Singer 31-15 Worn Tension Release Lever

[Ogoki]

Yes, exactly, it is a completely different mechanism from the foot-lift-tension-release, although they both release tension via that same lever.  This 44-79 would have been meant for stitching leather gloves, so who knows.  Thanks for that info, @RockyAussie

[RockyAussie]

I just found an interesting bit on Pinterest that shows a bit on this. Link attached. It may contradict what I've said but I still would not be sure. Thought it worth a look anyway-http://www.theprojectlady.com/2016/07/industrial-singer-31-15-sewing-machine_7.html

[Ogoki]

Thanks for the link.  I have seen that article before.  Nice restoration pics.  However, she is still referring to the gap to the right of the lever (between lever and pin), and to the release of tension that coincides with foot lift.

[Wizcrafts]

I own a Singer 31-15. When I raise the foot, either by the hand lever of knee lever, at a certain point the U-shaped crank gets rotated to push the pin that pushes the tension release to separate the disks. That is how it is meant to work. The gap between the crank and pin can be adjusted to fine tune when and how much the disks separate. The disks should not separate during normal sewing operations. If they are doing that, something is wrong with the positions of the parts that affect this action.

Also, don't try to sew more thickness than the machine is designed to handle. My 31-15 is good to a little over 1/4 inch. It can lift higher to clear the material, but not to sew it. This machine uses DBx1/1738/16x257 system needles which are too short for thick sewing operations.

[Darren Brosowski]

People have raised this issue before and for 99.9% of machines it is BS.

I have a PFAFF "basting" machine where the tension is released in sewing but it is designed to move the material pulled through by hand doing a large stitch. The purpose is to hold the fabric together while other processes are done then the basting stitches may be removed