Oiling and Cleaning
If you own a Bernina 830/820 please click 
here
If you own a Pfaff Grand quilter please click here
There are basically three different hook systems in household sewing machines.
Rotary hook front/side loading, Rotary hook top loading or drop in bobbin and CB hook machines.
If your bobbin case looks like this 
you have a CB bobbin case. Please click here.
If your bobbin case looks like this 
you have a rotary hook system. Please click here.
If you have NO case to take out of your machine and you just drop your bobbin into the machine and it looks like this 
you have a drop in bobbin. Click here.