Originally Posted by Crossstitcher
That hole in the back with the plus and minis looks like it could be something to do with the tension. I don't see anything that looks like a tension on the front of the machine. Just my thoughts.
That's a best guess on the other thread, too. It still might be, but there is a tension knob in the front, at the top of the thread uptake. Only the numbers show, the knob itself is behind the front faceplate door.