All the embellishments for the Instructable Robot Hat were crocheted and sewn onto the hat with a yarn needle.
Use a smaller hook size (for me that's a size G.)
I used my Instructable Robot shirt to copy the facial components. The left eye is smaller than the right eye as you look at the shirt, but I know on many of the robot-icons this could be interchangeable.
With red, ch 12, be careful to not twist the chain, sl st in first st and finish off with a long end for sewing.
With red, ch 15, be careful to not twist the chain, sl st in the first st and finish off with a long end for sewing.
With black, ch 20. Fasten off. Leave a long end (about 12-inches or so) for sewing.
With black, ch 22. Fasten off. Leave a long end for sewing.
Antennae (make 2):
With black, ch 15, turn; hdc in 3rd ch from hook, sl st in top of each st to end. Finish off. Leave a long end for sewing.
Side Knobs for Antennae (make 2):
With red, ch 3, sl st in 3rd ch from hook to form a ring.
Ch 3, 11 dc in ring, sl st to top of ch 3. Fasten off and leave a long end for sewing. Turn the knob onto your finger to shape before sewing onto side of hat.
Use a photo of the robot as a guide.
Sew eyebrow first into row 14 of body.
Sew the larger eye just below eyebrow (using photo of robot as a guide.)
Sew the smaller eye beginning at row 13 or just between row 13 and the top of 12.
Sew the antennae at the edges of hat on row 9 of the body, BEFORE sewing the knobs. Sew both sides. While sewing the antennae, I weaved the yarn end through the antennae and back down again, to stiffen the antennae to stick out straighter.
Push the antennae through the hole of the knob so that the antennae is centered on the knob. Sew the knob around the antennae. Sew both sides.
Sew the mouth between rounds 4 and 5.
Sew in all loose ends.