Using a radial arm saw for rip cuts is very much like making rip cuts on a table saw, except that the saw blade is mounted above the table rather than coming up through the table. When I first began to use a radial arm saw, I found I needed to pay special attention to brushing away sawdust and wood chips that gathered on the table at the fence. As with a table saw, a splinter of wood caught between the fence and the work piece affects accuracy.
The radial arm saw motor has an in-rip and an out-rip position. Choose the one that is most comfortable for your job. The in-rip position places the blade end of the motor closer to the fence. The out-rip position places the blade end of the motor nearer to the front edge of the table.
The front edge of the table can be used as a saw guide for special ripping operations, as when the edge of a panel needs to be made true