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Old Mar 15, 2006, 09:20 AM
Cary Reeves is offline
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United States, UT, North Logan
Joined Jun 2004
1,288 Posts
RL: Which version are you building? 30"/3mm or 40"/6mm?

I built the larger version from FFF. To get the nose to fit, I gently curved the tabs on the front of the fuse and the front cowl piece before putting the cowl piece in place. It then fit together fairly easily. I held it with Scotch tape while I glued it. After the glue dried I went back with a hobby knife and trimmed off any high corners and then lightly sanded the joints. As you can see in post #123 it faired in pretty well. You can see the joints, but that is true all over the plane. I made it worse with my paint choice since the blue and yellow contrast so much. I little light weight filler would have done wonders for the nose joints.

WRT props. I'm using a small motor on mine and ended up with a MUCH larger prop than recommended by the motor supplier. I worked up to it and carefully watched the static amps and the temperature of all of the components on landing. I went to a very low pitch so I could get plenty of diameter to clear the wide fuse. I thought I was crazy until the guys on here confirmed that as long as it's running cool it should be o.k.

Interestingly, I found that a large diameter low pitch prop worked out well but some smaller diameter and higher pitch props didn't. With the high pitch props, everthing ran fine static but my ESC kept shutting down in flight. The explanation from Gene and Brad is that the high pitch props are stalled static but not in flight and in the unstalled condition they pull more amps than the rest of my system could supply. Consistently, with the higher pitch props, the motor was warmer on landing than with the low pitch prop even though statically the amp draw was about the same.

I'm also beginning to realize that the recommendations given by the sellers are just a starting point. Some under rate the motors by a fair amount. Others push them as far as they can to see what happens. I would probably under rate them a bit too if I was a seller to try to limit returns from people frying them. A great example of this is the 450TH sold by JustGoFly adn the 450TH sold by Balsapr. They are branded differently but I believe they are the same motor made by EssKay? Balsapr rates it at 16.5A; Vinnie at JustGoFly has tested it extensively and rates it at 29A and 300W! He shows test data up to 350W or so. Vinnie has taken the motors to failure and posts data for a large variety of props direct drive and geared and a wide range of voltages. He has gone to great effort to find the edges of the motor's envelope and then give his recommendation for the upper limits. He is taking more risk but providing tons of useful test information and real world flying results. No knock on Balsapr, they are also one of my favorite vendors and give great service, selection, and prices. Just a different approach.
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Last edited by Cary Reeves; Mar 15, 2006 at 09:43 AM.
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