Dimension of Kitchenaid Attachments Square Shaft

Hi all,

I am looking to design my own attachment for my Kitchenaid mixer, but I need to know what the dimension of the square shaft is that fits into the mixer. See what I circled in the picture attached. Does anyone own the pasta maker attachment or similar (with a metal square shaft) and could measure it with a pair of calipers? I need a precise measurement if possible. Thank you!