After taking a class with Leah Day on Craftsy, I learned that dropping feed dogs is not necessary and that leaving them up can help the tension issues. I have a drop in bobbin and I gave it a try - it worked! I don't have eyelashing and tension issues anymore. She also takes off the bar that goes on top of the presser foot of her darning foot. This way the foot does not hop and glides over the fabric smoothly. I suggest taking her class or looking at her website.