Singer 153W102 feed eccentric troubleshooting

[rlevine]

This might be an oddball question, but I'm not sure if I should worry about this, and if so, how I fix it.

I've rebuilt an early 1940's vintage Singer 153W102 needle feed cylinder arm. I've been sewing on the machine, and it stitches well on the cordura I'm feeding it.

But. When I turn the machine by hand, there's a slight resistance that coincides with the thread take-up lever reaching it's highest point. Also at that point, the head of the feed driving arm moves slightly away from the feed eccentric. Considering the shape the machine was in when I started, it's a small thing, but I don't like the turning resistance. (The gap between the feed arm and eccentric was much larger when I got the machine!) The resistance doesn't go away when I disconnect the belt or remove the needle rock frame, so it's something to do with the feed drive. One thought I had was to try moving the lower bushing for the feed arm slightly towards the needle, but I wouldn't think the position of that bushing would cause this kind of intermittent issue. 

One other observation that might be relevant is that the arm casting is very slightly rotated counterclockwise with respect to the base. It's obviously been that way for a long time, as it was repainted at some point after the arm was misaligned. 

Some pictures attached and a video linked. In the video, I pause when the thread take-up is at the top, and rock back and forth through that point.  (And the audio in the video is awful! With the camera so close to machine, it sounds like a starter motor. It's actually pretty quiet.

Thanks in advance for any suggestions.

Rick

 

 

 

[kgg]

37 minutes ago, rlevine said:

This might be an oddball question

Is the main shaft slightly buckled??? I would check with the tip of a pencil on the shaft and see if it marks only in one spot as the shaft is being rotated. If it puts a mark all the way around the shaft is good, if it only marks the shaft in one area the shaft is bent.

kgg

[rlevine]

I think that's it, @kgg. *sigh* Dial indicator says it's out by ~.008" See the video, below.

(My pencil-handling skills didn't show it up, but a mag base + cast iron work wonders.)

So what's the group wisdom on wonky shafts? A quick perusal of the usual sources doesn't come up with a replacement part, no surprise. 

If it was a drill press, I'd take the spindle to a local machine shop to true up, and they could get it to within a thou or so.

What's acceptable for a sewing machine? Will it  run for a long time, gradually making the eccentric a tad bit convex? It sews well enough.

It'll eat at me, tho. What are people's opinions about selling it? My ethical bump won't let me hide it. Do I need to just gift it to a relative I don't like?

Thanks, folks.

Rick

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[kgg]

2 hours ago, rlevine said:

My pencil-handling skills didn't show it up, but a mag base + cast iron work wonders.

Those mag base are great aren't they.

2 hours ago, rlevine said:

What's acceptable for a sewing machine? Will it  run for a long time, gradually making the eccentric a tad bit convex?

I figure you got a few choices:

i)  Strip the machine down to bare bones and reline the casing and replace the main shaft. However that may not solve the problem as other bushings / guides maybe also be worn slightly off. 

ii) Shave a bit off the part that hits / comes close to striking the other. However that will not fix the problem.

iii) Run the machine machine until it gives you problems or requires other parts. Use a synthetic oil rather then sewing machine oil for lubrication.

How long it will last who knows. I think that will depend on how fast you run the machine and how often you are going to use it. I wouldn't be in rush to replace the machine until a problem that effects the stitch appears but I would keep an eye open for a new or newer machine.

kgg

 

[rlevine]

Thanks @kgg!

Ya, there are no perfect options. I suspect it'll be impossible to find a replacement arm shaft, and the odds of the rear bushing having a matching wobble are pretty good. I didn't think to check the arm shaft and the rear bushing for issues when I had it stripped down.

The issue is only perceivable when I turn the machine by hand. Running on a motor, it sews and sounds fine. Compared to the shape it was in when I started, it's a decent machine. 

So your last suggestion is probably the best. Run it until it has a problem, and look to swap it for a better machine. (Which was my intent to begin with!)

One quick question: what did you mean by "reline the casing?" I haven't heard that before.

Thanks again!

Rick

[kgg]

1 hour ago, rlevine said:

One quick question: what did you mean by "reline the casing?" I haven't heard that before.

I am assuming the top head casing is a separate casing then the cylinder arming casing and maybe able to be moved / twisted slight to get rid of the 1mm difference between the front and rear as you noted in the photo. Otherwise it is just a slight error when the machine was cased.

kgg

[rlevine]

13 hours ago, kgg said:

I am assuming the top head casing is a separate casing then the cylinder arming casing and maybe able to be moved / twisted slight to get rid of the 1mm difference between the front and rear as you noted in the photo. Otherwise it is just a slight error when the machine was cased.

Understood, thanks. Yes, it's a separate casting, and could be moved. I'm reluctant to do that, as it would require cutting the paint to separate the pieces. The current paint is pretty old, looking at the wear patterns, so it's been running with the mis-alignment for some time.

Rick

[Quade]

Quote

Yes, it's a separate casting, and could be moved.

I've only had one industrial completely apart. A Singer 211.   There were two dowel pins and 4 bolts that held the casing together and in alignment.  

With the dowel pins, it would be pretty much impossible for them to mate incorrectly and/or go out of alignment. 

I'd look to see if you have dowel pins, if they're there or not and whether the bolts are tight.