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Old Feb 09, 2013, 06:32 AM
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United States, FL, Tampa
Joined Jan 2012
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Help!
First F22 scratch build and burned motor

not sure what happened, I have a 11.1 v 500mah battery with a 2050kv motor and a 7x5 propeller...plane weighs about 9.9 oz with battery. I would only get about 3 mins of flight time per pack. The wires from the motor started smoking after third battery. ..any ideas?
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Old Feb 09, 2013, 06:40 AM
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Whiskers's Avatar
Australia, QLD, Little Mountain
Joined Feb 2010
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It looks like it is over-propped but more details of the motor will be required.
Post a URL for where you bought it or at least tell us what it is.
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Old Feb 09, 2013, 07:12 AM
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Bought it from Don at strongrcmotors.com....great guy to deal with and im sure it was all my fault. ..on his website I bought two C20 pro motors
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Old Feb 09, 2013, 02:58 PM
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Don is indeed a fine gentleman.
The prop recommended for that motor is 7 X 3.5.
Your 7 X 5 is possibly too savage. 6 X 5 may be better.
Make sure the motor is free to turn and that nothing is dragging on it and that no dirt has got into the works.
You will not get much flight-time with those little 500mah batteries. You can only get low miles from a small tank.
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Old Feb 09, 2013, 03:08 PM
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SE MI
Joined Oct 2004
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3s on a C20 with a 7" prop is definitely overpropped! If you have a watt meter, test the system and see just how many amps it's drawing. I fly several c20's but only on 2s, and even then with a 6-7" prop.
Don may chime in, but I'd think i would use at least a 24 gm (blue wonder) motor with a 9oz plane even though the F22's are pretty good floaters. A 1700kv BW will fly super with a 7x6 sf prop (it's the pick for our SEMFF warbirds and combat flyers). What do they recommend on the F22 thread?
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Old Feb 09, 2013, 10:21 PM
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As I said before, I'm sure I'm the idiot who screwed it up, I just want to learn from it and not let it happen again. Can someone recommend a good 2S battery that will work with this plane? As well as give it longer than 3 minute flight times? Thanks again and I will keep ordering from Don for more motors and other items as well! Thanks and great learning from all of you...the EXPERTS!
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Old Feb 10, 2013, 08:50 AM
Damn this gets addictive.
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United Kingdom
Joined Oct 2011
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Try reading through this. It helped me loads when I was starting out.
http://www.rcgroups.com/forums/showthread.php?t=1136470

In answer to your last question about which 2s. It is essentially a balancing act. The bigger the battery (more mah not size although they go hand in hand) the longer you can fly but you will hit a point where the weight of the battery is too much for the size of plane and the extra power required to drag the battery around will out weigh the extra capacity.
If you built from plans then go with the recommendation as the designer will have done the working out for you and will probably have used the battery to get the centre of gravity just right.
If this is your own design then you will need to play around till you get the best combination. Have a read through the link above and then come back with any questions. I'm far from an expert but I've been where you are now.

tCF
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Old Feb 11, 2013, 07:26 PM
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Quote:
Originally Posted by Thechittyfather View Post
Try reading through this. It helped me loads when I was starting out.
http://www.rcgroups.com/forums/showthread.php?t=1136470

In answer to your last question about which 2s. It is essentially a balancing act. The bigger the battery (more mah not size although they go hand in hand) the longer you can fly but you will hit a point where the weight of the battery is too much for the size of plane and the extra power required to drag the battery around will out weigh the extra capacity.
If you built from plans then go with the recommendation as the designer will have done the working out for you and will probably have used the battery to get the centre of gravity just right.
If this is your own design then you will need to play around till you get the best combination. Have a read through the link above and then come back with any questions. I'm far from an expert but I've been where you are now.

tCF
I've been flying the past two days with no issues. Put the 6x4 propeller back on it and now getting about 7 min flight times per pack on the new, but same motor that I burned. Also, learned to put the APC propeller on properly with letters facing towards front of plane. Motor is only warm after my runs! Thanks for all the help...now if I could just figure out a better fuse to make that isn't so flimsy!
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Old Feb 11, 2013, 07:44 PM
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All sorted? Good!
Ah! The old Prop On Backwards trick. We had a guy turn up to our field with a nice ARF pusher and there is no way we could get him to change his 'backwards' prop.
Explanation, logic, reason and everything else we could think of to make him understand were useless.
Perhaps a good smack in the kisser would have worked, but for some strange reason we didn't do that, we just gave up.
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Old Feb 11, 2013, 09:05 PM
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Originally Posted by Whiskers View Post
All sorted? Good!
Ah! The old Prop On Backwards trick. We had a guy turn up to our field with a nice ARF pusher and there is no way we could get him to change his 'backwards' prop.
Explanation, logic, reason and everything else we could think of to make him understand were useless.
Perhaps a good smack in the kisser would have worked, but for some strange reason we didn't do that, we just gave up.
Thanks...might try the 7x5 again installed correctly and see if there's much of a difference
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