VERY NICE work!
I was teaching a friend how to sew last night. I realized that I never explained exactly what a walking foot does or when you need one.
Basically most sewing puts two or more layers of fabric between between a presser foot and feed dogs. Feed dogs are those little serrated metal things that stick up from the bottom directly under the presser foot. Ideally they drag both layers of fabric forward so that when the needle comes down each time it's hitting a standard stitch length selected by you. Unfortunately all this can go 'orribly 'rong sir! The presser foot compresses the fabric to help get consistent stitches... but it's also easy for the presser foot to put drag on the top layer. If you sew a seam and one side looks puckered while the other side looks stretched - that's mostly a friction problem. Wool, knits of all kinds and pieces of fabric cut on the bias all love to stretch and the presser foot just makes it worse. The classic example is one where a seam starts off with plaids matching stripes perfectly... but within a foot or two the match starts to creep and by the bottom of the work, the plaid's stripes can be off by half an inch.
A walking foot is basically a presser foot with little nylon or metal downward facing feed dogs. The feed dogs are powered by an arm that goes over the screw that holds the needle into a shaft that goes up and down. With the pump action of this arm the top feed dogs move in sync with the bottom ones. This keeps both sides aligned perfectly.
A walking foot isn't necessary with a lot of fabrics, but it's always a handy tool to have in your arsenel. (You can always hand baste every single piece before you sew it - or you could hit yourself in the head with a hammer because it feels so good when you stop.)
How to know you're gonna need a walking foot:
- it's plaid and it isn't vinyl or interfaced with an iron on stabilizer
- the fabric is wool flannel plaid, with cotton flannel plaid running a close second
- The fabric is slick and shiny - satin, crepe back satin, any light weight knit including silk, rayon, nylon, etc. Any thing that easily stretches in your hand.
If you are sewing on the bias, or with one piece bias and the other on the grain, a walking foot isn't enough - you need to use stabilzer, or put in stay stitches or machine baste and ease the two layers together. I can SHOW you how to do an inset sleeve but I can't tell you how. Go to the internet I'm sure someone has a youtube tutorial.
BTW - fabric stabilizers - learn about them. They are essential for machine embroidery but can do SO much more. I've gone quite mad for them and no - I'm not glue sniffing!