ahmoser

anyone had trouble with an e-flite park 400 brushless motor sputtering from no throttle to about 1/3 throttle? After that the motor spins great. What could be the cause of this and how can I fix it? Thanks

Ashley

ahmoser

just to clarify I'm using a 3 cell lipo and a 20 amp speed control.

coolbean

What kind of speed controller? You might see if you can adjust the timing.

Troy-RCU

My Feedback: (1)

Some controllers don't like certain motors so that is what we call a rough start. It's sometimes a setting, sometimes it's just something you have to live with...these motors are sensorless so timing on start up is done through very complicated back EMF readings from the motor. It has to figure out what the motor is doing in fractions of a second so it joggles the motor to get that back EMF reading and then it's good to go. Sensored motors never had this issue but sensored motor systems are not as "plug and play" as sensorless. See if your speed control has a "soft start" setting or as mentioned check suggested timing mode.

ahmoser

I'm using an e-flite speed control, not sure if I can or how to adjust timing. Thanks for the help guys.

Troy-RCU

My Feedback: (1)

Looks like timing is auto set. The only programming options are for a brake and lipo vs. Nicad/NiMH cells. If it's really bad then you may want to check with others who have this set up to see if they are experiencing rough starts with that motor.
http://www.horizonhobby.com/ProdInfo...rushlessV2.pdf

Is it the Outrunner or Inrunner Park 400?

ahmoser

It's the outrunner. I guess I'll just have to live with it. Someone said the magnets may be out of line. Have you heard of this?

Troy-RCU

My Feedback: (1)

Double check all of your connections from the esc to the motor just to be sure. Any sources of resistance can makes matters worse. I suppose you could have a wierd issue like that but E-flight has pretty good quality control on their product. I am no expert on motor design but in my experience some motors just do funky things depending on the controller used. Just recently my buddy had a very high efficiency, high power motor mated up with a very high quality speed control (Shulze) and experienced hesitation or sputtering at takeoff . Once in flight the combo ran better but it always occured on takeoff and when going from zero to full throttle. The speed control likes other motors, but just won't work well with this one. So, he is changing out to another speed control and that will most likely do the trick.
I have a motor/esc combo that does a rough start (on a gear box none-the-less) so I've learned how to blip the throttle just right to get it going and I just set the idle trim up to a very low idle so I don't have issues in flight.

goldguy

Try a smaller prop and see what happens. Too large a prop will cause it to shutter on start-up.

davidm

My Feedback: (18)

I am running a Ultrafly Model D/13/32 Outrunner Brushless Motor on a F-16 pusher, gear drive.
It has a sputter problem at 80-100% on the power. I have a 25a silver series controller and 3s lipo.
Any idea what would cause the spudder/ cutting issue?

Thanks
Davidm

pilotpete2

David,
You did not mention how many amps you are drawing at WOT, if you don't know the answer, that's probably your problem
Regards,
Pete

davidm

My Feedback: (18)

Your right, I do not have a amp meter, should I try a smaller prop as a easy fix?

DavidM

pilotpete2

David,
You could try a lower pitch prop, or one size smaller in diameter, but in the long run an E-Calc type program and a WATT METER are your best bet.
Regards,
Pete

Troy-RCU

My Feedback: (1)

That sounds like you are hitting low voltage from pulling too many amps. Your esc is designed to pulse when you hit a certain voltage. The amp draw may pull hard on your 3-cell lipo and drop the voltage to the point you are hitting the low voltage. Try a smaller prop....

davidm

My Feedback: (18)

Thanks for the replys, I did install a prop 1 inch smaller and it is better. I have not flown it yet, just static running. Wondering if the 25A controller could be dragging it down. The sheet with the motor did not specify what size to use, I went by what Tower had on the item list.

DavidM

Troy-RCU

My Feedback: (1)

Well, it's a little more complicated than just an esc issue. You could be pulling too many amps on you Lipo battery if you are hitting the low voltage safety of the esc. The fact that your Lipo's voltage under load is dumping to the LVC (low voltage cutoff) means your battery is having a problem withstanding the demand of the motor and prop. On the other hand, if you are pulling tons of amps and it's over the recommended 25amp max specs of the controller, you can risk frying the esc, too. My suggestion is to find a way to figure out how many amps you are pulling on this set up.
The best $50 I spent on a tool was a Sears Clamp meter:
[link=http://www.sears.com/sr/javasr/product.do?vertical=TOOL&bidsite=&pid=03482062000&BV_UseBVCookie=Yes&subcat=Multi-Meters,%20Testers%20&%20Accessories]clamp meter[/link]

davidm

My Feedback: (18)

I see Hobbico has a meter for $39.99. The paper work with the motor only shows the watts, no amps.

Thanks
David

gunracer

you can kinda guess the amps from the watts...i don't recall off hand what voltages 2s and 3s batts generally stabilize at under load...but i would use those as starting points to deduce amp figures from the motor's watt rating...

Troy-RCU

My Feedback: (1)

Well watts fluctuate depending on the battery and prop so the watts posted on the motor are there as a target that you don't want to exceed. A 300 watt motor means it can take a continuous 300 watts of power and won't over heat on you. You can go over for brief periods of time but the average for the flight needs to be closer to 300 watts.

If you are planning on sticking with e-power for a while, I highly suggest getting a watt-meter or at least an amp meter. They are coming out with a lot of nice little units like the E-flight one here: $44.99
I didn't see a Hobbico one available. The clamp on one I have is nice because I typically measure upward of 100-120 amps and the in-line type meters robs a little power from the equation (at those power levels) and the clamp meter is passive. I have to manually calculate watts but it's pretty simple.

pilotpete2

Watt are you flying[X(] a full scale motor sailplane??? That's some serious power[8D]
Regards,
Pete

Troy-RCU

My Feedback: (1)

No, a bit smaller and faster
http://media.putfile.com/Troys-D-99