After years of owning several radial arm saws, RAS, which I really like for 90 degree cross cutting only, I came up with this extended table. The table is secured from the bottom to 1/4" x 2" angles that run along the front and back of the saw, 5 ft long each. The left side is extended 38"
from the blade and the right side 26"
for a total length of 64"
. This makes cutting longer boards a cinch! Simply attach the angles, level them, mount the top, and start the saw by lowering it into the top about 1/8" slowly. That's your reference cut. Make certain the arm is locked securely in the 90 degree position!
Next, make a long straight fence from 3/4 or thicker stock. Locate it so the the blade will be behind the closest portion of the fence, so when you place a board to be cut, the blade will clear the board. Square the fence to the initial cut, clamp it, then screw it down and push the blade through slowly. You now have a 90 degree set up great for cross cuts. You can check your set up for square by making a cut across a 12" wide board, holding the same edge against the fence, flip the board end for end and make another cut It should be parallel to the first cut. Very slight adjustments to the fence may be necessary to get it right on the money. I know this from experience!
You can make a dust collect box at the back of table and set a shop vac underneath with a hose to the port in the bottom of the box actually the top of the table, and another to the blade guard port.
Make certain the saw is locked in the 90 degree detent before starting this!
BTW I don't recommend RIPPING on the RAS.
EDITED to correct dimension from the blade!