Freeing up 1132 printer components - part 8

FINISHING THE PRINT CLUTCH LATCH LEVERS

The oil worked overnight and with just a bit more work, all the levers move freely. 

FINISHING THE PRINT CLUTCH CAM AND CLUTCH DOG WORK

Most of the mechanism in the printer is lubricated by spraying IBM #6 oil on the parts without disassembly. However, the flutes of the Print Clutch Cam Shaft should be lubricated with IBM #17 grease. I have modern replacements for these lubricants. 

Thus, I began from the right side, making sure every Clutch Dog pivoted freely, that the Print Clutch Cam rotated around the shaft when the dog tooth was not engaged, and then sliding it against the finished Cam disks. I would grease up a section of the shaft and then process Print Clutch Cams until I had mostly filled that area. Below is a picture with a section of the shaft having been greased, before working on the Print Clutch Cam disks to the left of it. 

The maintenance manual recommends engaging the comb to keep the Print Clutch Cam disks in their proper spacing. It is also supposed to keep any Print Clutch Dogs from popping off their pivots. I hooked up the comb as suggested, but my initial packing of the Print Clutch Cam disks was too tight together requiring me to massage the parts to fit in the comb. During that work, two Print Clutch Dogs popped off their pivots. 

I believe I can reset the dogs onto the pivots once the shaft is back in the machine, so I will leave the two dangling for the time being. 

It is time to reassemble the printer mechanism, adjusting as I reinstall to prepare it for hand testing and eventually testing hooked to the IBM 1130. 

CLEANUP AND TESTING OF THE CARRIER ASSEMBLY

The carrier assembly has an electric motor, a gearbox, clutches, two solenoids, and the carriage control tape mechanism. First up was a cleaning - removing nut shells and other infestation consequences. I then checked the lubrication and movement of the gear box and other key parts. 

The gear train is very stiff - solidified lubricants at work - and needs much work to free up the rotating parts. 

POWERING THE CARRIER WITH A 48V BENCH SUPPLY

The carrier motor runs on 48VDC as do the solenoids that engage either single space or skipping movements. I used a bench supply and testing the motor. It attempted to turn but the high friction of the gearbox was too much for it, even with 50W delivered to the motor. I will test again once I get the mechanical parts freed up. 

CARRIAGE CIRCUIT BREAKER (CB) FROZEN AND LOOKING CORRODED

IBM uses the term Circuit Breaker (CB) for a switch that activated by moving parts - either activated by cams or in this case by a plunger popping up and down in slots around a gear. The CB will send a pulse at each line position as the carriage moves - the slots are spaced to produce six lines per inch vertically on the print forms. 

The metal leads for the switch contacts look very corroded and blackened from the acidic rodent urine atmosphere. The spring loaded plunger is frozen in position up in a gear slot. I will have to free up the plunger motion and then either clean the contacts or replace them to get this key CB working. It is how the carriage knows to stop after spacing one line.