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Motor timing and the effect of it....?

Old 12-16-2009, 04:58 PM
  #26  
Some Useless Geek
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Don't forget the existing database on RCG:

http://www.rcgroups.com/forums/showthread.php?t=966298
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Old 12-17-2009, 04:03 PM
  #27  
bassmanh
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Default motor timing and amps ?

hi,

just wondering if using different timing settings will affect the amp/watts output of a motor ? all things staying the same, IE prop,batteries, esc ?

thanks


bass
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Old 12-17-2009, 04:23 PM
  #28  
Larry3215
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Originally Posted by bassmanh View Post
hi,

just wondering if using different timing settings will affect the amp/watts output of a motor ? all things staying the same, IE prop,batteries, esc ?

thanks


bass
To a small degree - yes.

Typically, you might see as much as a 10% to maybe even 20% variation in amp draw from the "best" timing setting to the "worst" depending on the motor and controller your using.

However, you rarely see much difference in RPM - which is what you really want to know if performance is your goal.

Most of the "extra" amps simply go into heating the motor instead of making the plane fly faster.

If your after more "flying power" in terms of faster flight or faster hover pull outs etc, then you need extra RPM - not JUST extra amps.

An increase in amps without an increase in rpm = heat.

Thats why I said earlier that you need to test every setup with a Watt meter AND a tach.

Changing the timing so that you draw more amps and the watts goes up may be exactly the WRONG thing to do to make your plane faster. You may actually be lowering the rpms while drawing that extra power.

Like I said - there are NO fixed rules that apply in every case for every motor and every esc.

Sometimes increasing the timing is good and sometimes its bad.
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Old 11-02-2010, 09:34 PM
  #29  
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Im sat here with my EZ* fitted with an Overlander Tornado BM400-2200kv Revolution Inrunner 16wind, a hobbywing 40a ESC pentium, a programme card and a turnigy watt meter, and after reading all the above im still rather clueless on the timing option.....

default is low,

I thought id post up some results:

2200kv motor,
40a esc
6x4 emp prop
10.8v Intellect 9 cell 1600mah nimh

Timing results are with EZ static in hanger and at full throttle for 10 second burst.

Without any throttle input

Amp peak :0.03a
Volt : 11.98v
watt peak :0.4w

LOW TIMING:

Amp peak : 13.13a
Volt : 9.23v
Watt peak :127.7w

MIDDLE TIMING:

Amp peak : 13.12a
Volt : 9.21v
Watt peak :121.6w

HIGH TIMING:

Amp peak : 14.22a
Volt : 8.87v
Watt peak :127.1w


All taken within 1 minute of each other on a fully charged battery.

Still unsure in which setting to use....gona stick with low..... i think

Last edited by HOODY; 11-02-2010 at 10:23 PM.
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Old 11-03-2010, 12:03 AM
  #30  
tobydogs
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if the 50-55 580 is a turnigy sk motor,than the 80amp esc is the recomended size.....but i always go to a larger esc's so i went with the sentilon 100amp esc from turnigy and set the timing to high.runs great.

timing thats off will cause operation issues such as screeching motors at different speeds.

did you check the amp draw with the six cells with a watt meter?
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Old 11-03-2010, 02:12 AM
  #31  
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hoody,i just realized i posted after only reading the first page ....opps...,my post wasn't directed to your post since i realized it as soon as i saw your post. anyway,i to haven't figured out the best way to determine timing setting....most esc's have 3 choices and 1 outa 3 will sound better....thats how complicated i get.

next time i'll be sure to read all the pages before posting.

by the way....i'm always keepin an eye out for those pictures/videos you do.
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Old 11-03-2010, 02:37 AM
  #32  
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Which settings are "best" will depend on what you are trying to achieve.

However, you dont have enough information to decide anything yet.

Just measuring amp draw, volts and watts doesnt give you enough information to decide which is "best".

You also need to know the rpm you were getting with each different setting before you can make any meaningful comparison.


You had the highest watts with the lowest amp draw - probably because your pack is being pushed too hard or it was the first test you ran.

BUT - was that setting giving you more or less RPM than the other two settings?

Its the prop turning through the air that moves the plane. You want to get the most rpm for the least power to have the most efficient setup.

The middle or hi timing MAY be giving you better performance - but yuo will never know unless you measure the rpm,

It could just as easily be that the highest power setting or the highest amp draw is pushing the motor into an in-efficient range and you are just dumping that extra power into heat - instead of turning the prop faster.

Any power that doesnt go into more rpm is just heating the motor.

On the other hand, lets say your after max speed - then you dont really care about efficiency, but you still need to know the rpm. Its the rpm that gives speed - not watts.

if your after maximum flight time, then you need the lowest amp draw - but wait - maybe not. Maybe that lower amp draw is running the motor on the low end of the efficiency curve and you actually getting toooo much of a drop in rpm.

So... no matter what "best" means to you and how you fly - you need to know the rpm of the prop or that watt meter reading is useless
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Old 11-08-2010, 01:16 AM
  #33  
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I just start with medium. I put a very short leaded ammeter in the + battery lead. Run it up in speed SLOWLY. I watch the meter for faster amp changes & listen for motor sound changes. I stop the motor & move the timing 1 step either way. Restart & check change of amps again. If better, I continue the timing changes in that direction.
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Old 11-15-2010, 08:22 PM
  #34  
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Hoody, you need to get rid of that NiMH pack. That boat anchor is not capable of holding voltage at less than 10C discharge rate! Any decent modern LiPo pack will give you that at a minimum, and the 20C 3S packs from Hobby King are quite cheap as well as offering great performance.

Next, you need to measure RPM, as Larry has already pointed out. You might be able to borrow a tachometer from somebody in your local club. If not, then you need to use some way of recording the sound created by the prop and comparing one RPM to another that way. Even a cheapo smart phone can do that.

Motor timing doesn't exist in a vacuum. Get all your data recorded and then you can compare one setting to another to see which one gets you closer to your overall goal.
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