flip3d454

My Feedback: (35)

i have a tower pro 1750 kv brushless and tower pro 8x4.7
with a brand new 730 tp 11.1v 3s1p.
it runs up great but at full throttel it surges out of control.
that is the recomened prop

here are the specs what do u all think it is.
need help soon.


Tower Pro 1750 RC Airplane Outrunner Brushless Motor
Model Number : P0007_1
Suitable for Props: 9 x 4, 8 X 4, etc.

Specification: Size : dim 30.6 X 62 mm
Shaft Diameter : 3mm
Weight : 46g
rpm/v (kv): 1750
C urrent range: 1.8-13A
Suggested Propellers: 9 x 4, 8 X 4
Suggested Battery: 2-3 Li-Polymer Battery

Walt Thyng

My Feedback: (9)

You don't say what ESC you are using, but most often surging, rough running or vibration are the result of incorrect timing. Most outrunners requires "advanced" or "hard"(or whatever jargon your ESC uses) timing.
Walt

flip3d454

My Feedback: (35)

it is the matched 18a towerpro esc. i dont think you can change the timming.

flip3d454

My Feedback: (35)

any help please.

flip

jdetray

What do you mean by "it surges out of control"? Can you describe exactly what it is doing?

- Jeff

flip3d454

My Feedback: (35)

it surges at half to full throttle. when you get to half stick it revs then slows way down then revs and slows down a little then revs and slows down then revs and slows almost to a stop.

the throttle stick was never oved after hit half throttle.

i dont know what to do.

jdetray

Some ESCs rev the motor up and down when the battery voltage reaches the ESC's low voltage cutoff (LVC) setting. The revving is a signal to you that the battery is getting low, and it's time to land. That could be what's happening here.

If the battery is a TP Pro-Lite 730, the recommended sustained current is 9.5A with occasional bursts to 14.5A. It could be that your motor/prop combination requires more current than this battery can provide. In that case, the battery voltage will decrease a great deal under load, possibly reaching the ESC's LVC setting.

If your ESC is one that surges the motor to signal a low battery condition, that might be what you are seeing. If this is what's happening, the solution is a battery with a capacity geater than 730 mAh or perhaps a smaller prop.

To know for sure, you should use a wattmeter or power meter to measure the current and voltage under load. And you need to learn how your ESC is supposed to behave when battery voltage reaches the LVC. Some ESCs respond by completely cutting off power to the motor, but other ESCs respond by pulsing or surging the motor to tell you that it's time to land.

Without measuring what is actually happening, you are basically guessing.

In summary, it may simply be that the battery is too small, or at least too small for the prop you are using.

- Jeff