RE: Estarter Build Help
As I recall the instructions, yes, the 400 is supposed to go into the bottom slot, but there is an Estarter at the field I fly that has it mounted in the top hole. I don't know if the fit was any better though.
Yes, GWS does some weird things with the props. They assume you know about drilling or reaming them out. You'd think that they would supply props that fit the shaft....
There are different theories on how to put the nuts and washers on.
I put the nut on first followed by the washer then the prop and then the nut. This way, the nut on the outside tightens as the prop turns. The downside to this is that if you have a brake on your ESC, when the prop stops quickly, the prop can spin off. Therefore, some put the nut on first followed by the prop and then the washer and then the outside nut. Spinner always goes on last, of course.
If I felt my prop was in danger of spinning off, I would simply snug another nut against the last one that threaded on.
But, the downside of going nut, prop, washer, nut, is that if the outside nut loosens up for any reason, you will strip the indentation in the back of the prop which renders it useless. This happened to me, which is why I use the method I do. I've got over 50 hours on a Slow Stick, 10 hours on a Formosa, 30 hours on a GP BLT and 36 hours on my Estarter with this set up and never had a problem.