Zig zag Timing Adjustment of Singer 237 Sewing Machine

I had a problem with missed stitches at the right side of the zig zag stitches with the Singer 237, when sewing heavy fabrics. I have checked everything and adjusted according to the service manual. It did not help. Then I diagnozed the problem and did a bit of advancement of the zig zag timing, and it solved the problem. This video explain the details. List of contents 0:00 Intro and skipped stitches 0:53 Mechanics of side loaded zig zag machine 1:45 Advantage of side loaded sewing machine 2:07 Continued explanation of mechanics 3:58 Needle movement and reason for skipped stitches 5:24 Advance in zig zag timing 6:38 End The Singer 237, and many of the Vintage Necchi and Japanese zig zag sewing machines got this kind of mechanics, and it is very different from most other machines. However this design makes these kind of machines better to handle heavier materials than the normal front loaded zig zag machines. You can get many vintage sewing machine manuals for free via ismacs.net. The service manual for the Singer 237 can be found from this link: https://ismacs.net/singer_sewing_mach... Andy Tube have made a detailed video about the zig zag mechanics here:    • The Zig Zag Slide and Traveling Hook Syste...   Please "like" this video, if you find this information useful. You will probably find other tips for your sewing machine on my youtube channel. Leave a question and a comment as you like.