[vcf-midatlantic] Workshop after-action report (IBM 029)

Mike Loewen mloewen at cpumagic.scol.pa.us
Mon Feb 29 19:23:49 EST 2016

    For the 2/27 - 2/28 workshop, I did some more work on the museum's IBM 
model 29 keypunch.  When I first powered it up, it didn't do much of 
anything except run the motor.  It gradually "warmed up" and started 
punching, but was obviously in need of lubrication.  I cleaned and 
lubricated many maintenance points, which quieted down the machine and 
made its operation much smoother. I used Tech Rubber Roller Restorer to 
clean up the rubber feed rollers.

    I replaced my home-made arc suppression board with a spare from the 
warehouse.  I also replaced the punch clutch pulley belt, which was ready 
to fall apart, and substituted a much better looking program drum.  I 
adjusted the two pressure rail microswitches in the card bed, and cleaned 
and lubed the keyboard to fix some sticking keys.

    During the process, the machine developed another fault: each time a 
card would "register" at the punch station, it would automatically be 
"released" and sent to the read station.  After several hours of 
troubleshooting, I discovered a broken wire leading to the escapement 
magnet assembly.  It had been hanging on by a thread, causing erratic 
operation, and eventually completely broke away from the spade lug. I 
soldered it back on, and the machine was again punching.

    The very last thing I checked was the function of the sensing pins in 
the read station, by trying to duplicate a card.  Not all card rows were 
consistently read, but improved with repetition.  Unfortunately, I ran out 
of time at that point.  I had lubed the sensing pins, but they need 
another round of cleaning/lubrication.

    At this point, the keypunch is useable for demonstrations in the
museum room.  The print mechanism still needs work, and doesn't print
all of the characters correctly.  Cleaning and aligning the print
unit will be a major project.

    I multi-punched a VCF EAST 2016 card and left it on the punch.

    Oh yeah: I also pushed an IBM printer for a 1/4 mile.  :-)

Mike Loewen				mloewen at cpumagic.scol.pa.us
Old Technology				http://q7.neurotica.com/Oldtech/

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