Thursday, February 29, 2024

Adjusting the rotate character selection on the 1053 - final round part 2

CAREFUL ADJUSTMENT OF EVERY ITEM IN THE PROCEDURES

I prop up the front of the typewriter to have access to the selection magnets underneath which are used to trigger printing a character. Often I have to stop the hand cycling at a point such as when the detent begins to lock down the ball position or when the check pawl drops into place at the end or middle of a print cycle. This involves rotating the typewriter to see those areas.

Propped up 1053 allowing access to underneath

Selection magnet bars 

Setting the initial home position requires that the setscrew be loosened on the underside of the shaft that rotates the typeball. One has to put the typewriter on its back with the carrier all the way on the left and then use a very long bristol wrench driver to loosen and tighten the setscrew. 

Top of typewriter on left, wrench used on setscrew

Turning ball while setscrew is loose

ROTATE ARM POSITION AND PIVOT

The resting position of the rotate arm lever is the position where the typeball will sit for the 0 rotation column, called the home column. Further, its pivot point determines how much the ball twists as the lever arm tilts a particular amount based on the R1/R2/R2A/R5 selection levers. We adjust to get good selection of both negative 5 and positive 5 columns. 



BALANCE ARM MUST BALANCE NEGATIVE AND POSITIVE ROTATION AMOUNTS

The R5 lever pivots a lever that works in the opposite direction to the other selection levers (R1, R2A and R2). This lever is activated when its selection magnet is energized. The other rotate levers are activated when their magnet is NOT energized; the magnet operation causes the lever to be removed from the bail so it does not move down.

If only the R5 lever is activated, with the other three magnets energized so that the levers are NOT active, the ball rotates to the -5 position. If R1, R2 or R2A levers are activated because the selection magnet is off, it pulls down with the bail and offsets some of the negative movement of R5. In a sense it is signed addition, where the R1 lever moving down at the same time as R5 will add a +1 and the -5 to select a rotation position of -4. 

To ensure that the amount of position and negative movement is the same, the balance arm must be adjusted. This is accomplished by comparing the position of the ball when no levers are pulled down (R1, R2A and R2 energized, R5 not), to an alternative called IO Home. 

In the first case, no levers are pulled down the the bail so the ball does not turn at all. In the second case, we do not energize R1, R2A or R2 but energize R5. The first three develop a +5 movement and the R5 adds a -5 movement, thus arithmetically zero. 

If the ball is in the same position in both cases, then we know that the +5 motion of R1, R2A and R2 are exactly balanced by R5. The parts of the balance arm are slid together or apart to achieve the balance we want. 

Balance arm with R5 on right and the other levers on left

I was NOT able to get the balance arm to completely zero out the differences between the two types of zero. I adjusted it as close as it could get but ultimately the rotation of the ball is not correct because of this. 

TYPEBALL FINAL ALIGNMENT

The type ball home position is adjusted again by lengthening or shortening the pushrod that couples the whiffle tree selection mechanism to the rotate arm, moving it in or outward. This must be done to ensure that the detent teeth are entering at the right point in the triangle. This assures the most reliable character selection in spite of minor variations in the amount of tilt and rotation in a particular print cycle. 

PRINT SHAFT FINAL ALIGNMENT

The print shaft is rotated relative to the print cycle shaft to cause the detent and striking operations of the carrier to happen at the best possible time in the print cycle. One gear is loosened and the shaft is turned by hand to reach that point, while observing the operation of detent teeth. This is the ultimate adjustment for character selection. If done correctly the typewriter should reliably select the correct character from among all 44 on a side every time it prints. 



Gear on top is loosened to adjust print shaft timing

RESULTS NOT SATISFACTORY

In spite of being very careful and thorough in going through the settings, without having the balance lever set correctly it was not possible to have the ball rotate reliably to both +5 and -5 positions. These were the symptoms I started with before I began the adjustments. 

I tried to adjust other areas to compensate but I am fairly convinced that the balance arm disparity is the smoking gun that is either the cause or indicating the root cause of the issues. I will have to study the parts from the donor typewriter, compare positions and appearances closely between the working this 1053, and get this resolved during my next session at the shop. 

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