Is a walking foot necessary?
Do you have to use a walking foot? I cannot find one that will fit my machine because it is so old.
I'll break your question into two parts, as both are important...
The machine you quilt with is called a 'sewing machine'. It's intended purpose is to sew stitches to create garments.
When we piece with it, we are merely 'sewing' two pieces of fabric together, the same as when we sew the front to the back of a bodice. Having feed dogs underneath the two pieces of fabric is enough to guide them through the machine.
So what if the fabric shifts a little bit during garment construction. We've pinned along the seam line
to hold things pretty much in place. So no problem!
Quilters need a 'quilting-machine'...
Now when we quilters decide to use that same 'sewing machine' for 'quilting'...and I mean quilting--stitching the three layers of the quilt sandwich together--we need to make some adjustments to the machine to make it 'quilting-ready'
If we'll be stitching in the ditch or a fairly straight lines of quilting, the first addition is a walking foot
A walking foot is needed because...
...it adds a set of feed dogs to the top of what your quilting. That's all. But it's so much, too.
Think about it.
Your pieced quilt top is full of seams. That means lots of bulk.
Now add a batting. That's a lot more bulk than a simple front and back bodice to stitch together.
And remember, as you pin basted your quilt sandwich you avoided pinning in the seam lines. We quilters are smart. Why put pins in that you'll remove within a couple minutes of starting to quilt?
However, that means our quilting lines aren't stabilized by pins.
The walking foot helps us turn our sewing machine into a quilting machine.
The feed dogs work together, as one, grabbing and pulling the layers of your quilt through the machine.
Without a walking foot, the standard presser foot would be pushing your quilt's top layer towards you because of the bulk. You'd end up a rumpled quilt after an exasperating quilting session. To learn more about how a walking foot works, see Quilting Foot: A Beginning Quilter's Best Friend
Maybe a darning foot...
If you wish to avoid using a walking foot altogether, then your alternative quilting foot is a darning or hopping foot. With this foot, the you must drop your sewing machine's feed dogs. You
are in charge of moving the quilt sandwich through your sewing machine and creating the stitch length.
I use my darning foot almost exclusively these days. I find that even stitch in the ditch is easier and creates less tension in my body while I quilt. It does take practice to gain this skill.
A walking foot will have you quilting your quilts immediately. Free motion quilting takes a bit more practice. To learn more, see Choose the Best Darning Foot for your Free Motion Quilting
Find a walking foot for an older machine...
It is possible that a walking foot DOES exist for your sewing machine.
Contact the manufacturer or local dealer of your sewing machine. If there is no local dealer, then manufacturers do have websites, just use their contact form to ask.
If that fails...
Then you'll need to identify if your machine is a high, low or slant shank machine. You'll need that to see if there is a generic foot that fits.
To determine which shank you have, see this Q&A for finding a walking foot for an antique Singer sewing machine
Once you've determined what kind of shank you have, then go to a website like www.clotilde.com to see if there's a generic walking foot that will work on your machine.
I hope this information has helped you. Excellent question. We don't always remember we are really pushing our sewing machines when we quilt on them!