Hi Roger,
I'm very glad to see you are getting your ECL plane ready. :-)
1. RE: the mAh needed. ...... I know that some have flown the pattern with very small mAh of energy used (some at the ridiculously low 2,200 mAh?), but my guess is that these are with very light, sleek, relatively thin winged, medium size ECL planes. My experience has been that a higher drag plane like my profile, relatively thick wing, P-40 with everything hanging out in the breeze, uses about 2,850 mAh per a 5:30 min. flight pattern. The T-Rex with a "real" man size looking fuselage and a relatively thick airfoil wing, will tend to use more mAh per pattern than the above sleek, thin, smaller planes. My guess is around 3,000 mAh will be needed. Using the safe 80% rule, this would mean a 5S battery of at least 3,750 mAh would be needed.
I like to have extra headroom everywhere and never make my equipment work too hard. Therefore all my batteries are 4,000 to 4,200 mAh. I would rather have a few extra mAh, even at the cost of a few oz. Our planes can easily handle a few more oz. considering the almost unlimited power we have in ECL. :-)
2. RE: your motors ....... I would go with the 650 Kv with your 5S battery. This gives you a max RPM of 12,000. Using the conservative 80% of max rule you get 9,620 RPM. This is a good sweet spot for us. I feel that 8,500 to 8,800 RPM will even be better because it will be quieter. This is the RPM I hope to prop for.
After watching, and hearing, Paul Walkers beautiful ECL plane, I am convinced that we can fly with unlimited power and still be very quiet. And watching Dave fly many times has made me a true believer in having a LARGE power source that never lets the plane slow down or miss a beat in the pattern. Just the opposite of using a felon fox .35. I have installed an Orbit 25. Paul told me that my Orbit 30 would be too much, he had already tried it. He uses the 25 and I saw it pull his plane like a freight train. BTW, to watch Paul and Dave fly is like watching Michelangelo painting beautiful, perfect figures against a cobalt blue sky with a 70' paint brush. :-)
IMHO: don't be shy about using a lot of power. Dave proved to everyone how well this works. If you like your Turnigy motors then use one that is = to at least a .60 wet engine. The motor, plane, and the pilot will all be much happier with a system that is not always having to run at max speed, heat, etc. ;-)
Bob,
I am very sorry to hear about your WX issues. This puts a damper on your testing I'm sure. Look at the bright side, Your beautiful, green, flower filled MI Spring is just a few short months away, and you have a better "building season" than we do! :-) ..... Last week it was 73 and sunshine with string bikinis worn here at the beach, BUT ..... to make you feel better, it rained all day today, it is a freezing cold 59 degrees and it is forecast to rain all week! This will be my entire years building season, so I better get cracking on my ECL plane ..... removable wing, tail, exact scale paint scheme, YIKES! that means at least 200 hours of work for me ( 180 hours thinking about it and 20 hours of actual work!
)
Warm Regards,