Dene Collett wrote: > Exactly why or how did they break? Was it > failure of the taper due to gyroscopic forces?
I don't know HOW they broke, but I do know that one of them broke in the middle of a journal so it was basically captured, which kept the prop from flying off. Torsional vibration is my first guess, but I don't know. > Mark, respectfully I think you have missed what I plan on doing. I have > designed a support structure that will house a double ball race, self > aligning, sealed bearing... I realize that. It's the torsional vibration issue that worries me most. When you bolt anything onto the crank solidly, you change the dynamics of the system, and you're in uncharted territory. Of course, that didn't keep ME from bolting a pulley and a Nissan Sentra flexplate to my harmonic balancer hub, did it? So I guess I have no room to preach! > William says "flying is risky", all we can do is keep that risk down to a > minimum by not being irrisponsible by thinking we know it all no matter who > we are > or how many qualifications we have.( Please don't take that as a stab at you > because it honestly isn't) No problem there. I certainly don't claim to be any kind of super engineer. We all know our little niche well, but once out of there, we're just like everybody else, we have to do the research and come up to speed. Your first clue that somebody's blowing smoke is when they justify that they know what they're talking about because they're some kind of engineer! I know some mechanical engineers that don't have clue how an engine works, or how to get in out of the rain, for that matter. > You are right on the money here, I am working on a shoestring budget and > only have limited resources when it comes to machining. Understood, and if you have free machining and welding available, that's a big help. > Mark I am not aiming at proving you or anybody else wrong and I certainly > won't crow about it if by chance I do succeed, but it should be noted that I > am literally miles away from having anything to attach this motor to in > order to go flying behind it. My 2S is a long way from flying and I > certainly won't stick a motor on the front of it that I was'nt reasonably > sure will pull me around the skies as safely as I can make it possible. If you pull this off and it works great, you'll have every right to crow about it, and I hope you will! There are several ways to build an airplane. One is follow the tried and true and buy stuff that'll get you in the air soon, and the other is build and/or design as you go and don't worry about when it flies. Whatever works for you, and I wish you the best of luck with it. Please feel free to keep us informed on how it's going. You're right, that's why they call it experimental... Mark Langford, Huntsville, AL N56ML "at" hiwaay.net see KR2S project at http://home.hiwaay.net/~langford