In no particular order, here are some things I've learned about the Mirella:
- Straight stitch only, with reverse
- Rotary hook
- Mirella-specific bobbins required; no longer made and very scarce
- Low shank, but Singer attachments don't seem to work well
- Motor is difficult to access
- The body is made of aluminum, so the machine is extremely light and easy to carry
- The free arm is accessed by unscrewing a knob underneath the machine and removing the extension. A separate cover is provided to protect the bobbin area.
Accessing the gear area on a Mirella, or on one of its sisters (such as the Lydia or the Silvia), requires loosening a set screw in the knob located in the middle of the handwheel. Then the knob can theoretically be unscrewed by holding the handwheel steady with one hand and loosening the knob with the other. In actuality, this proved very difficult. I eventually got the knob free by removing the set screw, oiling with Tri-Flow through the set screw hole, cushioning the knob with a rubber jar gripper pad, grabbing the pad with pliers and applying force. It took some effort!
With the end plate removed, you can see the very simple inner workings of the machine. If this were a Lydia or a Silvia, you would see the nylon camstack between the top and bottom gears. This camstack is very often cracked and is no longer made. It is my understanding that repairs are all but impossible. If the crack is small, the machine can often operate and perform some of the stitches but not the ones controlled by the cracked area.