Nope, they don't all fit eachother. I have the 3160QDC and the MC6600: the 3160 is low shank whereas the 6600 is high shank so not all feet will fit both. Plus some models have wider feed dogs and/or wider zig-zag openings and need wider feet than others.
Janome's site is a great reference though, you can look up your machine and get the accessory part numbers that fit your machine and use those numbers to shop around for best price on the foot/feet you're interested in.
....well, shoot. I just went to the site to give you a quick link and they've totally changed it around. I found your machine, and found the foot in the list (they call it an "even feed foot"), but when I click on it I get lists that don't include your model! LAME!
You might want to call your dealer to get the right part number. Or maybe try emailing Janome directly. I'm really disappointed in what they've done to their site...
