I am switching over to electric flight and have a great planes ultimate biplane with a electrifly 35-30-1250 outrunner , ss-35 esc and futaba electronics. The receiver is a 4 channel and on it it specifies that channel 4 is battery (esc wire). Well I connect it as stated and that channel 4 controls the motor the only deal is it uses the rudder on my remote and not the throttle portion of it while the throttle portion activates the rudder. everthing else is ok. Now if I hook up the battery wire to the channel 3 everything acts as it should. Does it hurt it to hook the battery up to channel 3? any ideas on what is going on?

jeremy,

thats the way it should work, esc hooks to channel 3 or throttle channel on the RX.



bassman

jeremy,

Mose ESCs have in them what's called a BEC (Battery Eliminator Circuit) which allows the flight battery to supply voltage to both the motor and receiver, so no receiver battery is needed.

The 'battery wire' coming from the ESC is dual purpose...

First, it supplies voltage to the receiver and servos just as a receiver battery would.
Second, it sends the throttle signal from the receiver to the ESC.

So, the only connection you need is from the ESC to the throttle channel of your receiver, which in your case, is channel 3.

Thanks for clearing that up.

Just in addition: Usually you have to reverse the throttle-channel on Futaba transmitters for most ESC`s.

The thottle is going the correct way. I just cant figure out why it is cutting out.

First, since you are engaged in electric flight, Be sure to read the e-book on electric flight
http://www.rcuniverse.com/forum/m_7100376/tm.htm

Now, what is cutting out?

Thanks for your reply, my motor is cutting off after running for just a few seconds. If I run it up to full power it seems like it just keeps getting slower ( guessing by about 100rpm) then it will shut off. Usually when I cut the throttle off the prop woud slow down gradually then stop like it shoud but know when I cut the throttle it stops very abruptly like the esc on the brake is on but it isnt. Any ideas? Thanks in advance for your help. Jeremy

Ok so after I posted I was messing around with the plane and the brake was on on the ESC so I got that fixed but I noticed I ran it for about 20 seconds at 3/4 throttle and it shut off by itself. I can reduce the throttle all the way to stop then advance it and it will go again for a few seconds then stop again. When I stopped it the motor is extremly hot after that brief run. It has sufficent air going through the motor I know because I have a blow gun ran off of my air compressor blowing on it to keep it cool. The esc wasnt hot either so I am confused. I am starting to think I made a bad decision with going to electric from nitro as I havent flown in 2 months from dealing with this issue. Thanks for your help.

Oh and I read your post on electrics and it cleared up alot of questions I had , Thanks.

Jeremy, if this is your first electric there is a learning curve involved.

It sounds like your motor is drawing a lot more current than it should based on the fact that you say the motor gets hot. Also, it sounds like your ESC is reaching LVC since you can regain motor control after bringing the throttle back to zero which resets the LVC.

Do you have a wattmeter?

This is the single most important piece of test equipment for electric flight. Successful e-fligh is based on the proper combination of motor, ESC, and prop. Your motor and ESC have specific current ratings which shouldn't be exceeded which easily can be done with an incorrect prop.

Don't give up on e-flight too quickly. At least you have the flying experience. Just think of all us newb's just getting into e-flight with no electronic or flying experience...

Just hang in there, my man... You'll eventually get it all together.

No I dont have a watt meter. I was going to get one but I figured since I was using all of the recomendations from greatplanes everything would work as it is supposed to. Should I buy one? I am also using there recomended prop for this set up. Thanks for your help, Jeremy

Although you're using the recommendations from greatplanes things can still go wrong. The only way to know for sure is with a wattmeter, or at least a Multimeter capable of measuring amperage equal to or greater than the expected current draw of your plane.

If you don't mind, could you list again everything you have?

Plane:
Motor: (please indicate maximum allowed current draw just in case we can't find it on the web)
ESC: (please indicate maximum allowed current)
Prop: (size and pitch, manufacturer, if known, and type of prop, ie; Slow Fly, Direct Drive, Thin Electric, etc.)
Battery: (volts or number of cells, capacity in mAh, "C" rating)

Sorry to ask for this information again, but it will be a great help to have all the information in one place rather than having to search the entire thread to put it all together.

Thanks

Great Planes ElectriFly E-Performance Ultimate Bipe.

ElectriFly Silver Series 35 amp Brushless Electronic Speed Control-
Input Voltage: 6-12 cells NiCd/NiMH
2-4 cells LiPo
(20V input w/o BEC)
Output Current: 35A continuous maximum
40A surge maximum
Max Output Power: 350 watts
ON-resistance: .01 ohms
Operating frequency: 8.5kHz
BEC: 5V/2A
Low Voltage Cutoff: Battery voltage x .67
Thermal Cutoff: 230°F (110°C)
Timing Angle: 12°
Brake: ON/OFF

GreatPlanes ElectriFly RimFire 35-30-1250 Brushless Outrunner Electric Motor.
Max. Constant Current: 30A
Max. Surge Current: 35A
Max. Constant Watts: 333W
Max. Surge Watts: 390W
No Load Current: 1.2A
Input Voltage: 11.1V
RPM/V (kV Rating): 1250
Weight: 2.5oz (71g)

Great Planes ElectriFly Power Series
Lithium Polymer 2100mAh 11.1V 20C Battery Pack with Balance Connector

10x7 Slo-Flyer "tractor"

I got my wife to stop by the LHS and pick up a E-Flite Watt meter on the way home from work today. I was going to check to see what the plane was pulling but I didnt get her to get my deans plugs for it. Oh well I guess it will be Wednesday before I can get them. I really appreciate all of the help

Getting the wattmeter is good.

When you start your test, watch the amperage and voltage of the battery as you run up your motor. As the motor spins up you should see the amperage increase and the voltage decrease. Make sure the amperage doesn't exceed the rating of either the motor or ESC. Also, watch the voltage and see if you can determine what it is when the LVC shuts the motor down. I think the wattmeter has some sort of memory for high and low readings, but I'm not sure. I don't have a wattmeter, I use a DMM, but it has these memory readings.

Post back your findings.

Well I ran the test and the LVC is not shutting it down because the Volts is still at 11.1v. when I started the motor and ran to full power the amperage started at 34.2 AMPS and started falling without me moving the throttle. It fell to 33.0 then I switched the mode to view the voltage which was still above 11 When I switched back to amps the the amperage had risen and spiked at about 40.5 then it shut itself down. I brought the throttle all the way back and tried advancing it again and all it would do is sit and studder for a couple seconds then shut off. My ESC is pretty warm (will not burn you but its heating up) to the touch and the motor is getting hot also. Is the amperage supposed to start falling like that while running? Thanks in advance for the help.

You are pushing the ESC and motor at 30 amps or more. Definitely not good at 35 and over.

Try proping down some, say, to a 10x4.7 or even a 9x4.7. You've got to get some of the load off the motor.

Sir R has it about right. Let me summarize my guess;

1) you have a 35 amp ESC ( 40 surge ). You are running over 40 amps at some points. So you are probably inducing a thermal shut down in the ESC.

2) You say your ESC Max Output Power: 350 watts for the ESC, according to your listing. For your motor Max. Constant Current: 30A
Max. Surge Current: 35A Max. Constant Watts: 333W Max. Surge Watts: 390W. But you are pushing over 40 amps at 11 V, so that would be 440 watts. Again, very possible you are over heating the motor or the ESC.

3) The brake feature of the ESC has no bearing on any of this. The brake only works when you shut the throttle off. It stops the propeller from freespinning. It can not be involved in this issue.


4) You have a 2100 MAH 20C pack. That would max out at 42 amps if you push the pack to the very limit. Sounds like you are doing that too.


So you have an ESC being over run, a motor being over run and a battery pack right on the edge.

Yes, I would say you need to prop down. You are running the recommended prop, but you are drawing too much power.

Is it possible the motor can is rubbing against something in the plane?

Thanks to the both of you for a quick response. The can is not rubbing anything in the plane so I will get a couple different props for it and go from there.

Thanks again, Jeremy