My wife and I have several Singer 401A machines. She uses one at home maybe 1-2 evenings per week. It’s set up for immediate use next to her Singer 301A that gets used almost every evening. However, she uses a 401A at her mending and alterations shop every day, Monday through Friday, between the hours of 9 and 5. She also tends to retail sales during those days, so she probably sews for half of the day, and the 401A is her main machine. We have three 401A machines there so that I can have at least one setup ready-to-go as a backup to the one she’s currently using. If she has a problem with a machine, she has another one green-tagged on the shelf in the back that she can swap out with to keep sewing.
We’ve struggled with the occasional bird nest under the needle plate problem for about 8 years. It just seems like it happens for no reason. We haven’t seemed to have much problem with the home machine, but the shop machines would sew along daily for months, and then suddenly have a problem. Changing needle and trying different thread are the usual first step, and sometimes those two things would be successful, and sometimes not. Usually, in either case, the machines would be swapped out to continue sewing, and I would later check the problem machine for some physical explanation of the malfunction. It may be a week or even a month before I would get around to looking into the problem machine, and I’ve never had one act up while I was test sewing it. Not ever. I do a service order each time that I fiddle with a machine to keep a service date record.
The first few years, I spent most of my time adjusting the thread clearances at the hook, mainly opening up the clearances. Some settings that I tried caused other problems I’m pretty sure, so about 3 years ago, I began setting the clearances with feeler gauges as close to what the Singer Adjusters Manual called for as I could get them. Checking the clearances later of a problem machine didn’t show any changes from the recommended settings. Then, I got to noticing that the thread-tangle problem seemed to be happening on a somewhat regular schedule once I quit experimenting. The problems are somewhat seasonal. I don’t think it’s the machine at all, but the thread. And, the same thread will work great part of the year, but then not. I think it has to do with the humidity level where the thread is located, or the amount of moisture in the thread. Our thread is on a rack, open to the air in the shop.
Now, don’t hold me to that, but I’m certainly looking into it. We’ve been in a drought here in Oklahoma for 4 years, and the machines have not been acting up much. The last few times that she’s had the thread-tangle problem, was right after we had high humidity, and weren’t using either the heater or the air conditioner, but instead taking advantage of the spring or fall air with an open shop door.
I can’t explain why the swapped-out machine can go ahead and finish sewing with the thread that was in use during the problem, unless it’s just luck or that she’s near enough to completing the task that it doesn’t occur before she’s done.
FWIW- We have had unusually hard rain here for the past couple of days (it’s been wonderful!) We got over two inches. The air in the shop is full of moisture, but the two machines that she’s had trouble with today are the Janome 3434D Serger and the Janome CoverPro 1000CP. Neither one of them wanted to sew right. She couldn’t get the tensions set good. She didn’t use the 401A much today, and it’s worked flawlessly when she did, but they all share the same thread, so we’ll see if the 401A gives her any problems in the next few days. I think humidity and thread moisture affects sewing machine performance. Anyone else notice this?
PS- We’ve been using the TnT method of upper threading, and we’re going to add Tate’s addition too.....
CD in Oklahoma