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Old 07-16-2017, 07:23 PM
Pull Up Now!
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Join Date: Aug 2008
Location: Northfield, MN
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Originally Posted by TimD. View Post
Pull up ,
I truly respect you on investigating the airframe needs. It will help many people out. That is what the forums are about. I occasionally do write ups as well. The need for more power is an arguable debate. In my perception, the less weight trade off versus more power, I tend to go on the lighter side . The extra engine weight also requires more fuel and that equals 5-7lbs more extra added weight. Is the airframe going to last longer while enduring higher stress levels ? IDK.
I remember flying 20lb models on 7-10lbs thrust and Yes I can be done and it works ! Longer take offs and staying on the power. This is for each to figure out on their own.

I did not know Mike was selling gear for it. I bought the Robarts because there was not any other options at that time. I have had their Warbirds and agree their stuff is Nice and fits perfectly. They designed it for that plane specific. Robarts is a retro fit setup. I will call Mike to order the TopRc gear set myself

Did you plan to use air or servo operation for the body flaps? I was going to do servos.
The part numbers on many of the Robart components were labeled Caiman F9F Cougar, so they must be somewhat custom.

With the 80N engine, I did run some numbers based on my flying habits. The engine uses about 8.4oz fuel/minute at WOT. The tank is 64oz, so at average 75% throttle that gives me a 9 minute flight with a minute to get down. Most of the time my average is probably 60% throttle. Added margin. I've always modulated the throttle, even with propellers. Yes, I see guys who just burn up the sky the whole flight, but that completely omits a whole dimension of flying skill. So I didn't feel the need to enlarge the tank and thus add more weight. Here's a pic of the tank.

As for the flaps, I just used servos. I accidentally glued the control horns on a different distance from the hinge line, so to equalize the travel I had to customize the servo control arms.
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Last edited by Pull Up Now!; 07-16-2017 at 07:31 PM.
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