propjobbill

I am new to electric, I have bought 3 speed controls they are rated at 15 amps or more, 2 of them have reset switch on them and the third one doesn't. The one without the reset bottom works fine. The other two speed controls work great as long as I don't give the plane to much throttle, if I open them up full speed they shut down. I can reset the switch and it starts back up but if I give it full power it shuts down. I even went to a 4.8 volt pack same thing.

Can anyone tell me what is wrong?

THANKS Bill

Matt Kirsch

My Feedback: (21)

That's not really enough information to diagnose the problem. What battery, motor, gearbox, and prop are you using on each of these? What brand is each of these ESCs?

An ESC mysteriously "kicking out" generally means one of two things:
1. The battery can't take the Amps, so its voltage is dropping and the low-voltage cutoff is kicking in.
2. The ESC is carrying too much current, and it's overcurrent protection (if so equipped) is kicking in.

Binding in the drive train, too large a prop, or too many cells will cause excessive current to be drawn. Using poor quality cells, damaged cells, or cells that are too small will cause drastic voltage drops.

propjobbill

I am using a 280 size motor with a GWS 6-3 Prop, an AAA NIMH cells some times 6 or 8 cells the results are the same. Maybe the batteries are the problem. I have a 6 cell battery made for RC, Iwill charge it up and see if that makes a difference. Thanks for the help I will let you know what happens in a day or so.

Thanks Bill

Mikerjf

I even went to a 4.8 volt pack same thing.


You're using esc's on 3 and 4 cell packs? Don't know of many that work on less than 5 or 6.

Mike

propjobbill

I tried them with the RC battery pack made for RC 1500mh 6 cell and got the same results. The engine will start as I increase the speed to full power it cuts off. It does appear that so long as I keep it at 1/2 to 3/4 power it will run. It acts like something is causing it to shut off so I guess it’s doing its job the battery has lots of power so it's not low voltage from a weak battery. I have even thought about buying an auto shutoff and running two battery packs one for the motor one for the radio, but I really don’t want the extra weight.

I have used motocalc and it’s says everything should work fine. But what is being said on paper and what is really happening are two different stories.

I tied to get into Electric this spring, but even with the good speed controller it seamed like it would shut down after about 1 minute or less. If I bypass the speed control and hook up to the battery direct it runs for a long time.

I do know that when I used the 4 pack it was probable shutting down because of not enough voltage, but thats not the case the 7.2 or the 9.6 volt packs

I know it must be something I don't understand, I have bought 4 different speed controls from different manufactures all rated for 15amp and one 20 amps. I have tried 280 speed and 400 speed motors both direct drive and with gearboxes with the same results. I’m spending a lot a money on these electric to never be able to get one flight out of them with Glow engines you fuel them fire them up fly and repeat. I think I would really love to fly electric. But it seams like I am doomed to fail at Electric. I am a determined person and I will keep trying. Any help or suggestion will be appreciated.



Thanks Bill

Matt Kirsch

My Feedback: (21)

But it IS the case with the bigger packs. When you draw more Amps than a battery pack can sustain, the voltage drops, and drops, and drops until it gets so low that the low-voltage cutoff kicks in.

Measuring a battery's voltage with no load is meaningless. NiCd and NiMH will show full voltage until they're nearly completely drained.

Hold a voltmeter on the motor's terminals, and try a run. You'll probably see the voltage start out pretty high, then drop quickly until the motor cuts off.

Either your motors are drawing excessive current due to too much prop, binding, etc., or your batteries are insufficient to handle the load.

Beware that the "calc" programs just give you numbers. They don't tell you if a combination will work or not. You have to interpret the numbers. For example:

I just ran your Speed 280 combo through P-Calc at www.flydma.com. It should draw around 4.5 Amps. GOOD AAA cells like Sanyo 720mAh will handle up to 6 Amps, but 4.5 Amps will be too much for el-cheapo cells. On a Speed 400, forget about it. AAA cells are not good enough to handle the 10-12 Amps a typical Speed 400 setup will draw.

This "RC 1500" pack... It wouldn't happen to be an old car pack from your R/C buggy days way back when, would it? You can't trust the condition of cells that have been sitting around for a long time, especially cheap R/C car packs that have been subjected to the abuse of bombing around in a buggy.

Mikerjf

Another possibility is the connectors making poor contact. If they're Tamiyas, crimp the female ends.

Mike

propjobbill

Hi Matt,

I did a voltage test across the motor terminals it only reads 4.15 volts. I don't have the paper work on the controllers but I do know many of these are set at less than 5 Volts. So would it be fair to say that the voltage is too low, which you say is because the batteries are not adequate for this application?

Thanks Bill

I Checked It out with another RC battery pack and the batteries were the problem. THANKS FOR ALL THE HELP

Matt Kirsch

My Feedback: (21)

Yep, I figured someone sold you crap batteries

Glad to see you got it figured out.

For the 280 motor, I recommend KAN650 or CBP650 cells from cheapbatterypacks.com
For the 400 motor, I recommend KAN1050 or CBP1050 cells from cheapbatterypacks.com

propjobbill

WOW! THANKS Matt for all the information, and for the website, cheapbatterypacks.com, they have great prices. Just wish I would have know all this a year ago. I would have been flying electric all summer.

THANKS Bill