Singer 51W54 Thread size conundrum

[Davidmadd]

Hi All

I have a Singer 51W54 that appears to be in fine fettle.  It is a wheel post feed machine.  It stitches just fine, but only if you use the lighter threads.  I've been experimenting with thicker threads as I want the threads to form part of the decoration on one or two bags I'm planning in canvas and leather.  Now the bobbin mechanism, bobbin size etc appears to be identical to my 111w154 and that machine copes very well with the thicker Bonded Nylon threads, this thread is marked M20. However when I try to use this same thread as the upper or lower thread on the 51W54 it just will not accept it.  When I go back to the finer threads the stitches form just perfectly.  I have read on this forum previously that this is the case with this machine but I just dont understand why. As I said, it seems to use the same bobbin mechanism as the 111W154 which does sew with the larger threads.  Would that perhaps indicate that its the needle side of the equation which is not coping?  Any thoughts please.

David 

[Wizcrafts]

While it uses a similar size bobbin and shuttle, the clearances are far smaller than on your walking foot machine. Everything is tighter in those ancient post machines. I used to own two of them and could only get them to sew reliably with #69/T70 bonded thread, tops. Anything larger got pinched and jammed everything up.

I would stick to using a #110 needle, with T70 bonded thread, as the maximum. Make sure that if there is a latch opener that it pulls the bobbin case back far enough to let the top thread pass freely around the positioning tab on the case, under the throat plate. Give more thread slack in the check spring. You may get lucky and fool it into passing #92 thread, but you'll need to find a #19 or #20 needle to sew with it.