I did exactly what you are doing, and I cut the hole open at the front of the desk so the machine sits completely forward and I can pull it out on the keyboard tray to use the free-arm occasionally. Be sure to leave enough room for the machine's cords so you don't crimp them. I didn't leave quite enough space between the keyboard support and the machine and was crimping my cord badly - had to get a different cord that fit in the space.