I have been lurking for a few months - thank you all for the information here!
Thank you, @Uwe, for your wonderful video on timing the 111w155.
I need help finding good sources for 111w155 parts. Good parts, that fit as they should. Not almost good enough.
I received a feed dog rocker shaft [Singer PN 223650], "new".
The shaft diameter of the new part is 12 thousandths of an inch smaller than the original. That is a lot of play at up to 3200 Stiches per minute. Yes, you can feel it.
The bolt for the feed dog lever will not fit into the new shaft, and the new shaft is not threaded. The bolt is 0.3850, and the hole is 0.3775,
a difference of 7.5 thousandths.
Is there anyone that doesn't deal in Chinese crap?