I had a real struggle trying to print ninjaflex on the rostock max v2 and even with the filament support mods people suggest I didn't have any luck. I designed this extruder and so far it hasn't had any issues with printing soft or normal filaments. I used the factory red lever from the Ezstruder assembly along with its spring and other hardware that I had left over from the rostock kit. If you don't have any of that hardware around you can easily source it at a local hardware store.You will have to drill out the bottom of the extruder to the right size hole to self tape the tubing coupler into the extruder. I found it was best to tap this by hand instead of trying to print a hole the right size. It works but after a while it may weaken.. so far by drilling and taping the hole by hand this has worked out with no problems. The rest you can see from the photos.. I used two zip ties to hold the nema 17 motor in place since the rostock mounts were now gone. This has proved to be more than sturdy so designing motor mounts never happened.