T.W.

Hi Guys,

I've got a really irritating glitch problem with my electric-powerd model and wonder if anyone could advise me how to fix it

The model is an EasyStar, into which I've cut ailerons. It has a brushless motor and uses LiPo batteries (3.5mm gold bullet-type connectors) and has a LiPoSaver fitted. I fly it on my Futaba 9CP Super and so-far I've checked-out the RC gear and it all seems fine. I've tried two different Rx's, a GWS 8-channel and a Schultz 4-channel. I've tried wrapping the Rx with cooking foil, shortened all the cables, installed the ESC as far from the Rx as I can, but still the glitch persists

The glitch happens anywhere from around 100ft away, to as far away from the Tx as I can see the model (maybe 1,500ft) and anywhere inbetween. Mostly it happens when the Tx aerial and the Rx aerial are 'aligned' - but not always. Range-checks prove the radio works fine, and I can fly the model 'till it's a dot in the sky and still be in control

The glitches only happen when the throttle is at more than 1/4. At anything less than 1/4 throttle the glitch never happens. Most times the glitch is in the form of the motor simply 'missing a beat' or two, occasionally the model will 'twitch' one way or the other - and just once in a while the glitch is very severe with the model almost rolling inverted - but quickly!

The glitch just won't show-up on the bench. I've had the motor running at full-power and it sounds as sweet as a nut, yet every time I give her full power with the model in the air that glitch is always there. It's got me beat

So: has anyone had a similar problem to this? Do you have any idea what might be causing it?

I think I may have a problem with the motor, ESC, or cables - but without being able to replicate the problem on the bench I don't know what to try next

Any advice would be welcome

Tony

OEMFlyer

T.W.
Without knowing what esc or motor you are using my guess would be that since you added one or two servos for the ailerons you may be overloading the bec on your esc.-Just a thought-OEMfyer

DaveFlynn

All it takes is one bad servo feeding noise back into the receiver and the whole system gets flakey. I eventually traced my similar problem back to a cracked capacitor in one of the servos.

T.W.

Thanks guys

All the RC gear was bought with the sole intention of fitting the ailerons, so I'm not overloading anything

The servos have worked perfectly during all bench-tests - but I don't know if this means they can or can't be faulty in some way. I can't check this out on the bench either as the glitch has never happened during bench-tests

I'm wondering if I have a problem with the motor, ESC, or cables - but without being able to replicate the problem on the bench I don't know what to look for nor what to do next, so am really looking for advice from anyone who's had a very similar problem. I don't want to start cutting-up the model in order to extract all the gear unless absolutely necessary . . . . hmmmm, I could change the servos easy-enough though. Think I'll do this first and see what happens

Tony

T.W.

Just a thought before I start cutting my servos free: If the glitch 'is' being caused by a faulty servo, wouldn't it glitch when the model was gliding and using less than 1/4 throttle? What I've noticed is that the glitch only happens when the throttle is open more than 1/4

Tony

whitecrest

Perhaps you are getting local radio interference at your flying field. Some fliers have had problems flying in ball fields near tall metal lighting towers which can reflect radio waves causing interference areas in a flying field. It might be worth seeing if you get the same glitches at a different field. Your bench tests seem to rule out faulty electronics. Good luck with your trouble shooting.

cyclops2

Do the same outdoor range tests with ONLY the motor lead disconnected. Have everything else running. Move the joysticks & throttle stick just like you normally do.
Problem there ? We know it should be a ESC, BEC, 1 or more bad servos.

No problems.

Or your power wires are too close to something, hot ESC.
I have stuffed all the Battery, ESC, receiver and servos on top of 1 another & had no problems.
Other planes needed to have power stuff WAY AWAY from all else.

Q C problems ??? bad news if so. Bad or loose receiver crystal in the holder? There are some nasty problems that can only be found by substituting good parts 1 at a time.

I have spent almost a hour on a bad HITEC FEATHER LITE receiver with a interrmittant servo connector that had a cracked pin on the PC board. [:@]

T.W.

Thanks for your help guys

Whitecrest: I don't think it's local interference because I've flown many other models at this site without any problems whatsoever

Cyclops2: With the motor lead disconnected there's no sign of glitches. In fact there are no glitches when gliding or flying at less than 1/4 throttle either - only when I open the throttle (I'm starting to think I need to change the ESC)

You may be right about this: ". . . your power wires are too close to something, hot ESC," so I'll move things around (not for the first time) before changing the ESC

There's definitely nothing wrong with the Rx/Xtal as I first changed the Xtal and later swapped the Rx, using yet another Xtal - the glitches still happened

As I said: I'm now almost (but not quite) convinced that the ESC is causing my problems - that or a bad connection between it and the motor. Looks like I need to start pulling the model apart . . . again!

Tony

cyclops2

I would go for the ESC. ORRRR. Even a JUST STARTING to becomes loose. Loose power connection.
I have ALWAYS cutoff ALL pretty heatshrink tubing on motors & ESC's. Found loose crimped or not soldered well enough connectors. Check that first . Tell me with what you find.


Check the battery leads the same way.

cyclops2

Check the battery connectors also.

T.W.

I still haven't done anything yet, except 'think' what to do! So I will check the motor connections first - that's a great idea actually

I doubt it will be the battery or the ESC plugs/sockets, as I fitted them myself (ha ha! of course it could be them! I need to re-check don't i! )

You're right about everything you said really. I've been looking for a clue as to what might be causing the problem in order that I don't have to completely dismantle the model. But it's just not going to happen this way is it. What I now realise is that I have to start by removing the motor and checking that, and then work my way through the electronics removing the next part to examine it only when I find nothing wrong with the previous one. Maybe this way I'll find the fault before I've chopped the whole model apart to get at the parts!

Oh well, I'd better get started. Thanks for this

Tony

cyclops2

Why did you make the installation so permanate ? I tape & use chunks of soft and hard foam on the fist few solos.

Rich

DaveFlynn

Sounds like the ESC may be putting out some noise that is shortening the Rx range. Try a different Rx, I have been using the Berg 7 Rx's with no problems at all. I sold off both of my Electron 6 Rx's as they seemed to have a problem with the CC HV-45 ESC at anything over 400 to 500 watts.

T.W.

Rich: Don't know - maybe I'm stupid, but I sort-of expected everything to work ok. I've now managed to get everything out without destroying the model though. I can't see into the motor (Turnigy B2835-2700) - does it come-apart so that I can inspect the connections inside? How?

The rest of the connections seem to be ok. Tried 'wiggling' all connections with the motor running - no problems

I've already tried different Rx's and Xtals Dave. My Schultz counted 6 glitches during the last flight - it would have been a lot more had I kept the throttle open!

Looking at the the cables now that I've pulled them all out, I can see a couple I could shorten - which I originally extended so they'd reach the Rx (then I had to move the Rx elsewhere and that's why they're now a bit too long)

I think I'll shorten as many cables as possible, and maybe mount the ESC on the outside of the fuz, on the side. Perhaps I'll then be able to get a bit more space between the power cables and the Rx cables . . . . tomorrow

Tony

T.W.

Can anyone tell me how I can get into my Turnigy B2835-2700 motor?

I want to check the connections, but they're inside the can and I don't know how to open it (and I don't want to ruin it either!)

Tony

cyclops2

Leave the motor alone........Just connect a DIFFERENT motor and prop of the same power level.

Jury rig it with a C clamp or vise or even electrical tape. That will safely eliminate the motor as a problem. Run it at the bad distances.

Can you just substitute the receiver with another an run it at the BAD distances?

My gut feeling is a component is intermittant. Problem is, both the servos & the motor are affected? Yes or no.
I usually only get 1 or the other. Bad battery? swap check at bad distances.
ESC? Swap.


Holy cow!.....Had this 1 time, similar problem Bad / wrong transmitter crystal. Change transmitters. Check freq. different trans. & crystal & battery pack...........Had a bad transmitter voltmeter. read good, but power was nothing.
If you have a helper to hold the plane at bad distance. you can check each transmitter.

T.W.

cyclops2: Thanks for your advice

I fly lots of different models using the same Tx, and my EasyStar is the only glitcher, so it's nothing to do with the Tx

I've now had two different receivers and four different Rx Xtals fitted to the model - with exactly the same 'glitchery'

The 'clitch' happens with all five batteries I use with this model

Why I want to get into the motor: To check the connections between the windings and the cables - they connect-up inside the can so I really need to gain access. I want to check these connections because I've been advised this could be where the problem is - and I believe it could be too, because I had a dry joint on one of the motor connections when I converted my Ikarus Piccolo to brushless some years ago - and the 'glitching' was exactly the same, ie: the motor sporadically misses a beat or two at high throttle settings

When I first flew my EasyStar the control surfaces glitched as well as the motor, but I've fixed the control surface problem (found an almost severed servo signal cable - I must have almost cut it through whilst hollowing-out the inside of the model after installing the servo - maybe)

Now it's only the motor that 'skips a beat' or two when I use anything more than around half-throttle


Tony

ray foley

hi there from Toledo

Go to rcg and search for a discussion that I hosted called "to choke or not to choke, that is the question."

The info there will help you immensely. The info is directed at systems on 72mhz. The choke issue does not apply to 2.4ghz systems, so I am told. So the Guys with the newer systems can't relate to your issue.

ciao -rjf

T.W.

And Hi from the Uk to you Ray - I'll do as you suggest. Thanks

Tony

Willit Run 353

Try a new motor it may be that the current one is causing problems with the signal.

I have heard that using another make of RX to your Tx is bad. Is this so or do you only have to use the Tx manufactuers crystals. I don't know about this because I only use futaba 2.4 systems

T.W.

Ray: That's an awesome thread you pointed me at. It makes fantastic reading. Only yesterday I fitted a ferrite ring to my model's LipoSaver/Rx cable, close to the Rx (still awaiting suitable flying weather to test-fly btw), so I was even more interested - as you obviously knew I would be!

I have a question for you. Can you tell me anything about the installation system shown in this pic (lifted from your thread). Does this work better than the normal method?

Tony

T.W.

Well it took a heck of a long time to discover what was causing this particular problem - but I got there in the end!

One afternoon I was flying my model, with the motor 'skipping a beat' every now and then,' as usual. When, during the second flight of the afternoon, the motor stopped completely. After landing the model I discovered that one of the motor's three power cables had completely 'let go.' It took me a little while to find the break, as it was still hiding inside the cable's external layer of insulation

In order to get a few more flights in I temporarily re-joined the cable using an old electrical connector which I found in the bottom of my toolbox, and although this looked very agricultural, it made a world of difference. The motor's stutter had now completely vanished - and there was also more available power too!

The temporary repair was made permanent later, and the model continues to perform well - 'sans stutter'

Tony

ray foley

hi there from Toledo!

Sorry for the long delay in returning your question. Also I liked the agricultural temporary fix, bravo! The photo was just a possible way of winding the toroid to get more turns on the same core. Most folks recommend 3 turns minimum. Well this has more than 3 but it did require disassembly of the servo connector and some creative stitchery. I have no good way of testing the setup except to say that it has worked well for several years in a plane that had some nasty ESC / rcvr noise issues. Thanks for the interest

ciao -rjf

T.W.

Hi Ray,

Thanks for getting back to me on this. As you probably read above, all the glitching and stuttering turned-out to have been caused by a broken motor power-supply cable - which at the time seemed odd, as I didn't know why the cable had broken . . . however, after thinking things through, I decided that it might have been because I (once) fired-up the motor without having thought to glue it into it's nacelle . . . . it twisted the cables a little

The workshop repair seemed to work just as well as my temporary flying-field-fix, and flying continued perfectly from then-on

So, everything was fine, until (by a very strange coincidence) just today, when I heard the motor stutter just before it cut-out and refused to start-up again. Checking the motor's cables I discovered that the very same cable has again broken (see pic)

Here you can see where my previous repair invoved soldering a thicker length of cable into the connector to give me something to solder the broken cable to. And perhaps you can also see that the original cable has now broken even further away from the connector than the previous break

I don't understand why this cable has broken yet again, as there's nothing 'pulling' at it or trying to twist it. The repair was again easy to effect, but I'm at a loss as to why this cable has now broken twice

Tony