Singer 211U566A Matching forward and reverse stitch length

[SPF]

Hi Everyone, this is my first post, but I have been researching information on this site for a while. This forum is an awesome resource, and thank you in advance to anyone who can provide any information. 

I have purchased a Singer 211U566A in the last few months and it needed some work because some of the parts in the needle feed and walking foot mechanism were flogged out, and had been poorly repaired. I pulled the machine apart and rebuilt it after not being able to locate various noises, this is all done and the machine is now working well. While repairing the machine I noticed in the service manual that the reverse stitch length on these machines was limited to 5mm, even though the forward stitch length maximum is 8.2mm.

At some time in this machine's history the limiter block that I assume stopped the reverse stitch length exceeding 5mm has been ground off. After some adjustment, the stitch length in forward and reverse is matched from 8.2mm down to 2mm. The machine does not seem to bind, or have any issues at any stitch length. Also, thanks to Uwe for the stitch length gauge printout, which is very helpful for getting this done.

So my question is, does anyone know why the reverse stitch length was limited on these machines to 5mm. And, if I continue to use it with the current adjustments, am I going to flog out any of the mechanisms? 

[Wizcrafts]

Could you please post a close-up photo of the altered part that allows for longer reverse stitches?

[SPF]

Thanks for your response Wiz.

In the photo below, the modified part is inside the red hoop, and the part with the arrow next to it now clears by about a paper thickness and swings past.

[SPF]

Sorry, should also have said, that when I push the reverse lever down, so that the feed regulating fork link stops at the block, where it would have stopped (with no modification), the reverse stitch length is very close to 5mm.

Edited May 24, 2021 by SPF

[SPF]

Any feedback would be appreciated, if you need more photos, please let me know.