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Motor Prop and Battery selection??

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Motor Prop and Battery selection??

Old 02-10-2011, 11:48 AM
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Doclove524
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Default Motor Prop and Battery selection??

I am looking to build a 59 inch wing span sport plane, the Edge 540 46 ARF to be exact. I am going with electric power and have chosen the Turnigy 50-55A 400kv outrunner motor. The plane should weight around 6 pounds ready to fly. I think I have chosen the correct motor and will be running a 80a ESC with it. The motor specs say to run a 14x9 prop and a 4 cell lipo. I am completely lost as far as what battery to run?? What volt 14.8? I know it needs to be four cell but what volt and what mah as well as what "c" value?? Like a 2200mah 14.8v 4cell 30c?? I get completely lost on the specs of the battery and what they mean/do??? Help if you can. Any input on my motor selection, or ESC, or prop, or battery would be greatly appriciated!! Thanks for your help.
Old 02-10-2011, 02:26 PM
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Dr Kiwi
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Default RE: Motor Prop and Battery selection??

As far as the battery goes, 4s means 14.8v nominal... typically ~13.5v-14.0v under load. Your 6lb plane could use 840W = 140W/lb. You need a pack with sufficient capacity (mAh) x C-rate (20C, 45C, whatever) to provide whatever your motor/prop combo draws. If you have an 80A ESC then you won't want to draw much more than 60A... something like 4s 20C 4000mAh (~80A) or 30C 3000mAh (~90A) would do nicely, but as long as weight is not too much of a factor bigger is better to give yourself more headroom... 20C 5000mAh (~100A) would give you longer flight times. You need to choose a prop which, with that motor and a 4s pack draws ~60A. (60A x 14v = 840W).

Most people seem to use 5s or 6s on that 400Kv motor... that would keep the amps down to a more comfortable level for it... it is rated for 68A max.... something below 50A on 5s or 6s would be good. A 14x10 on 6s is said to draw 47A.
Old 02-11-2011, 07:23 AM
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Doclove524
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Default RE: Motor Prop and Battery selection??

This is cornfusing to me?? I have read that you want a little more ESC than your motor requires, is this true? Like the 50-55A motor I amuse could run safely on a 60a esc. Should I be using a 60a instead of an 80a? Electronics baffle me!! I really just need someone to tell me what to buy and install, yet I want to understand the concept!! First off is the motor I have chosen strong enough for this size and weight of plane? What size ESC should I use...What size prop and battery combo is right for this set up?Also do the ESC's require apower source? Seems some come with batteries and some don't. I know this is a lot of info to try to "teach" someone so if thisis too much just say the word. May be better off just going to thenearest hooby shop, but someof those guys don'tseem to be up on all the latest as far as electric power goes???

Thanks for all your help guys!!

Tryingto grasp all the concepts!!

Marko

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