Singer 404 problem
 

I bought a Singer 404 last year to work on some heavy duck cloth making covers for airplane. It has always jammed up in the bobbin area. I had it in for repair/check to see what was wrong with it and the repairman couldn't find anything wrong. But as soon as I got it home and tried to do piecing with it, it jammed again. I think he was putting the "pedal to the medal" and doing continuous stitching but when I start and stop stitching as one would do in piecing or attaching binding, the machine jams in the bobbin. Could I have a wrong size bobbin in the machine? How can you distinguish between the metal bobbins and does anyone know the correct bobbin for the 404? Any advice appreciated.

I have a 401, and it take a 66 type bobbin. The only time mine jams is if I forget to trim off that thread "tail" that you use to put through the hole when you're filling the bobbin.

Sorry I'm not more help.

bkay

How much foot pressure are you using? The foot may be letting the cloth move around too much.

Only other thing I can think of is to to try and find a needleplate that only has a small hole for a straight stitch.

It does use a 66 class bobbin and the ones you buy now are from china and are junk. If you buy ten you will throw
three away. Put each bobbin down in the bobbin case and see that it rotates freely and you can wiggle it around.
The bad ones will be snug or tight. The plastic bobbins seem to be better and stay loose. If you have a bad bobbin
then every time you put that bobbin back into the machine it will jam. It is best to check your machine with a known
good antique bobbin. Then keep that one just for testing when you suspect possible bobbin problems. Make sure the
exact same type of thread is being used on top and in the bobbin. If you don't you will have tension problems. Some
machines also don't like thick thread and you will need a big needle.

What do you mean by Jam? Is it the thread that is jamming or the needle won’t pierce the fabric or what? If it is the thread that is jamming it could be you are starting with the needle not all the way through the rotation. It will jam every single time. The needle has to be up and the bobbin thread has to clear the hole. If the needle wont pierce you may need a larger needle. The largest would be an 18. These machines are really not all that heavy duty. If you do have the wrong bobbin it will do funny things. A class 66 doesn’t have a lot of holes. It is curved. You can buy them in a lot of places. Some are good and some not so good.

Well I tried tracking down the problem again on my 404. The thread is still jamming up under the needle plate. It Is a single hole needle plate not a wide hole as it would be if the machine zigzagged. it will sew along fine for a bit but if I stop sewing to readjust or something and start again, it will jam underneath and stop sewing. The repairman said he couldn’t find anything wrong with it but I think he sews a few straight seams without stopping and it seems to sew fine. Any suggestions? I would really like to be able to use this machine for piecing. Tried removing the bobbin and case to see if there could be a thread caught under there but see nothing. Can’t see anything from the bottom of the machine either. I think we got taken on this machine,

I'd take it back to your repair guy and have him test it like you're sewing when you're having a problem, or you can try a different repair person, but personally, I'd have the first guy find/fix the problem, because I assume you paid him the first time, and he shouldn't pay him the second time.

This is a very solid model, and relatively simple since it's a straight stitcher. If there's any problem I would take out the needle plate, bobbin and bobbin case, double and tripple check parts down there, scrape every groove, corner, opening, passage, etc. with a tooth pick to check if there's any lint or grime stuck some where. That's the only tricky thing about this model, lint gets stuck in hard to reach places in the bobbin - feed dog area, and it almost always improves with that extra careful inspection and cleaning.

Another trick is to be a bit persitent; take the machine in regular use, perservere, go through all the maintanance steps and check points you can think of and you will get to the problem spot. Make sure thread doesn't get dragged down on the first few stitches of a seam or when you restart stitching after the thread has been cut. That will cause jamming. I assume you know all of this, but I swear, it's often a basic issues casing these problems.

The 404 is a wonderful machine.
When you bring it back to the technician, bring along a two layer narrow strip of your canvas, that you have done test stitching on to show him the problem. In fact, leave the last jam under the needle. Make sure there is enough canvas length for him to test sew with.
If you are making an airplane cover, I can imagine you are working with large pieces and quite a lot of weight and drag against the needle. It must be difficult to not "push" the fabric past the needle. Make sure your work is well supported. The feed dogs should be able to feed the fabric, your hands are there just to guide it.
I would also imagine that working with canvas you may need to change the needle more frequently. Are you using a sharp tip needle, vs. universal or ball-point?

how does it sew with standard weight fabric?