I have the same problem, except for me I cannot remember which type of needle is in which machine. So, I created two ways to keep track. First, from an empty spool, I wrote in different sections the type of needle and then made a cover that spins out of plastic that has a clear window. I select the type of needle for that machine and keep it on the extra spool pin. The second idea uses a wheel, like we used to have in elementary school to learn addition or times tables. It has the bottom circle sectioned to show the different type of needles. The top section has a pie shape cut out to show the needle type (like PacMan). I can then write the name of the machine on the top circle. I put them together with a grommet, so I can turn the top circle to show the needle type. I am going to try to attach pics.