propeller mounting

I've read many posts of members using a 6x3 prop on an 1806 motor. Here's a bad picture of my result. The thickness of the prop's center section won't allow the nut to tighten down to the nylon locking insert. What am I missing here? The motor and prop came from FT.

Can you do that ? I've been looking around and can't find the answer, at least I couldn't find anyone saying "don't do it". I bought a PROPDRIVE V2 2826 1100kv Brushless Outrunner Motor and it comes with a shaft pressure adapter and a 3 bolt adapter, and naively I think that mounting the...

I feel like I've been really messing up in my selection of prop mounts and the choice of nosecones. Is there some kind of a guide for how this is to be done? It seems to be a haphazard affair for me, and I have learned little. I just kind of cobble something together, which usually does not...