Mark everything I post is in word. Spelling and grammar should be correct. Unless I have the propeller custom made. The largest zinger makes is a 32x13. That is what Toni Clark in Germany makes for the Zenoah G38. I am using the 42cc Poulan chainsaw engine. I am trying to recreate what they have done. For the Poulan! Good point on the thrust load on the bearings witch is only 24lbs. I can test that by pulling on the shaft when done. The final test will be on a test stand with a couple of tanks of gas. And when the plane is completed! I will conduct a thrust test with a fish scale tied to the aircraft. But any help is welcome especially form a professional. As it is all new to me!