Verification of 1053 Console Printer controller electronics - part 4

FIXED ISSUES WITH THE SHIFT TO RED/SHIFT TO BLACK COMMANDS

After some tweaks, the solenoids do adjust the ribbon color string tension under the command. I still need to tweak the string tension to get the printing to come out in the desired color. 

NOT DONE FIXING THE AUTOMATIC SHIFT BETWEEN CASES

The shift magnets are another area of the machine where adjustments require many many hands simultaneously, thus the proper setting requires sneaking up on the solution incrementally and often in the blind. 

The upper case magnet has to be adjusted on its bracket left/right, up/down and rotationally in order that the solenoid leave a necessary small clearance to the shift mechanism roller when unactivated but when it is activated, the roller has to be moved a fairly precise amount otherwise the shift clutch won't stop at the upper case position.

This last issue was where I left off at the end of the day in the shop. The adjustments I had painfully accomplished did fire off a cycle to shift from lower to upper case when I was printing a character that was on the upper side of the ball when the prior was not. I watched, however, as it shifted printed and went right back to lower case.

One needs a hand to hold the upper magnet in its orientation, another hand to hold its arm in the fully energized position, a third hand to hold the screwdriver to lock it in place, and a fourth hand to hold the feeler gauge that checks the shift arm fit with the clutch stop. 

Once in a trial position, you need a hand to hold it in the open position and another to check the minimum arm to roller gap; this one is easy but if the minimum isn't achieved, iterated with the UC magnet position until you can achieve both of the conditions.

The lower case magnet is always installed in relationship to the upper magnet. It has to hold the upper case magnet's arm in place at the fully energized position so that the clutch will stop, but it needs to have a clearance so that it will slide over that arm as the UC is engaged. It has to clear the UC arm when the lower case magnet is energized so that the UC arm can swing back to the idle position. Note that the UC arm must have the mandatory minimum clearance from the shift roller in this case. 

Finally, both magnets must be in a position where the gap between the solenoid pole and the arm is not too big, otherwise they won't activate with the short pulse coming from the controller logic. 

To set the lower case magnet in its position, you need one hand for the magnet, one hand for the screwdriver to tighten it, another hand to hold the UC armature one way, another hand to hold the LC armature in the opposite state, and a final hand for the feeler gauge to check clearance. Do this until the pair reliably latch in the two states, because of the interaction of the arms.

I was close but not close enough, achieving all but one objective. I should wrap this up tomorrow.