amykf

I inherited my grandma’s vintage Kenmore model 47 (158.470). It’s my first vintage machine and it sat in my grandpa’s garage during the 30+ years between her death and his. Despite that, it was not too dirty and not too stuck. I’m still working on cleaning and oiling and greasing, but in straight stitch mode the hand wheel is already moving beautifully, smoother than any machine I’ve ever touched including the Juki industrial at my job. In zig zag mode though it’s doing something weird that I can’t get my head around, and I’m desperate for guidance. For eleven stitches, it turns just as smoothly as in straight stitch mode. On the twelfth, it stiffens up. Then it repeats. It doesn’t matter what stitch length or width I set, it’s always a cycle of 12 stitches. I can only assume there’s some part that moves at 1/12 speed that needs cleaning and/or lubrication, but for the life of me I can’t spot it. The only thing I see moving slower than everything else is the gear under where the cams go, but that takes way more than 12 stitches to make a full rotation. I would be incredibly grateful for any pointers of where to look or what to look for. This kind of intermittent but regular problem didn’t come up in my preparatory research and Google has been no help, so I am totally stumped.

AlZilla

That is a puzzler and having never been inside of that particular machine, I'm going to be of no help.

I am going to ask that once you figure it out, you report back here so that in future Google will be of help. A picture of the offending part would be great.

Here are some fuzzy diagrams that probably aren't going to be a great deal of help:
https://www.searspartsdirect.com/mod...470-home-parts

JoeJr

Welcome to the QuiltingBoard!

I would start with the top of the machine off, no thread upper or lower, hand cycling the machine in ZZ while watching the insides turn to see if I could spot anything catching on the 12th cycle, or any cycle for that matter.

I've had to use heat to unstick parts related to ZZ, special patterns, reverse stitch, etc on a few 158 series machines. You can use a hair dryer or a heat gun with a deflector on it, because the light wire likely runs right near where you're heating. I have removed the clamps and moved the light wire also.

amykf

Thank you both for your help! I found my culprit and it’s actually pretty interesting. It was indeed in the top, right by the light cord. When I opened the machine yesterday, I was confronted with a solid metal plate where the decorative stitch cams would sit. I couldn’t figure out how to remove that plate without entirely disassembling the cam follower assembly (a frightening proposition), so I did my best to work around it. However, looking at the blurry (but still helpful) diagrams this morning, I began to develop a suspicion that I could carefully remove the plate without disassembling everything else. So I tried it and voila! On the underside I found an additional gear that translates the motion of the main upper shaft to the large gear I could see, which in turn has a bit on the top for turning the decorative stitch cams. I can’t say for sure because this gear is completely hidden when the machine is assembled, but I suspect it rotates once every 12 stitches.
So I greased it up and put the plate back and this is where it gets interesting. With the screws still out and the plate just sitting in place, everything was perfect. As soon as I tightened down the screws, the problem came back. I discovered that there is some wiggle room in how the screws go in, and the gear was catching if the positioning was not perfect. So I held the plate in place with my hand and tested by turning the hand wheel, found the right spot, and tightened down the screws - and it worked! Onward now to the next stage of the project.
I did take pictures of the top and bottom of the plate and even marked the location of the screws that hold the plate in, but I can’t figure out how to upload them.

OurWorkbench

Welcome and congratulations for getting it figured out. Thank you for reporting back on what worked.

We like pictures. In order to post pictures on Quilting Board, you will probably need to reduce or compress the picture to a file size that is smaller than 2MB. How to post images can be found at https://www.quiltingboard.com/attach...020-01-17-.pdf
Don't forget to scroll over to the far right to find and click on the "Upload" button. As shown at Standard Sewing Machine Co. Paragon

I have found that only the big red "Reply" button or "Quote" work to give me the paper clip icon to work for adding pictures.
https://www.quiltingboard.com/attach...p-location.jpg

Some additional info regarding reducing images at post #4 and images for the scroll and upload button can be found at #5 of quilt block ID?

Another way to post pictures can be found at 2021/2022, 2.5” Birthday Swap
And how to use an ipad to post pictures can be found at Uploading photos

Or simply - Make sure pictures are smaller than 2MB
Click on red "Reply" button
Click on the paper clip icon
Click browse - choose picture/s. (only 5 allowed per post)
Once they show up as being loaded, Scroll over to the right side and click on "Upload"
After the pictures show up as being attached, you can close that window and go back to the screen to finish posting your post.

Some additional notes -
The photos generally need to be reduced to less than 2MB in size. I have heard of people sending an email to themselves as it will ask if you want to reduce the size.

I have an android phone and when I tried to reply on Quilting Board while in mobile view None of the options for adding pictures was available. However, there is an option down at the bottom left of the page that is for Full Site when I tapped on "Full Site" It then looked like the way it looks on my lap top. So it would have the Red Reply and the Go Advanced options.

Do Not Preview post.

Janey - Neat people never make the exciting discoveries I do.
Not affiliated with off-site link(s)

amykf

I think I got the photos but not certain, I guess we’ll see after I submit the post! One photo shows the plate in place, with the yellow dots marking the locations of the screws. The other shows the plate removed with the gears on the underside.

quiltedsunshine

Good job as a detective and sewing machine mechanic! Not everyone has your deductive skills!

AlZilla

I'll add my thanks for reporting back. If we bury these tidbits in our brains, one day they'll be just the spark we need to solve our own 12th stitch conundrum!

Very nice work and a satisfying solution.

greaterexp

Thank you so much for taking the time to return to the post and report what you found to be the trouble. You will surely save some folks a lot of time!

JoeJr

I'm glad you figured it out, and for me that would have been a pretty gutsy deep dive into taking apart a machine.