I started with printing "restinpieces" Ultimaker 2 knob that looks very similar. But I was not 100% satisfied with the feeling of it so I decided to design my own with the other as inspiration. My design is including the original look but also with that 1cm lofting so it's easy to grab and make choices on the Ultimaker 2, it took a few prints until I got that perfect fit. It is designed so that no support is required! TIP! The mounting is very tight and it is not certain that it fits. I recommend a 0.25 nozzle, PLA and 20% filling, because that's what I used, and even then I had to push it a bit before it slipped in. Check inside the "pin"-hole so that you are in the right direction before you press it, there is only 1 angle that will fit.