The cause of the perpetual print cycles was a small spring for the restoring lever, underneath the machine, which had come loose when I connected the cycle latch lever spring a few days ago. After putting it back in place, the machine does not attempt print cycles when not requested.
|Hand cycle wheel in place - apologies for the blurry focus|
|Spring hook tool used to affix small springs|
|Hooverometer in approximate position for cycle latch adjustment|
|Hooverometer tool for adjusting Selectric typewriters|
In spite of this, it is still not restoring and thus taking perpetual index cycles. I will need to investigate this further, after I spend quite a while poring over the theory of operations, adjustments and illustrated parts manuals.
I adjusted the red ribbon shift tape tension to get the new replacement tape I installed working correctly. Nothing in any of the manuals advises on tape tension or setup. You loop the tape around and then have to guess how much to move the right hand tape pulley in order to have black or red print depending on the selection.
|Right pulley with plastic ribbon color shift tape, adjustment screw at right|
|Armature to pull or release the ribbon color shift tape|
|Tape snapped off the metal clip|
|Clip pushed through doubled section of tape, makeshift repair|
|Cam follower latch in its leftward (black color) position|
|Cam follower latch in its rightward (red ribbon color) position|
The two solenoids that activate the carrier return and index functions have microswitches that detect the state of the operation, with long leafs on the switches that extend out and can be touched by metal bars on the actuator arms (they are called contact bails).
|Carrier Return microswitch with leaf below bail|
|Index microswitch with leaf above its contact bail|
NEW KEYPUNCH INTERFACE DEVELOPMENT
I retrieved all my design notes from the workspace and began to properly assign all the signals to the Arduino pins. From there, I resumed writing the startup code to initialize the interface. The punch and the reader cables each have a pair of wires connected together, allowing the Arduino to do a quick verification that the respective cable is attached. If the reader cable is not installed, the unit will still work as a punch but cannot read cards or verify during punching.
The USB serial port is used for diagnostic messages - both normal status and errors - in addition to the text responses on Serial port 1 - the user interface - to every command issued on that port.