You can't increase a complex Turks Head like this. The way to make a larger one is to make a larger regular TH, and then close the ends. I learned how to tie these in hand, and my Grandfather called it closing the ends, so I call this style of knot a closed end TH. Tying the knot is a two step process, first you tie the base knot, then use a second line to close the ends, then remove the original knot.
This knot started out as a 7 Lead x 8 Bight TH. Then I took a second line and started to double the plies. On the first pass going up the knot, I then skipped two bights, and then followed that lead down. I skipped another two bights at the bottom of the knot, and followed that lead up. The next pass had no skips, it was just a straight follow up, and then follow down. The next pass up was skip two bights, follow down, skip two bights follow up, then follow, follow. Repeat this pattern until you arrive back at the beginning. Then remove the original knot, and you are left with the globe knot. Double the plies as needed, tuck the ends to make hiding them easier, and tighten up.
Pat