singer 7-27 bobbin issue

[Gordon25]

Hello, my purchase of my 1915 singer industrial series 7-27 leather sewing machine has been rewarding as it's bits and pieces all cleaned and apparently operational  - but for some reason (and I've been on every trouble shooting site I could find) is that the needle won't pick up the loop from the bobbin and make more than 1 or 2 stitches. I've copied handbook for this machine and followed threading and bobbin winding instruction - to no avail. I've changed needles, threads, leathers, tensions and it does one or two stitches and then refuses to pick up loop. I am wondering if there are specific dog feeder (?) things I need to adjust? I've put in about 9 hours but still getting only a couple of successful stitches. It was clutch motor I've converted to servo with a reduction pulley which all seems to be working. Any (ANY) advice at this stage would be gratefully received. Many thanks from down under.

 

Edited April 30, 2017 by Gordon25
Spelling error

[Uwe]

The Singer 7-27 is a two-needle machine according to the description in the Singer 7-27 part list (7-27_28_38_39.pdf).

That description sounds positively intimidating from a maintenance perspective:

Are you using both needles and hooks? Are you using parts with matching gauges (distance between needles?) If you're only using one needle, which side? There are two different hooks, left and right version.

Are you sure you have the correct hook on the correct side installed? They may fit on either side, but they will only work on their intended side.

A few close-up pictures would be great. Not all two-needle machines are happy sewing with just one needle, and often you can't just install parts for a centered, single needle setup. Without knowing where exactly your machine is at, it's hard to give more specific advice.

As for terminology, we usually say that the hook picks up the loop from the needle to wrap it around the bobbin.

Edited April 30, 2017 by Uwe