Escapement

I worked on the 328K some more today and finally decided that I would just live with whatever was making that "whisper" in the bobbin case.  I put the machine all back together and cleaned it all up.  But the tension assembly was filthy and I just couldn't live with THAT.   I could not find the set screw to release the tension stud so I just took the parts off with the stud still in the machine.  I found the set screw once I had all the parts off.  You must access it from above.  I decided that I could just reassemble the thing without all that bother.  The check spring isn't quite right, but.....

Once I had the machine all back together, I tested the stitch.  Omigosh.  There was an awful racket from below.  I was sure that I had not pushed the position bracket back into place.  Nope.  All was fine.   The top tension felt terribly tight.  I took it apart, AGAIN, honed the discs and reassembled it. (Which is why the check spring isn't quite right, it was perfect the first time).  Still no better.  I took the slide plate and the needle plate off and watched the thread as it made its journey.  It was catching in two places.  First just along the bobbin case  and again in the back. 

Work with me here,  imagine that there is a bobbin in the machine and there is thread catching along that path.  The answer to the problem is in this photo.  The clue is in the title of this post. 

In order for me to see where it was catching in back  I had to remove the feed dogs.  which I did .  Then I figured it out.

I had tightened the bobbin case position bracket too tightly and there was NO ROOM for the thread to escape along its journey to making the stitch.  In this photo there is some space space between the bobbin case and the position bracket.  I took this photo yesterday before I started messing with the machine.   This space is the escapement.  There MUST be space there, or thread will catch.

I thought that the bobbin case sounded too rattly so I tightened it up.  Too much. There was NO SPACE there after I made the rattle go away.   I moved it back and the machine stitches.  Yes, it is noisy.  It is not as quiet and smooth as the 401 or the 301 or the 201 or even the Janome 2212 (Omigosh I am comparing a Vintage Singer to a plastic modern machine.  Blasphemy!)  But it makes a very nice stitch.  Tomorrow I will adjust the tension and find a zz cam for it and post it for sale.  Or not. 
(No, the whisper was not the noise of the position bracket rubbing on the bobbin case.  Those two pieces are stationary)