I agree with RCKen on the durability of the glass reinforced nylon props. Master Airscrew makes some very tough props that will last. Another good prop for a .46 engine is the Hobbico NextStar 11 X 5 prop – it’s the one with the red tips, and is $.50 less expensive than the MAS 11 X 5. The black glass reinforced nylon, while maybe not as effecient as an APC, is less brittle than the APC and IMHO is the better way to go for a prop for your trainer. I recommend the NextStar prop to my students as I’ve had very good luck with it, it takes the abuse and the red tips are visible at idle speeds helping to remind students this is a prop spinning along at 2400 rpm.

Hogflyer