Is this normal?
 

I have a Singer Featherweight 221. It works perfect for piecing fabric together and making garments. But I've noticed that it tends to get stuck when I have more layers with the fabric, like if I'm sewing a binding on for a quilt. Usually the needle stops, and I have to use the hand wheel to eventually get through the fabric, until it finds that it's easy to sew again. Is this normal for the Featherweight? I'd like to purchase a walking foot, but I'm wonder if it would be worth it if my machine doesn't like thicker fabric?

Remember it's only a belt-driven machine, so not quite as strong penetrating the fabrics as a gear driven motor. It's probably only happy doing your piecing, and not your thicker work.

The best penetrators would be any machine with an internal (often called "potted") motor. They have no belt and are completely gear driven. Very strong. I have a couple I could recommend: The Singer 301, 401, 500, and the Juki TL2010Q. You can hem jeans on these.

Don't forget the vintage Singer 201 and 99 15. The 301 is a great machine as it's easier to carry due to it's being lightweight. If you really plan on sewing heavier fabric and want a newer machine with many designs, go to your sewing machine dealer and tell them you need a machine to sew heavy fabrics. I got an Elnita ef72 I am happy with because it has more designs than I'll ever need and has performed well on heavy fabrics.

I can't tell you if that is normal for a Featherweight. Is the belt slipping on the motor? Check belt tension. Is the inside of the belt glossy, meaning it would be slick? Try a new belt. Are you using the proper needle for multiple layers? There are different points on needles at the sharp end, chisel, ball, "universal", etc. You want something that will be able to cut through multiple layers.

I have a FW. Mine will balk at thickness, doesn't matter what sharp needle I'm using. Every once in a while the belt will slip at first stitches. I use it for piecing at retreats. It does that perfectly.

There was someone on another board that used the FW to make a carrying case for it. Used a blanket, canvas and fabric scraps for lining. It also had webbing for the handles.

The FW motor isn't designed to sew thickness. It may burn out.

I have 2 FW's that I use regularly. While most of my work on the FW's is just piecing, I have sewn bindings on with no problem. I usually use bamboo or Quilts Dream Request batting.

Do you adjust the foot pressure when sewing heavier items?

Checking the belt
 

I want to echo what JoeJr said about the belt. I had an original belt on my mother's machine and I noticed it bogged down. I bought a generic aftermarket belt. The poor machine wouldn't even turn! The belt was too hard and stiff. I found the Featherweight Shop online was advertising "super belts" I got one of those and was amazed the difference. Their belts are soft and grip well. I have used nothing else since.
I've used my featherweight to sew binding on a quilt. About 4 layers? I will admit that my 301 works better for this though.