Twin needle question.
My Singer 648 came with a vintage twin needle with an offset shank. The manual for the 648 shows an offset twin needle like the one that came with the machine. New twin needles that I've seen have the shank in the center. This is probably a stupid question but is it OK to use the new centered twin needles or does it need to be offset like original? I don't know that I'll do much in the way of twin needle work but it might be fun to play around with at some point.
Thanks,
Rodney