Friday, May 27, 2016

Jam removed from punch, discovered one of 12 punches had fallen out


The 1053 has three buttons across the front, which invoke space, tab and carrier return, in addition to the solenoids which command these three functions as well as line feed and backspace operations.

Two of the buttons trigger tab, although one of them should only be invoking a single space operation. I also have some remaining issues with the return skipping over the left margin stop and jamming. This may be more gunk from the residual bad lubricants used by IBM years ago, which do not age gracefully.


It is definitely the punch for row 0 that is stuck down in the die. I suspect that I will have to remove the funnel for the chips that fall, then remove the punch die in order to free this up. The goal will be to install it properly so that the punches slide smoothly in and out as they go down and up.

After removing the funnel and the bottom plate, I still had a serious blockage. I decided I had to remove the punch unit from the 1442 chassis in order to work on this. Second time around, removal was quicker.

Punch removed from 1442 chassis once again
Looking into the throat made it clear that I did have a major card jam, not just a stuck punch. It took me a couple of hours of careful prying and sawing and maneuvering with a keypunch card saw before I got the jam cleared. At that point, I noticed the reason that my original symptom was lacing with rows 4 to 8  but not row 9. The punch for row 9 is not descending.

Jammed card visible in throat above wheel
I suspect that this is the funny U shaped part I found. I am going to have to disassemble this much further in order to get to the punch and repair it. Worst case, I may have to manufacture a replacement part if some part of the punch has snapped off. The parts catalog and repair manual pictures are useless to determine what this U piece is or exactly what the punch parts look like.

Using the instructions for replacing an individual punch, I began removing parts from the punch unit to get to the row 9 punch. As soon as the last parts come off and gave me a direct view of the punches, I confirmed that the U piece is indeed a punch.

Punches visible, leftmost (row 9) is missing
The punch which fell out
The U piece, with its two legs much longer than the crosspiece, is how the machine punches holes. The two prongs cut the hole in the punched card, sliding down into the die. A spring pushes them up out of the die, but I don't yet see the springs to know how they attach.

The cross piece on top is what the interposer fits against - the interposer has a ledge that allows the crosspiece to sit against it and be pushed down as the interposer is pushed down. Above the interposers is a wide bar, the bail bar, which is spring loaded upward and forced down by the main punch cam roller when it is time to punch holes.

I think I have an intact punch and only need to fit it back into the die, but the angle is (of course) quite awkward for maneuvering a small piece into place. I chose to wait for another day when I am fresh before attempting the insertion of the row 9 punch, after which I can carefully reassemble the punch unit.

Once I am sure that all twelve punches descend properly, the punch can go back into the 1442 chassis. One of the dis-assembly steps before replacing an individual punch is to remove the solenoid assembly, so I need to readjust those once again.


I received more information on how a fellow enthusiast recreated the pen and solenoid assembly that was missing from his Calcomp plotter and which I am also missing. These show much more detail on how to machine the various parts. I am hopeful that this is enough to proceed. In addition, he has videos of all the steps which are available if I need them to resolve any questions during the process of manufacturing.

Still no word from the metalworker so time to find a plan B for building a replica of the bent drum.

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