Flysfloats

No good deed goes unpunished!!!! I recently got a friend of mine down here in Baja interested in r/c flying as a hobby. We ordered a Hobby King arf, a BFG 1600 electric powered sailplane. When it finally made it down here we eagerly put it together and had to change a connector plug for the battery to the installed motor. The plane came with servos, 20 amp esc, a folding prop and motor. Additionally there is a pylon mounted motor but we elected to use the folding prop motor. Everything checked out fine on the initial functional check.

I had donated my old Cirrus Wave 5 transmitter and a Futaba receiver. Next day that we had with no wind I drove the 30 minutes to his house and got ready for his initial flight. Bummer, "we" had left the transmitter on and the battery was dead. So, I took my Fun Cub and we flew it numerous with me taking off and landing and letting my friend fly race tracks and circles in the sky with me grabbing the transmitter at the first sign of trouble. So far so good.

Today, a week or so later, we had lesson #2. When I got there he was grumping around saying something about the control surfaces going bonkers after running the motor at half throttle??? Being the semi blind leading the blind I investigate. With the motor not running, ailerons, elevator, and rudder performed normally. I then increased the throttle to full and still no problem, I then varied the throttle setting and soon the control surfaces were pulsing at will, impossible to control them and it seemed like the motor wasn't running smooth.

I pulled the cowling and looked at things and all looked fine. I pulled the esc out and it was very hot to the touch, hmmmm. The way I connected the wiring to the receiver was, what I though was conventional: #1 port got the aileron servo, #2 got the elevator servo, #3 got the esc wiring, #4 got the rudder servo. NOW, this receiver has a "B" port where the normal receiver battery would be plugged into, so this was empty.

My question to you is what am I doing wrong?? I only "assume" that the 11.1 volts from the battery "may" be going into the esc and the esc is failing to reduce voltage for the servos to 4.5+/- like a receiver battery???

Is it possible or likely that the provided esc is not a bec and that is my problem?? Sorry to ask this basic of a question but electric power is still somewhat new to me. It is times like this I miss my old glow engines!

Thanks for some helpful comments. FF

CHELLIE

Hi Are you on 2.4 or 72 Mhz, Most 72 Mhz Receivers dont like E Power, to much RFI for them, I use Berg Receivers on 72 Mhz because they have the best RF filtering, Hitec receivers have been good to use on E Power too, Also does your ESC have good airflow going to it, use a ESC thats 20 to 25% Bigger than whats needed, it will stay cooler and Last Longer, I like the Turnigy Plush ESC, they have been Bullet proof for me, Hope that helps, Happy New Years, Chellie

http://www.hobbyking.com/hobbyking/s...ontroller.html

http://www.hobbyking.com/hobbyking/s...ontroller.html

xmech2k

Hi FF. If your ESC is getting so hot, it may be the BEC inside is failing to supply enough power to the radio system. Is it a 72mhz or 2.4G? 2.4G is known for low voltage brownouts, but I understand 72mhz systems are less susceptible. I had very little 72 experience though. Maybe see if a separate power supply for the rx/servos will help. But if the ESC is getting hot enough to cause that kind of trouble, I recommend getting a wattmeter and making sure you're not exceeding it's rating. My thoughts anyway. Hopefully some smarter folks will come by with some ideas. Good luck!

Edit: Chellie beat me to the enter key!

xmech2k

Chellie has a good point. Make sure the rx antennae is clear of other wiring, metal things, etc.

CHELLIE

Flysfloats

Thank you all for the quick reply. Yes, the transmitter and receiver I gave my friend is a72 mhz system. It was our intent to give my friend a taste of this hobby at the lowest entry price, therefore, a free transmitter and receiver.

What I can do is swap out the receiver, and use my Aurora 9 and see if that cures the problem. I had the 72 mhz antenna running down the outside of the fuselage so that should not have been a factor.

Will report results in a day or so, after the hangover. Happy New Years, FF

xmech2k

Lol Chellie! I hope that didn't come out wrong. You're one of the smart people I was hoping would give advice.

CHELLIE

Brilliant Minds Think Alike LOL

fhhuber

For 72 mhz we often put a iron "torroid" on the ESC to RX wire to help filter interference. This often cures the issue.

http://www.ebay.com/itm/10-Pcs-22mm-...-/310575813902

(having trouble finding them on Radio Shack site but they have them)

Need one that the plug barely fits through and then wrap the wire through the center 2 to 3 times. Appx 9 to 10 mm inner dia is good. This is a case where close is good enough.

You can use smaller inner dia than 9mm (appx 3/8 inch) but probably have to pull the pins out of the plug, wind the wire then reassemble the plug.

I did a fair amount of flying E-power before brushless and LiPos became available. You CAN solve the interference though it might require a "Glitch Buster" circuit between RX and each servo. The Glitch buster uses an inverter gate IC to double-invert the signal and boost the signal to full RX +/- buss voltage (usually a bit less due to processing in the RX) Trying to remember the IC chip number... when I find it be careful they now make a surface mount micro version that is impossible to hand solder up the circuit.

CHELLIE

When I first got involved with E Power, I had a heck of a time with my planes glitching on 72 Mhz, I used my JR receivers that I used on my Nitro planes and they Glitched like Crazy, I used Torroids on the receiver to esc wires, and it did not help very much, And it caused me to crash a few of my E Power planes, I did not know at the time that E Power puts out a LOT of RFI that Most72 Mhz receivers are not able to filter out, That Caused me to buy a DX6i 2.4 radio system, and no more glitches, but at the time, 2.4 receivers were very expensive, Then I learned About BERG 72Mhz receivers, They worked great with E Power, No More Glitches on 72 Mhz, so I sold My 2.4 Radio system and went back to 72 Mhz, Berg Receivers are the best for E Power, Dont Wast your time trying other 72 Mhz receivers and risk crashing a Plane, Use BERG Receivers with a Berg Crystal, and Problem Solved, Berg Receivers are inexpensive so there is no reason not to buy them and continue to use 72 Mhz, All I use now days is my JR 72 Mhz transmitter and Berg Receivers and have had no Glitch Problems what so Ever, I Like the Berg 4L receiver, use a piece of Tape to help hold the crystal in with, as the crystals are small and can vibrate out, its just cheap insurance to tape crystals in place.

http://www.thefind.com/family/browse-berg-receivers

riverrat

Good advice!
Chellie turned me onto Berg's a few yrs. ago & I have
never regretted it!

Regards
Jimmy

JetPlaneFlyer

Almost undoubtedly it's RF interference causing problems with the 72MHz radio. IMHO with the price that you can pick up cheap 2.4GHz radio gear it's not really worth messing around with 72MHz

For instance can pick up a perfectly decent 6 channel 2.4Ghz Tx and Rx for not a lot more than a single Berg receiver and crystals. If you need more than one receiver for different models then with 2.4Ghz receivers at $10 or less you start saving big time, plus you get all the advantages that 2.4GHz offers.

solentlife

Are we sure its' not the ESC ? the point that makes me ask ...

By time he's pulled cowl .. looked over and then pulled ESC out ... temperature may have dropped back a bit ... possibly it getting over-stressed when used ?

I'd be inclined to plug in another ESC if available first to test before spending out on Rx's and gear ...

Nigel

JetPlaneFlyer

I guess all will become clear when he tries it with his Aurora 9 receiver.
My bet would be on RF interference though. Bear in mind that it was specific to a certain motor speed indicating that it was related to the frequency of the RF being omitted by the ESC and/or motor.

If it's a cheap ESC with a linear BEC (as it's almost certain to be) then it will tend to get hot when testing servos, even with the motor not running.

solentlife

I have plenty of Linear BEC ESC's and they don't get THAT hot .. warm yes. But I have had one or two get HOT and then the motor pulse ... OK - I've never had both BEC and motor fail together - but nothing to say it can't ...

Here's my F15 with ESC that fails and you cleraly hear the 'pulsing' motor and she was a handful to land :



It's only a possibility ...

Pity guy hasn't a Servo Tester to use instead of the Rx to test throttle ....

Nigel

AEAJR

I never flew glow planes. I have only flown electric airplanes, electric micro helis and large gliders. I have flown them all on 27 MHz, 72 MHz and 2.4 GHz. They all worked fine on 72 MHz.

I don't know the Cirrus Wave 5. Is this an AM radio or an FM radio.

Have you ever used that radio with that receiver before?

What brand of crystal do you have in the receiver?



When the ESC is off, or at full throttle is when it produces the least noise. At partial throttle it is turning the motor on and off many times a second and this is what produces interference.

Where is your receiver in reference to your ESC. They should be as far apart as possible, but I have flown 72 MHz in electric airplanes where they have been right next to each other.

How is the antenna routed? Is it fully extended or do you have it coiled up in some way. You should NEVER coil up a 72 MHz antenna unless you do it around a non-conductive material like a soda straw and the wraps can not cross each other.



Your wiring is fine.

Is there airflow into the fuselage to cool the ESC? If there is not it would be reasonable for the ESC to be warm. And if you run it extensively on the ground, even with good openings you will not get as good airflow as you would in the air. Is there an opening in the fuselage to let the hot air out?

The B port is for use when you are using a receiver pack rather than an ESC with a BEC. You have no need to use it.


Your ESC has a BEC or you would be getting absolutely no response from the receiver, servos and motor.

While it is possible the BEC is overheating, since this is the stock set-up I am going to assume that the BEC and ESC are adequate to the task.


Conclusions so far and suggested action items.

Always post a link to the airplane you are discussing. I searched the Hobbyking site and can't find that glider. So I can't review the specs on the plane to see if there could be any hints as to why you are having problems. Please post a link.


It sounds like interference from the ESC is causing problems with the receiver. Do you have another receiver you can try? Even if it is on 2.4 GHz it would help eliminate any question that it is interference with the receiver and the ESC.


As I have no information on the plane I am also assuming that you are using the proper battery voltage for this set-up and have not decided to go up in voltage for more power. If you are supposed to use a 2 cell lipo cell pack and are using a 3 cell pack, that could be your problem.


As you are new to electric flight you might find this useful:

EVERYTHING YOU WANTED TO KNOW ABOUT ELECTRIC POWERED FLIGHT
www.wattflyer.com/forums/showthread.php?t=31368