I have a Torque 2818/900 motor powered with an Airboss 35amp ESC and a Flightpower 2170mAh 25c 3 cell lipo. I have this in a EF Edge 540T. I have noticed that flight times for some reason seem incredibly short like less than 6 minutes flying some imac and 3D. This doesn't worry me too much, but a new behavior does. When I first take off the vertical is unlimited, but after 3 minutes or so the vertical is still good but suddenly the motor cuts out (not totally just lowers to idle for just a second or two) and then picks up again and then repeats the process. I have tried to get it to do the same in horizontal flight, but it does not. It is acting like it is taking too much voltage and the ESC is cutting off and then picks back up, but what would cause this? The motor seems to spin freely and does not seem to be binding at all. This is the recommended setup from EF, so what might be the problem?

Any help would be great. Thanks.

it may be your battery has had it

how many cycles does it have on it? How many volts does the pack read no load when you are done flying?

do you have a watt meter? if so, what is it doing when that happens?

I have 4 of the same batteries and it does the same to all 4. I can put the batteries in an even more power hungry plane and the flight times are longer and no problems at all. These batteries are almost brand new, so I don't believe it is the batteries.

No wattmeter, just have used the suggested equipment and checked for how hot things are getting.

27:

You just gotta have a watt meeter to survive, 1 pitch in prop may mean good VS death to your equipment, its very cheep insurance and you KNOW whats going on. Its a strange world out there, nothing is really what is seams it should be. I run a apc 10 X 3.8 on a small axi 2208 with 10 amp controller, 1320 mah battery. All is happy, pulls 8 amps. I take the 10 X 3.8 and put it on a axi 2808, much larger and stronger motor. Thing pulls 47 amps. Cut prop down to 9.5 and low and behold 28 amps. Your batteries may be cheepie 8C and wll not provide the power required. You want 15 to 30C for decent present quality. Lots of old stuff out there for sale quite cheep. Problem is that they simply don't have the juce! ENJOY

a couple of things then you might look at, ESC temps, or if there are any connectors that might be loose when you are going straight up that might not be making a good connection. Other than that I don't really have any ideas, hopefully you find what's doing it though.

one other thing I just looked up is that your ESC is rated at 35A and the motor is rated at 38A max cont draw, so it's probably that when you are going up you are pulling the full juice that the ESC can handle, plus a little more, so the ESC goes into current limiting mode because it'll get too hot and self destruct otherwise. You may just need a bigger ESC. A wattmeter would tell you that for sure. You might either buy one, or see if you can borrow one at the field

edit:
oh here is the link I was lookin at
http://www.3dhobbyshop.com/detail.aspx?ID=1627

A wattmeter is essential for troubleshooting. Without it, you are just guessing. It may be intelligent and educated guessing, but it's guessing nevertheless.

For $50, you can know for sure what is happening. If it saves even one battery pack, ESC, or motor, it has paid for itself.

When you find out what's going on, please let us know. We can all learn from situations like this one.

- Jeff

I have the exact same setup as you , same plane, motor, esc,and battery. I get 8-10 minutes of mixed 3-d, imac flying with no issues like what you're getting. I'm using apc 13-6.5 prop. Sounds like somethings wrong with a component, not your setup.
Hope you get it worked out!

I think it might be the prop. I was using a 12x6 slow fly prop, so I'm going to try out a 13x6.5 and see if there is a difference. If that doesn't work, I'm going to strip down the motor and see if there is some debris or dirt inside that might have damaged a bearing or something (even though it feels fine). I'm going to try to test it out in the next day, so hopefully it'll work with this new prop. If it is the motor/esc I guess the problem will become more pronounced with the 13x6.5 prop.

I believe the problem was the prop. I put the 13x6.5 prop on and suddenly I have longer flight times and no "lagging" of the motor on vertical throughout the whole flight. I guess the smaller prop was causing an increased amperage with more rpm's, but the larger prop slows down the rpm's getting it right where the motor and esc are happy. It works fine now though.