I worked on an Edison clone yesterday. It was VERY dirty and didn't spin freely. The Edison decal was coming off so I scraped it slightly and got all of it off the used buffing compound and she looks Amish. Once I got it cleaned up enough that it felt ok to touch, I took apart the tension and put in a new spring since the old one was sprung way out of shape. The bobbin area was easy to clean as usual for a clone. Then I took the spring off the bobbin case - I'm so glad I did - just a little bit of nasty dried on oil. The machine needed considerable amounts of oil before it turned very well. When it finally did turn is spins VERY freely. I haven't test sewn yet - it still needs a working motor. Typical clone.