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Electric Stunt => Gettin all AMP'ed up! => Topic started by: GerryG on July 11, 2019, 11:45:03 AM

Title: What is going on Here?
Post by: GerryG on July 11, 2019, 11:45:03 AM
I have been looking at a number of entries in the List Your Setup thread. My plane is a profile Cardinal with slightly cutdown flaps. It is set up in a very similar manner as Bob Hudaks Legacy 40. Similar motor, lines, prop, weight, lap time, flight duration, etc. The only obvious difference is the speed controller and timer. Mine has an Arrowind 60a ESC and KR governor. My battery is a Lectron 3000 and I using 2600 mah per flight. Any suggestions as to why the mah usage is so high.
Title: Re: What is going on Here?
Post by: Bob Hudak on July 11, 2019, 12:13:38 PM
Need more info. What prop, rpm, line length and run time? These all have effects on battery life. How similar are the motor and settings? The Emax motor I am using has 14 magnets, I bought a Turnigy with what I thought was similar but it only had 8 magnets rendering it useless(very inefficient).
Bob
Title: Re: What is going on Here?
Post by: GerryG on July 11, 2019, 12:29:27 PM
The motor is an Arrowind 2826 850 KV. The lines, times, weight, prop are identical or very close to your Legacy 40 setup.
62' / 015 lines, 5.2 lap time, 11.5x6 APC F2b prop (cut down 12x6), 53 oz flying weight. I have used an E-flite 25 on a Dixon Cardinal with a little lower battery usage. I guess the question is what is the effect of motor and/or ESC selection on battery usage?

Title: Re: What is going on Here?
Post by: Motorman on July 11, 2019, 12:32:21 PM
Profile has more drag. The KR gov has gain so uses more for the boost.
Title: Re: What is going on Here?
Post by: Tim Wescott on July 11, 2019, 12:59:26 PM
How many cells?
Title: Re: What is going on Here?
Post by: Brent Williams on July 11, 2019, 01:10:17 PM
Total flight duration?
Title: Re: What is going on Here?
Post by: GerryG on July 11, 2019, 02:32:10 PM
Sorry for putting all the info.  It was the same as Hudak's Legacy 40 write-up.
Battery: Lectron Pro 3000 4s

Flight duration: 5min 30 secs.
Title: Re: What is going on Here?
Post by: GerryG on July 11, 2019, 02:33:03 PM
Should read: Sorry for not putting in all the info.
Title: Re: What is going on Here?
Post by: Bob Hudak on July 11, 2019, 04:46:18 PM
I can't  nail what's causing your higher battery consumption.  If I had to choose one it would be the battery. I am unfamiliar with the Aerowind ESC, the Aerowind motor is identical to the Emax. I doubt the timer could cause excessive battery consumption. So it is most likely the battery not delivering as promised.
Bob
Title: Re: What is going on Here?
Post by: GerryG on July 11, 2019, 05:12:40 PM
Thanks Bob. I do have one other battery of suitable size so I will try it for comparison. I haven't used it because I have four of the Lectrons and wanted to use the same batteries (different ends, etc.).
Title: Re: What is going on Here?
Post by: pmackenzie on July 12, 2019, 12:22:09 PM
How are you measuring the capacity used?
If you are basing it on how much goes back in while charging, and using a "balance" charge made that can show more than was actually used.
Particularly if the battery is bad and one or more cells is worse than the others.
Title: Re: What is going on Here?
Post by: William DeMauro on July 12, 2019, 12:47:31 PM
It's difficult to diagnose because any one of these solutions could be correct. So I'll just add a few more ideas that I haven't seen mentioned yet. Possible bad bearings in motor; out of balance prop or spinner and collet not turning true; Was this info based on more than one flight? Was your battery fully charged to start with? How old is your battery? As in age not"Well I bought it 5 years ago and only flew it 3 times" Profiles do have more drag as stated above, you have to compare profiles to profiles. If all is well I would think that that setup should use 2000-2300mah max with the setup you describe.
Title: Re: What is going on Here?
Post by: Motorman on July 12, 2019, 01:29:35 PM
If you are basing it on how much goes back in while charging, and using a "balance" charge made that can show more than was actually used.

I did not know that. How do you measure what you're using? Is there another charger mode that works better?


Thanks,
Motorman 8)

Title: Re: What is going on Here?
Post by: GerryG on July 12, 2019, 02:16:43 PM
Thanks for the reply guys. The mah used was based on the amount put back in using balanced charging. The battery is just over one year old and the cell checker indicated all cells were fine. The prop was carefully balanced and spinner seems good. Will check the seating of the collet. The big usage occurred on all three of my pattern practice flights that day. The motor runs smoothly and quietly but I will check the battery usage on a similar plane that has a different motor on it. Thanks again.
Title: Re: What is going on Here?
Post by: GerryG on July 14, 2019, 08:08:29 PM
Used the batteries in one my Vectors today and they came through great. But looking closer at the way the prop was installed on my Cardinal revealed that the collet was not seated completely. I had used one of those bullet-shaped prop nuts and probably didn't tightened that little bit more that was needed. Thanks for your suggestion William, to look at the collet.
Title: Re: What is going on Here?
Post by: Motorman on July 14, 2019, 09:07:24 PM
Make sure that part that comes out past the drive washer has clearance in the prop hole. Also if you tighten too much the aluminum shaft can snap off.