15 size speed plane( my own design), & prop question
Well, I ordered the APC 6.5 pylon props in 5.0, 5.5, 6.0 and 6.5 pitch to try all 4.
I also think that once you start running a small prop upwards of 22,000 to 30,000 possibly that thinning the hub is scary. Thats why even the "sport" apc props I wont modify except cut down.
The easiest/safest way to get the thicker hub on the engine is to buy or make a sleeve nut, that will fit into the hub (after you ream it out) and give enough threads to hold securely.
I will not have the props for 2 weeks or so (out of stock) but will post some RPM's when I get them.
Andrew