Originally Posted by
friquant
Is it only certain types of bobbin cases that jam up if you turn the handwheel in reverse? I've not studied a drop-in bobbin machine in detail until now.
From my understanding, Yes! - Long Shuttle, rotary and oscillating and I believe even transvers shuttle machines. I think there was one machine that could be treadled either direction, but needless to say extremely rare and I haven't been able to find the patent to try to figure out how it worked.. Also there were quite a few treadle machines which had a brake of different types (lever or ball) to prevent the wheel from going the wrong direction.
Originally Posted by
friquant
I suppose the main use cases for moving the handwheel in reverse would be:
1. Upon finishing a seam, but the take up lever went a little past top dead center, so I want to move the handwheel in reverse to put the take up lever back at top dead center before pulling the goods out from under the presser foot.
As cashs_mom said, one can take a stitch or two beyond the edge of the fabric. OR can use leaders/enders or spiders to begin and end seams. It tells about these at
https://flourishingpalms.blogspot.co...nd-enders.html
Originally Posted by
friquant
2. Upon finishing a seam, after bringing the take up lever to top dead center, but when the material is rather thick then I might move the handwheel in reverse to bring the needle to its top dead center so the needle is not sticking into the material at all.
Here again one could use leader and enders or spiders to move the seam past the presser foot. Also, I think that they should be coordinated and if you are using a fabric that is so thick that this is not the case, than you probably shouldn't be using it on that machine.
Originally Posted by
friquant
3. Sometimes if there's a thread jam I want to rock the hook back and forth gently while tugging at the errant threads to pull them free.
While I will admit to rocking the handwheel to free a thread jam, not more more than a couple of degrees and certainly no more than that.
Originally Posted by
friquant
4. When using the marks on the needle bar to set the timing, if I go a smidge past the mark I would want to go the other way to bring it back to spot on.
Fortunately I have never had to actually time a machine, by setting to the mark on the needle bar, that really does not make sense to me as to why you would want to turn the handwheel in a direction other than what was intended.
There are some machines that the handwheel goes the other way, but you always want to turn the wheel the way that it was intended to sew.