Some of you may remember back a few months ago when I wrote about the program we had at quilt guild about how a machine actually makes a stitch, and how using different fabric, thread, and needles work. If you don't remember, you can check it out here. Well, the gentleman who gave that presentation, Al Hunt, was at our day chapter of guild last week, and he had more important information to share.
Just to "introduce" him, Al has been repairing and servicing machines for 30 years. He shared that he has serviced 31,000 machines of every possible type, so he knows what he is talking about. Further, he teaches other technicians at Bernina University and also wrote the book that Bernina dealers have about servicing other makes of machines. He is also an excellent, interesting speaker! I'm telling you ladies, if something happens to your husband, this is the man you want to, er, "hook up" with, ha ha (Sorry about the pun.) (If you didn't get it, the hook is the part of your sewing machine that does all the work.)
So today's topic was about cleaning and oiling your machine. The frequency of these two tasks depends upon the frequency that you sew. However, if it has been more than a few weeks since you cleaned (and you sew every day) then you probably should do so. You should actually oil more frequently than you clean, maybe every few days or every 8 hours of machine use. (I'm already in trouble!) I personally have a routine where I wind about 6-7 bobbins and when they are empty, I clean and oil. After hearing this talk, though, I'm going to try to oil more often.
With all the machines out there, when you get down to mechanics, there are only three types of hook mechanisms. He gave us guidelines for each, and while it is going to make this a long post, I think it is valuable informaion.
First off, you should use a nylon brush made for cleaning machines! Don't use a natural bristle brush like a makeup brush, as it isn't as effective at removing the debris. (Another thing that I'm guilty of--I use a dash brush for a car.)
The first type of bobbin mechanism is called the rotary hook. This is the style that every featherweight, long arm, and older Pfaffs (prior to about 10 years ago) are. To clean this style you should:
1. Remove the throat plate
2. Remove the bobbin case
3. Brush out all the debris from the feed dogs and case.
He said that to really get the machine clean, you should put a drop of oil on the brush. (Just as you would use a little furniture polish on a papertowel to dust your furniture) The oil is not just a lubricant, but also a cleaner. The technique with the brush is not to "paint" but to jab and flip. You can't hurt anything down in the area, so really work at it. When the brush gets full of dirt and lint, clean it with some more drops of oil and a paper towel and keep at the cleaning until the machine is free of debris. Also, it isn't good to use the can of air to blow the stuff out! It has moisture in it and can cause rust.
When it is clean, the best technique for oiling is just to place a drop of oil on the tip of your small screwdriver and then touch the screwdriver to the hook where the silver basket and black gib meet.
The next type of bobbin is the the CB (Central Bobbin). This type is found on most Berninas and all industrial types. It consists of the bobbin case that comes out after you release a lever. For this you shoud:
1. remove the throat plate
2. unlatch the race cover so it falls open
3. remove the bobbin case and the hook
4. With the brush (oily) do the jab and flip method of cleaning as above. You want to make sure that there isn't any debris left, especially in the groove where the hook moves. That groove is called the "race" and you should consider it to be like a race track. If any lint is in it, the effect is the same as if you have a speed bump on the racetrack.
5. Put everything back together. A trick to make it easier is to tip the machine back slightly, so it all stays in place until you lock it back into place.
6. Using your screwdriver tip, apply a drop of oil to the race (this can be done with the cover open or closed) Again, just the one drop is enough.
The final type of mechanism is the Drop-in bobbin and case. This is common to some Kenmores, some Janomes, and usually the inexpensive machines. The throatplate is opened and the bobbin is laying in the case on its side. For this type you really need to read your manual. Most of these bobbin cases are plastic, so they should not be oiled!!!!
To clean the drop-in, use the brush but without oil! Really get in around the edges. A good tip is to think of the inside of your washing machine and how socks will get stuck on the sides. The lint will get stuck in the bobbin case the same way.
Now that you are keeping your machine cleaned and oiled, you should just need the machine serviced about once a year. There are exceptions, but Al said that a year is good for 99% of people.
He concluded with some tips about how to avoid some problems.
1. Most people don't change the needle enough. To get some perspective on this, here is some figures. The typical machine makes a stitch 15 times a second. In 2 hours it will stitch 100,000 stitches. Those 100,000 stitches would go for 230 yards--over two football fields long! But if you read my other post that I linked above, you know that when a machine stitches, the hook grabs several inches of thread and pulls it through and then back out again. If you stitch 100,000 stitches, you will only use 230 yards of thread, BUT the amount of thread that is pulled back and forth through the machine actually totals out to be 11.5 MILES! All that is going back and forth through the eye of the needle, polishing the hole and possibly changing it or making a spur--and that can be why the thread fails (breaks.) So, a good rule of thumb it to change the needle every two hours of use. (Again I realize I'm not doing that enough.)
The next two tips are mostly for novices, but still helpful.
2. Make sure your machine is threaded correctly. Have you noticed that once you get experienced with threading your machine, you sort of automatically make sure that the pressure foot is lifted? The reason for this is that when the pressure foot is up, the tension disks loosen a bit, making it easier to thread. If you try to run the thread through with the foot down, the thread won't want to go where is should in the tension disks. (I never knew that!) Also, if you sew and get all those loops of thread underneath, the problem is with the top thread, not the bobbin. Check the threading--there is probably a problem with it.
3. Have you ever started to sew and the machine sort of grinds a bit and then you get that lump/bird's nest of thread underneath? This is caused by the lever not being up as high as it can go when you first start sewing. The new, computerized machines automattically stop it in the right position, but if you don't have that feature, this is something to pay attention to. If you start out sewing with the lever down, the machine is going to lift the lever and it will unthread your machine or will pull 2-3 inches of thread down into the hook when it isn't needed yet, and this tangles up and makes that bird's nest knot.
I hope you find this information to be valuable! I found it to be fascinating and worthwhile to share.
Have a great day!