My tech. told me if we really feel we need to "shortcut" the oiling frequency on our FW's., if we just oil the bobbin parts, that is acceptable.
He showed me to just take the bobbin out, and oil the little places that have cut-looking pieces. That isn't a very good description. If you take the bobbin out and look closely, you will see what I mean.
He said to oil those after every use of your fw. I agree; you can hear your machine "tell" you that it needs oil.
Mariah