RE: Prop for H9 Alpha 40
When my students decide to change from the 3-blade to a 2-blade prop on their Alpha's, I tell them that the Hobbico NextStar 11 X 5 prop is one of the best you can use. I've tried the APC, MAS and Evolution props and found the NextStar prop the best for overall performance on the Alpha. Plus it was the cheapest cost wise of the bunch. An added bonus is the red tips are visible when it's running to help keep fingers out of the prop arc. The NextStar prop will work on a grass field with no change to the wheels.
In order to fit a lot of spinners, you'll have to either remove the flywheel weight (it'll slip off by placing it on a vise opened wide enouth to alow the hub to slip through yet support the flywheel, and using a socket, knock the hub out of it into a rag), or spend the $3.00 for a new hub.
Hogflyer