random messed up stiches?

[Ser Niall]

Hey everyone.  I'm currently teaching myself to sew, and I think I did pretty good for my first weekend.  I successfully took the machine apart to clean and oil it (purchased used on craigslist for very cheap, needed some TLC), wound a bobbin, threaded the machine, and sewed some practice stitches.

My question is general to sewing, I hope it's appropriate to post  here as it's not garb-specific.  I've practiced some straight stiches, as well as the zig-zag pattern.  I'm just trying to get everything nice and straight before I go ahead and try a full project with patterns.  Everything stiches up nicely, but every once in a while I get something that looks like the picture below on the bottom of the fabric.  Any clue as to why this happens, machine malfunction or user error?  I've tried adjusting the thread tension a bit, but nothing seemed to prevent it.  It doesn't happen all the time, it seems like it's random.



thanks in advance!

[Kate XXXXXX]

That looks like a typical upper thread tension problem.  Try this:

Take all thread off the machine.
THOROUGHLY clean out the bobbin case area, checking for burrs and scratches.  Remove all dust bunnies!  Oil the oiling points with a single drop of SEWING MACHINE OIL on each...
Clean between the tension disks with a soft, lint-free cloth: I recommend a microfiber lens cloth.

Put a new needle into the machine: size 80.  Make sure it is in the correct way round.

Reinsert the bobbin, making sure that it has been wound nicely and evenly, with no loops, wobbles, or more thread at the top or bottom, and is the correct way round.  Ensure that the bobbin thread is correctly seated behind the flat leaf spring on the bobbin case, as this puts the correct tension on the bobbin thread.

Thread up with standard COTTON thread...  Make sure that the thread follows the thread path correctly, through all the guides and the take-up lever, and through the needle correctly: most modern machines thread from front to back, but some older ones (usually straight stitch rather than swing needle machines) will thread left to right or right to left...  Check in the manual.

Set you stitch length to about 2.5mm/the middle of the stitch length range.

Set your upper thread tension to Normal/the middle of the tension range.

Sew a seam through two layers of quilting weight/calico plain cloth.

If this looping on the bottom side of the stitching still occurs, try stitching again with the bobbin case cover open: go slowly and try to see where the thread is catching.  You may have a small burr on part of the shuttle hook or shuttle mechanism, and this will need a repair or replacement part.

If it stops happening, then the looping is probably cause by either miss-threading of the machine or an incompatibility between the thread type, the needle size, and the cloth, a burr on the needle, or some other minor problem eliminated by the clean-up.     90% of this sort of looping on the bottom of the work is caused by a user-induced error.

If you still have a problem, then take the machine in for a service, and take a sample of the looping in for the engineer.  It'll give them a good pointer to what is going wrong.

[Anna Iram]

Gonna throw in one more thing. Be sure the pressure foot is up when you thread. Threading with the foot down will cause bunching. A common mistake and one I experienced and learned from. Hope you find your problem soon.

[Butch]

Sometimes I had that happen when my stitch length was too short.  Also, I've had that happen when the thread slipped off the moving rod on the front (the piece that pulls the thread up.)  Good luck!

[Baroness de Vale]

I had this happen with my older Singer and it drove me crazy. I tried everything that could be done at home. One of the last things I did was remove the part of the bobbin case that actually holds the bobbin and look at it very closely. I realized it was worn out(darn plastic). One quick fix later and I still use that machine. This was a case where taking it in for service would have saved me weeks of tearing my hair out.

[DonaCatalina]

Make sure that you have the correct bobbins for the machine you are using also. Bobbins that are too small or too large will cause random bunching also.

[Ser Niall]

Giving the bobbin area another cleaning, this time with some compressed air, and changing out the needle seems to have corrected the issue.  I was using the needles that came with the machine, and who knows how old they were.  I haven't seen that bunching occur since, so I'm crossing my fingers.

Thanks for the tips, if I see this happen again I have a resource to come back to for information!

[raevyncait]

Also, in my experience, if your machine isn't somewhere that you can leave it up all the time, check tensions, etc. before you use it after moving/setting up, even just inside the house.

[Kate XXXXXX]

Giving the bobbin area another cleaning, this time with some compressed air, and changing out the needle seems to have corrected the issue.  I was using the needles that came with the machine, and who knows how old they were.  I haven't seen that bunching occur since, so I'm crossing my fingers.

Thanks for the tips, if I see this happen again I have a resource to come back to for information!

I advise against compressed air.  You are far better hoovering it out with one of those sets you get for hoovering computers (not the mini vac things, the attachments of a proper hoover).  Compressed air can blow dust and broken needle schrapnel further into the works of a machine, and can chill metal parts, causing condensation, which is all sorts of not good for the insides of the machine.

Compressed air is used in industrial machines in a factory setting, where the machine covers are taken off before blowing the air through the machine rather than into it.

[Ser Niall]

Giving the bobbin area another cleaning, this time with some compressed air, and changing out the needle seems to have corrected the issue.  I was using the needles that came with the machine, and who knows how old they were.  I haven't seen that bunching occur since, so I'm crossing my fingers.

Thanks for the tips, if I see this happen again I have a resource to come back to for information!

I advise against compressed air.  You are far better hoovering it out with one of those sets you get for hoovering computers (not the mini vac things, the attachments of a proper hoover).  Compressed air can blow dust and broken needle schrapnel further into the works of a machine, and can chill metal parts, causing condensation, which is all sorts of not good for the insides of the machine.

Compressed air is used in industrial machines in a factory setting, where the machine covers are taken off before blowing the air through the machine rather than into it.

Thanks for the warning, I shall not blow air into my machine again.  Being a computer nerd, I'm used to cleaning everything electronic and mechanical with compressed air

I'm hoping to get started on my first "real" project sometime this week.

[gem]

One great suggestion I heard on Pattern Review was to use a turkey baster to gently puff lint out of your machine with *dry* air. It's especially good for sergers, which accumulate fuzz like it's going out of fashion.

[C Dragonworks]

Using air is OK as long as you OIL all the metal parts well... I prefer it in the bobbin area.... and if you take off the top cover on most machines and blow down it will get out all sorts of odd things living in the machines.... I collect and restore OLD machines.... I Treadles from the 1800s and my most modern is one we bought new.... Don't even ask me how many machines I have I honestly can't tell you anymore... but I use brake cleaner to get the old gook off the working in the all metal beasts(being careful NOT to get it on paint) and then oil with high quality machine oil... check your bobbin tension... on the bobbin case there is a small screw that adjusts it...pull gently it should come out with a bit of extra pull not super hard but not sloppy easy either... If this is too tight it will often cause the looping you saw... and you may simply need to take the upper tension knob out and clean it...if you are not sure of this take it to a shop!