Feeding the animal
With this page we'd like to discuss and show some features of the feed system of sewing machines and give you a way to get some idea if your machine is working correctly. Adjustments to the feed system are rather complicated and there's really no way you can make them yourself, but you can get an idea of whether of not yours has a problem you need to have checked out.
The major symptom of an ill feed system is that the fabric wants to pull to one side. Or, it doesn't want to feed at all. Sometimes it feeds so slowly that the stitches are irregular. A satin stitch is a good indication: bunched up, erratic.
The feed system is an intricate part of the machine and it has to be correctly timed. Also, the height of the feed dogs has to be precise. Adjusting both timing and height requires things like pipe wrenches, explosives, and sledge hammers so you don't wont to get involved with that. But you can do some field testing on these. Let's take a look at the feed dog area.
Remove the needle plate--a common practice that you should do frequently for cleaning. and you'll see something like this: exposed fee dogs
The arrows are pointing to a couple of grooves within them that collect a major amount of lint which compacts into really thick stacks of feltish material. We frequently have to take a needle to pry them out. Perhaps you will to. These compact because this area of the fee dogs push up against the needle plate as you use the machine, getting bigger all the time. When you get a major collection, you'll not be able to blow these out: you'll probably have to do what we do and use a needle to pry them out.This can affect the range of motion your feed dogs have, resulting in less than adequate feed dog height. Clean them out or get someone to do it for you. Oiling this area is not advised. The extra oil will help collect more "stuff" and there's nothing here that needs oil anyway.If your machine does directional stitching then the feed dogs are what move the fabric. Not the correct height? Then then you'll find the directions are off or not adequate.
Let's talk a bit about testing for height:
The following is a quickie field test that you can do but
to do it correctly your technician will need to use some specific gauges.
Beli
eve
it or not but a well trained Bernina technician spends quite a bit of time in
training using specific tools to get this correctly diagnosed. If
adjustments are required, then that's another matter altogether.
But as a field test you can do this to get some idea if your machine's feed dogs are about right.
Set your stitch to regular straight stitch. Turn the handwheel until the dogs are as high as they will go. What we've done is to fold a letter size sheet of paper in half and placed it against them as shown. Basically, the dogs should be about the same height as the fold in the paper. We've worked on machines that have the dogs more than two and sometimes three times the height and that's not a good thing.
Of course, we are showing Berninas in our pictures and your machine might be a bit different so although we work on about every type of machine made, keep that in mind when you do this. But for Berninas this is a good way to test at home.
If you take your Bernina to a Bernina dealer for servicing, this will be done automatically for you.
