How often to clean?
I do a quick clean after EVERY project. That is, I use a stiff brush and remove the lint from between the needles and the bottom of the carriages.
The lubrication is “gun oil”, a very fine thin oil. It is recommended that one does NOT purchase the spray version as it has silicon that ruins the plastic parts of the knitting machine. Clean the rails, lubricate the rail, and the moving parts of the undercarriage.
After removing lint, it is worthwhile to inspect the “brushes” that they do not have yarn wound around them and not turn easily. If they are not turning easily, remove of the screw and release the wound yarn. Lint also tends to build up around them. DO NOT LOSE THE SCREW. If it is lost, you will need to contact a knitting machine dealer for replacement. It is not a generally available screw from the hardware store.
The NEEDLE RETAINER BAR needs to be replace periodically. Some brands of machines sooner than others.
For a DIY project, this is the size of foam that fits the Studio Standard gauge knitting machine. Other knitting machines may use a different sizes. It is found in the weatherstrip area of the Hardware store. This particular brand is self adhesive.
Lastly, cover your machine if you are not continuing to use it immediately. A towel or bedsheet works well. Knitting machines don’t care for house dust.