Tuesday, August 26, 2014

More typewriter mechanism restoration plus card reader hookup


I continued to nudge and exercise the mechanism with the goal of getting all the levers, pivots, rollers, latches etc would move freely. The perpetual line feed (indexing) was soon corrected, but I then found the escapement pawls on the carrier were not snapping into place, allowing the carrier to drift.

Once the escapement snapped into position, the next operational challenge I faced was spacing, quickly changing into backspacing continually. The carrier is now hard against the left rail and I need to get the backspace to unstick in order to continue.

My hand crank tool snapped off due to the resistance from the carrier pushing leftward at the extreme of its travel., It is designed to break before the typewriter mechanism itself breaks, which is good, but it left me with a bit of left-hand-thread screw inside the hole - I will need to extract it carefully (and get a replacement hand crank).

The theory of operations manual describes the way the mechanism accomplishes each action, the illustrated parts catalog shows me the detail of how the parts fit into place, and the maintenance manual describes adjustments and other repair details. Often the theory of operation abstracts out only the parts involved in an operation, such as backspacing, but doesn't show all the other levers and connections that may be part of the assembly I am looking at. The parts catalog gives me the match to the physical reality, then I can look at the subset which are discussed in the theory manual.

I inserted a plug and receptacle into the wiring between the typewriter mechanism and typewriter panel for the power switch local modification. This makes it easier to separate and service the parts of the console printer.


I cleaned out the card reader, hooked it up to the 1131 and began working on it in parallel. The motor and transport mechanism with all belts and rollers seem to be working - in the Non-Process Run Out  (NPRO) mode. It is not reading cards or going ready, except for one time when it read a card into the preread station.

I rebuilt the air filter for the card reader using the filter material I used on the logic gates. The logic card compartment had the disintegrating foam inside the cover, which I stripped off the cover and replaced with neoprene foam. I also removed the crumbled old material from the card compartment and backplane.


I replaced the filter in the Midpack power supply with the new filter material I had used for the logic gages yesterday. I still have to create a filter for the core memory gate (D) but there is no aluminum frame for that part - I have to create a 5" x 18" x 7/16" frame that will hold the filter material.

I replaced a burned out lamp for the Run indicator on the console keyboard and verified its operation.

This was a heavy work day at my day job, leaving little time to devote to 1130 restoration. Tomorrow won't be much better, but later in the week and the weekend I should have more time free to press forward.

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