ORIGINAL: Mttvannest
If it is a plastic spinner just enlarge the openings to let the blades fit.
True. Most spinners are designed with small openings so they can be used with small props.
After all, you can make the opening larger if you have a big prop, but you can't make it smaller if you have a small prop.
A Dremel tool is perfect for this. If you don't have one a round file works best.
Avoid any making any sharp nicks in the plastic.