Use a thinner 4 ply such as Caron Simply Soft, or a 3ply sport
weight yarn.
Push out every third needle on both beds to
just short of the 50 mark. Be sure your main
bed needles are outermost on both sides. Cast
on at tension 3, hang comb and weights, then
set your carriages up for circular knitting.
Let your tension out to 8, then knit 120 rows
for a child's hat, more for an adult (keeping
in mind that it takes 2 passes to get one row
around the hat).
Leave a yarn tail long enough
to go around your stretched hat, and pass it
through the stitches using a large embroidery
needle (be sure to go through the loop of the
last stitch first so you don't unravel as you
stitch!). You may find it easier to run a couple
rows of ravel cord, drop the knitting from
the machine, and then pass the yarn. Tie the
end and hide it in the brim, then stretch the
hat into shape. The brim will curl up, making
a great 'grow-with-me" hat.