Mitsubishi DB stitch length acting up when using reverse

[DrmCa]

On my machine, the stitch regulator pin is broken. It does not have the thin section that lives inside the spring (pointed at by the arrow), and its tapered end that contacts the regulator knob is worn. I slightly sharpened it, on a lathe, and it holds slightly better ever since.

When I go into reverse, the stitch length knob sometimes turns all by itself. I lived with this issue for quite some time because I can simply keep an eye on the knob and turn it back, but since I was ordering parts from College Sewing anyway, I bought the replacement spring, with the idea in mind to turn my own pin. The problem is that now that I compare the old and new springs, the new one from CS is shorter and weaker.

I cannot understand how a shorter and weaker spring can keep the knob from turning any better.

[nylonRigging]

20 hours ago, DrmCa said:

I cannot understand how a shorter and weaker spring can keep the knob from turning any better.

Backside Pin notches probably just worn pretty bad on the backside of your Dial knob . Does not take that much pressure of the spring/pin to keep it from turning . I would just get ta new turn dial .

People man handle and force the turning of the Stitch-length Dial . It wears out the backside of the Dal . Always push down little bit on the Reverse Lever, to release pressure on that Dial spring/pin , so it turns smooth easy when changing stitch length's  .
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[DrmCa]

1 hour ago, nylonRigging said:

Always push down little bit on the Reverse Lever, to release pressure on that Dial spring/pin , so it turns smooth easy when changing stitch length's

A neat trick to remember! The problem is likely that mine is too easy to turn due to the lack of the prong on the pin.

I cannot see anything but a dark mark on my dial. Certainly no wear exists.

 

Edited November 25, 2021 by DrmCa