to make, not just one. After I set the final print shaft timing, I need to set the contact switch that gives feedback to the adapter electronics about when the print operation is complete to the point where another character or operation can be requested.

Shift interlock cam on filter shaft 

Escapement cam - spaces after each character printed - on filter shaft
The print shaft timing involved setting the timing for when the detent first contacts the notches along the bottom of the type ball, so that it is safely inside the notch but on the side - this gives the detent a 'wiping action' as it moves to the center of the notch with continued rotation of the print shaft.

Gear train - print shaft on top (smaller black pulley)

Print shaft going into carrier at right, cycle clutch and drive belt visible below

Black detent bar entering notch in typeball, barely visible 2/3 of way to right along bottom of pic

The C-2 contacts ride on the cycle shaft gear body, ensuring that the timing of the cam climb point and slope is synchronized. However, the vertical position of the contacts determines exactly where the switch closes and opens relative to the rotation of the cycle shaft, as it moves up or down the slope.
Carrier from top while standing behind printer, sliding on print shaft and along escapement bar

The open and close points are easy to set by reference to the degree wheel affixed to the left end of the cycle clutch shaft - sits at 0 when at rest, then marked in single degrees for the 180 degrees of one cycle.
Degree wheel mounted to end of cycle clutch shaft
To adjust the print shaft timing, I put the Hooverometer in place to block the cycle clutch at the halfway point (half-cycling a character), selected a specific character by pushing the appropriate solenoid arms down, then rotated the hand crank wheel. The gear on the end of the print shaft is held in place by setscrews; loosening them allows the shaft to be turned to advance or retard it compared to the cycle shaft position.

With the machine stopped at the half-cycle point (registering 90 degrees on the degree wheel which matches the state of the clutch shaft), the print shaft is turned to spot the point where the detent bar engages the teeth of the typeball.

However, as I did this, I could see that the ball was not properly rotated. The notch of the teeth was offset so that the detent bar could land directly on the crest of the tooth or even snap into the wrong notch, depending on the rotational play of the typeball.

Now I have to go back and validate the rotation mechanism settings, before moving ahead. The current mis-positioning can cause breakage of the typeball teeth or damage to the typewriter mechanism.

Rotation of typehead controlled by movement of this vertical arm, thru the rotate tape on pulley

Tilt of the typeball controlled by this vertical arm, thru the horizontally mounted pulley for the tilt tape
Selection mechanism that converts various solenoid latches into movement of the tilt and rotate arms

Another anomaly I see occurring is sporadic failure of the left margin to stop the return of the carrier, which seems to be caused by sludge in the margin bar and sliding components attached to it. I exercised them a bit and seem to have a more reliable left stop now, but will keep my eye on it.

Under power, the motor still vibrates a bit which is caused by the corrosion on the motor pulley, such that the belt does not slide into the corroded slots as fully as the normal ones. I need to locate a good replacement and install it before the new belt also is damaged. I think I understand why the typewriter was modified with a power switch on the front panel - the vibration and miss-adjustment of the typewriter would be objectionable but turning off the motor removed the problem symptoms (but the console printer could not be used in this case).

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