Sewing Machine Timing

D Vautier
4/23

My son had a bunch of canvas for his boat that needed sewing because boat canvas is extremely expensive and requires custom work.  So he got some V69 marine thread and some industrial needles.  Now V69 is really strong stuff and I was not sure how long my little portable singer would last.  The automatic needle threader did not work at all but Val had laser vision and threaded it manually.

Sewing machines date back to even before the industrial revolution because they don’t need much power.  When I was a kid we had a peddle job which was immense fun to peddle as fast as we could.

The idea of sewing machines is really simple. A threaded needle pierces material.  One side of the needle has a groove from shoulder to eye.  As the needle begins to withdraw it leaves a loop.  That loop is caught by a revolving hook which carries the thread around a spindle (bobbin holder). An arm on top of the machine allows the thread to play out and then pulls the thread back in. That's it. 

We got about half way through our project before the poor little machine broke down; actually it just lost timing.  That’s because a grooved belt synchronizes the top arm action with the bottom and it probably skipped a few notches during the struggle.  Anyway when I looked at the machine the timing was way off.

I looked up the exact specs by singer but I felt they were wrong.  They said to set needle at 5 mm from bottom of stroke. The needle has to be in the up motion when the hook comes around, but the distance did not seem right.  So I brought the bottom of the needle eye up to a point 5mm (1/4 inch) below the hook as it just came by.  We tested this setting and it worked fine so we finished the job.