Singer 31-15 Mechanical Issues

[ponygirl]

This is a continuation, and a change, of my thread below... I wasn't sure of how to change the title, so I started a new one here. So it seems the bobbin isn't the problem. It was suggested below that the needle was hitting the bobbin case, so I took it apart and that doesn't seem to be the case.

Now the flywheel is spinning (with or without the bobbin case and bobbin in place) and the machine is not working properly. Sometimes it will work and sometimes the fly wheel will just spin and the needle won't function. Sometimes when it does work, the motion is very jerky and erratic, sometimes it works smooth. Like I said in my other post, the machine was working fine the first couple days we had it, then it decided to go postal on us...

I have posted a video on YouTube,

I'm sure it does a better explanation than I. I am mechanically illiterate, so any guesses as to what's going on would be great. I'd like to tweak with it and see if I can avoid the long drive to the repair shop. Thanks in advance.

[kevinhopkins]

Hi...As much as I hate to say it, I think a trip to the repair place is in order. As to the bobbin falling out, it's not an issue. There are several things that you need to have checked. First of all, I think your drive belt is a bit loose. (altho that shouldn't affect your sewing) It's quite possible that your shuttle is loose. The bobbin fits into a shuttle case. THe shuttle case attaches to the drive rod and is tightened by means of a screw. (possibly 2...I can't remember for sure) But if that shuttle is loose, it will do exactly what your machine is doing. It also seems like you might have a bit of thread somewhere in either the bobbin case, or between it and the shuttle, or somewhere in that mechanism. It can also contribute to what you're experiencing. Those old 31-15 machines were a standard of the industry, and usually can be kept running fairly easily. And before I forget it, make sure that the hand wheel is tightened on the shaft also. If you're a bit mechanically inclined, just tilt the head back, and while its tilted back, just start turning the wheel, and watch and listen. when that shaft turns, everything should turn. Sorry I can't be more help! Maybe someone can be a little clearer than I.... Don't be too frustrated!

Kevin Hopkins

[TwinOaks]

Take this advice with a salt block....not a grain....a block.

I have a 66, and in the center of the flywheel, there's a knob. That knob is loosened to use the bobbin winding accessory. I have no idea ff the 31 has a similar attachment method for the flywheel, but it'd be worth checking. When loosened, it allows the machine to run without moving any of the other parts -needle, hook, etc.

No info on the bobbin/shuttle other than my Viking 6440 has a similar bobbin and if inverted, it too will fall out. One of those 'gotta be careful' things, I suppose.

Edited May 20, 2009 by TwinOaks

[Luke Hatley]

TAKE IT TO THE SEWING MACHINE MECHANIC AND YOUR TROUBLES WILL BE OVER.....

I'VE HAD TO DO IT A FEW TIMES. AND NOW MY 31-15 IS NEAR PERFECT.........

...... and while you are there ASK A LOT OF QUESTIONS,,,,,,,,,

Edited May 20, 2009 by Luke Hatley

[cdthayer]

...sometimes the fly wheel will just spin and the needle won't function. Sometimes it does work... machine was working fine the first couple days we had it, then it decided to go postal on us...

Some of the older Singer 31-15 machines that were originally set up for treadle operation did have the "stop motion device" on them that TwinOaks referred to in an earlier post. It's a threaded knob in the center of the handwheel that allowed the user to treadle the bobbin winder without turning the machine mechanism. Not all 31-15s have it, and I can't see the end of the handwheel of your machine to see if it has it. The way that your machine is acting, and looking at the size of your handwheel, it may have the stop motion knob on it. The fix would be to simply tighten the knob (right-hand thread) more with your hand. The fact that the machine sewed fine for a while and then started acting up could just mean that the old debris on the shaft under the handwheel finally broke loose. Download the User Manual for the 31K from Singer at http://parts.singerco.com/IPinstManuals/31K.pdf to read about using a stop motion device (and see what it looks like - on page 4), or a Parts Chart for the 31-15 at http://parts.singerco.com/IPpartCharts/31-15.pdf (page 4).

Not all BCs (bobbin cases) had the "latch" built into them that hold the bobbin in when the BC is tipped, especially the older ones. Runaway bobbins were probably what spurred the development of the latch, but I don't know that as a fact. It's basically just a tiny extension of the release lever that pivots in to jam against the edge of the bobbin.

The BC may not be latching securely onto the hook shaft due to wear on both the latch and the pin, or simply just "not holding your mouth right". Some BCs can be a little cantankerous about being inserted "just so".

CD

[cdthayer]

The BC may not be latching securely onto the hook shaft due to wear on both the latch and the pin, or simply just "not holding your mouth right". Some BCs can be a little cantankerous about being inserted "just so".

Or, it might not be the correct BC. Those get lost often, and someone may have put one in that was almost the same, but not quite. Compare yours to the one in the parts manual (page 6), although the photo may not give you enough detail, and see if anything catches your attention as being different...

CD

[torrbuidhe]

Do you have a friend or relative who is mechanically compotent? I find sewing machines quite easy to work with.

It does seem like you have a stop motion flywheel, I'm not familiar with these but there may be dirt or wear in the mechanism.

I think you should get a new bobbin case, they're not expensive. The bobbin fits in the bobbin case which is placed in the shuttle. The latch holds it on the post in the shuttle. The bobbin case stays stationary while the shuttle oscillates in the shuttle race - no screws involved. You could always get a new shuttle as well in case the post has wear on it - these are also cheap.

You should also join this forum - http://www.needlebar.org - it's for people who collect old sewing machines. You should be able to get plenty of help there.

Neil.

[ponygirl]

Thanks all for the responses and advice. I'm going to take some of those pointers in the morning and see if we can't get her working again. I'll let ya know how it goes! Thanks again.

[ponygirl]

Hey all! Turns out the flywheel was loose! I feel so silly now, it's stitching perfect now. Thanks so much for that suggestion, if we had not checked that, we would've went to the shop. However, the knob in the center in the flywheel doesn't want to STAY tightened. Any ideas how to keep it from loosening?

[Tkleather1]

Blue Loctite. it will hold the threads but if you ever need to take it apart again it will break loose and not damage threads like the red loctite can.

[cdthayer]

Hey all! Turns out the flywheel was loose! I feel so silly now, it's stitching perfect now. Thanks so much for that suggestion, if we had not checked that, we would've went to the shop. However, the knob in the center in the flywheel doesn't want to STAY tightened. Any ideas how to keep it from loosening?

Years of tightening and loosening the clutch to wind bobbins, if oil wasn't applied to the threads every once in a while, would wear the threads down to where they fit a little "sloppy" and back off with use. An old remedy was to wrap sewing thread around the threads to gently "jam" the threads. Put some oil on the threads and your added "thread wrap" to help slow down additional wear. Plumber's Teflon thread tape works on the same principal, and provides both the "jam" plus the lubrication.

CD

[ponygirl]

will do...thanks guys! I'm so excited to make my first pair of chinks