Last December I was given a badly rusted and frozen up Singer 99K. I named him Rusty. The machine was complete with bobbin (filled), needle, needle plate, slide plate, and the rest of the parts connected to the head. Only the motor, light, wiring, foot controller and case were missing.
The machine had been in a flood, then sat out on the back of a truck in the rain.
At first I was going to part the machine out. I pulled a number of parts off to put on other Singers that needed them. Only to realize that each time I'd make a Sew-Classic order I'd order the parts I pulled off Rusty, put them on the other machines and put Rust's parts back in his box.
So I decided to make Rusty a project. It was my goal to get him freed up and running, replacing only the parts that absolutely needed replaced.
Getting all the parts freed up took a lot of Liquid Wrench, and other penetrating oils but gradually he came loose. First the main shaft, then the bottom. The biggest problem was the big arm that connects the oscillating hook to the other parts. It was rusted tight to the bolt. That didn't free up until I finally got it disassembled.
As I got him freed up I pulled off most of the bottom parts cleaning each one then oiling it as I went.
Finally down to the bobbin drive I tried to get the bobbin carrier out of the machine, but it was rusted enough that I couldn't get it out of the hook. I eventually got it out, but broke the ring on the hook in doing it.
Fully apart I finished cleaning all the parts that were off. Then made my first parts order.
I ordered the thread take up lever assembly, oscillating hook, and bought a feed dog screw from the LSMG.
About a month ago I began to reassemble the machine. A kerosene bath to flush out as much of the remaining rust as possible first, then the bottom end went in first. No problems there, just assemble it.
Then all the parts went into the left end. Needle rod, presser foot shaft, lever, and tension release parts, thread TU lever assembly, and finally the top tension itself. I used the TFSR instructions to do the tension.
Once together I set the needle to hook timing and adjusted the feed dogs.
Then overjoyed that my old rusted machine was together and would soon be sewing I found a full bobbin, grabbed a roll of thread and some scraps and threaded him up.
All the joy was dashed when all I could get was very bad birds nests and broken top thread. During the entire time I spent attempting to diagnose the problems they manifested themselves under the needle plate and around the bobbin carrier. The thread was binding so bad you could actually see the tension it was under as went around the bobbin.
I tried everything I knew, then contacted Miriam to pick her brain. For a couple weeks off an on we worked on Rusty. I'd tell her what I did, she'd make suggestions, I'd do them then report back.
Finally at our wits end, we'd done everything to find the problem except rearrange the molecular structure of the machine. I replaced the bobbin carrier as the old one is pitted. (Works good in other machines though) I also replaced the bobbin carrier latch, as it was severely pitted. Then finally the two top tension disks. Same reason. Nothing we did changed anything.
I was down to trying some parts off of Lady Godiva, my other 99k that does work. I was in the process of putting Godiva's needle plate in Rusty when I noticed something different between the two.
The thread TU lever on Godiva was sitting higher than Rusty's. I turned the hand wheels to make sure both levers were as high as they'd go. Rusty's was lower.
I was concerned that I'd gotten the wrong parts, but all the serial numbers matched. So I had to figure out what I did wrong when I put the assembly in.
I then set the counter weights on the left end of the shaft so that the needle bar, and it's connecting arm were straight and compared how all the other parts were arranged. In Rusty the little offset part with the left hand thread that the thread TU lever is connected to and is connected to the counter weight was turned different.
I loosened the screw in the counter weight and rotated the offset connector so that Rusty's TU lever matched Godiva's. Then spun them both a couple times to see what happened. I had to do a couple of readjustments to get Rusty's to match, but I got it.
Then pulled Godiva's needle plate out and put Rusty's back in, threaded him up, grabbed some scraps and took a deep breath ............. ( had put the spoked hand wheel on to make it easier to hand crank him) ........
put my finger in the wheel and started to turn it.
No gunching and gritching ....... maybe?
A couple inches of sewing and no broken thread ......... maybe??
Then a lot of inches of sewing with no broken thread .............. Maybe???
Finally after about 18" of sewing I stopped turning the machine, turned the scraps over and looked at the bobbin thread .......................... then did a little happy dance.
We were sewing. Nice little evenly formed stitches on both sides, no birds nests, no jams, no broken threads, just stitches. He even does a nice looking back tack too.
So, the entire problem wasn't a tension problem although it acted like it. It was a timing problem. The thread take up lever wasn't in the right place at the right time with the thread. It couldn't pull the thread up and out of the bobbin area at the end of it's up stroke. So everything bound up.
This morning I put the regular hand wheel back on then put a motor on and that machine runs like a race car. The only thing is I don't have a case or even a base so he want's to vibrate all over the bench top.
I have some fine tune adjustments to do, but Rusty is finally sewing.
Now, for those that want pics, I'm sorry but I don't really have any to post. Most of the befores were lost when the old computer died earlier this year. What I do have is mostly to use for diagnosis. I'll get a few of him sewing and see what else I can find in a bit.