miriam

I hope that pop was not a gear breaking.

Jassinc6

You had me scared! I just plugged her in and she runs nicely and sounds very good. How would I know if a gear had broken?

Rodney

If it's running smoothly you're probably ok. The pop could have been caused by any number of things like a gear slipping as well. If the gears are plastic, they may have enough give to let them ride over each other instead of staying meshed together like they are supposed to. Try sewing with it. That will tell the true story. If the wrong part slipped you may need to re-adjust it. I've been lucky with my machines so far. All they've needed was a little oil to run.

The backwards photo had me going too. I've never seen a left handed machine and would have bought it just for that if it was true.
Rodney

miriam

If it spins but no needle going up and down. Think gear that doesn't turn the next gear.

Jassinc6

The machine did not come with a bobbin. I tried several and at first I got one to wind on the bobbin winder but it wasn't winding correctly. Then the bobbin winder completely stopped spinning. I took a wound bobbin from my 401 and put it in the bobbin case, threaded the machine and after adjusting the tension, got it to sew both a good straight stitch and a nice zig-zag stitch. My concerns now: is the 401 bobbin the correct one to use on this machine and what to do about the bobbin winder. All help will be much appreciated.

mjhaess

Wow..What a beautiful machine...Go back to the thrift store and see if they still have it.

miriam

If it is a drop in bobbin and a class 66 fits you should be good. If it goes in a bobbin case you need a class 15. Touch and Sew machines need special bobbins.

manicmike

The gears in question are the hook timing gears. If they break, your machine's bobbin stops moving, or skips a few cogs causing the timing to go off and the needle will stop picking up the thread, produce a horrible stitch or (at worst) punch a hole through the bobbin case (if it has one).
At this point in time the gears on these machines are nearly all broken, or are about to. If I were intending to keep such a machine, I'd have a look and see if the gears have already been replaced. If not, it's not a difficult job and they're not expensive or rare. If they've already been done you should be OK for another 40 or so years.
The instructions for replacing the gears and resetting the hook timing are easily found with Google.
They break due to age. The plastic becomes very brittle over time and eventually breaks off.
My daughter's machine had the original plastic gears and they broke after about 6 months. Not a big deal but inconvenient. If I'd known they would have been replaced as preventative maintenance.
The bobbin problem is easily fixed too: Remove the top cover and look underneath the winder post. There should be a spring mechanism and a small rubber ring that will touch the hand wheel when the bobbin winder is active. Either the rubber has perished (get a new one) or it needs to be adjusted.

Jassinc6

I got the bobbin to wind on the winder. I will share what I found even though many of you would have already known this. I did not because I have never owned or operated a machine that the smallest hole on a bobbin was for anything other than starting your bobbin thread (at least that's what I use it for). The Singer 615U takes the Class 66 bobbin that has 3 large holes and 1 small hole. The small hole matches up to a tiny peg on the base of the bobbin winder and when I matched them up and snapped it down a bit the bobbin wound perfectly with no adjustments needed to anything. Feel relieved but a little "dumb" for not trying that sooner. Just hope that my little bobbin saga will help someone else down the road if they run into this problem. Thanks for everyone who graciously tried to help me. You all encouraged me to keep going and now I have this really nice machine that sews beautifully and will also wind a bobbin.

Rodney

I just went thru the same thing on our machines. Both use a Class 66 bobbin. Until a few weeks ago I'd never used a sewing machine and was pretty clueless about them. Still clueless, just not as bad now.
I bought Singer bobbins at Walmart. There seems to be a quality control issue with the metal ones in the 4 packs. Some are larger than others in the packs. I ended up throwing a few out because they didn't fit in our machines. I think out of 8 total I was able to use 5 of them. At 4/$1 it's not a huge deal, just annoying.
Rodney