This is the heart of automatic patterning on a Silver/Singer/Studio punchcard machine. As the carriage passes the punchcard mechanism, the Memory Drums record the position of the holes in the card. On the return pass of the carriage, the appropriate needles are selected and positioned according to the Cam Setting (stitch technique).

NOTE: Often on machines that have been stored for a long time the memory drums can be locked up. The drum should turn freely for stitch patterning to occur.


NOTE: The memory drum "remembers" previous positioning even if you remove the punchcard. To clear the memory drum memory, remove the punchcard and leave the mechanism engaged. Pass the carriage a few times to reset it, then cancel patterning.