How to modify your Singer 237 Sewing Machine for heavy duty work.

The video explains briefly the modifications to a Singer 237 sewing machine in order for it to sew with heavier thread up to V138 polyester thread. You will find more detailed descriptions of the modifications on this YouTube channel. List of contents 0:00 Intro 0:18 Grinding thread U-turn on shuttle hook 0:30 Stronger beehive spring in tensioner 0:45 Speed reducer 1:14 Explanation of the zig zag mechanics use service manual 3:32 Advance of zig zag timing 3:43 Replacement of race gate 4:31 Increase in reverse stitch length 4:40 Changed thread guides 4:58 End I got a new race gate from this supplier: https://www.vintagesingerparts.com/pr... WARNING: Many skilled sewing machine people argue, that you may wear down your vintage sewing machine by the modifications and heavy work I present. Therefore you shall be warned. I have not yet seen wear on my machines after having sewn about 3000 m of Tex 135 thread. 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.