tx, rx, or ESC problem?

[Big Daddy]

I think I have it narrowed down but I figured I ask those of you who know more than me.

I have the AX-2, AR-2, AE-2 combo. The issue is the truck will take off on it's own or when cruising along it will surge or when starting out it will go WOT when you just crack it open a bit.

At first it sounds like an ESC issue but, some of the circumstances surrounding it make me think it's a tx issue. If I wiggle the remote or tap the side I can get some input into the truck. Sometimes if I toggle the steering back and forth I can get the throttle to react also. A quick blip of the throttle usually calms it back down from whatever it is doing but that can get me into trouble in some cases like when I was driving on rocks right next to the lake.

What I have done so for is, recalibrate the ESC, re-bind the radio, replace all batteries. I also disassembled the radio and all the solder joints looked good as far as I could tell. But I'm not an expert by any means. I am thinking the throttle is hosed in the remote, but I am interested in any other ideas as well.

Thanks,
Kevin

[Charlie-III]

Not knowing your radio, is it 2.4ghz or an AM/FM radio??
2.4ghz is sorta immune from radio interference, AM/FM can be glitched by outside interference.

Making sure you have CORRECTLY calibrated the ESC to the RX helps, but AM/FM can also screw things up.

[SMR 510RR]

Here is what you do...

Take two servos and plug them into the steering and throttle channels, it helps if they arent attached to anything except a servo horn. Now plug whatever is powering your RX into another slot, either a BEC or your esc. Now act like you are driving and keep an eye for any strange movement of the two servos, this should help you narrow down your problem. If there is strange stuff going on then you know it is a TX/RX problem, if they are acting normal then you can be almost positive that your radio gear is ok. That being said, you could still have some interference problems so dont rule them out completely.

[Big Daddy]

The AX-2 is a 2.4 system. I followed Axial's instructions for calibration and to bind the TX/RX.

I'll have to pull a servo out of my touring car to do that test.

I'm considering getting a DX3E and going from there, good excuse to get a winch too

[SMR 510RR]

Originally Posted by Big Daddy

The AX-2 is a 2.4 system. I followed Axial's instructions for calibration and to bind the TX/RX.

I'll have to pull a servo out of my touring car to do that test.

I'm considering getting a DX3E and going from there, good excuse to get a winch too

Check out the GTB3 hack thread. Very good way to go for a great radio system on a budget.

[Trubble]

Originally Posted by Big Daddy

If I wiggle the remote or tap the side I can get some input into the truck. Sometimes if I toggle the steering back and forth I can get the throttle to react also. A quick blip of the throttle usually calms it back down from whatever it is doing but that can get me into trouble in some cases like when I was driving on rocks right next to the lake.

Sounds to me like a dirty and/or faulty throttle pot in the transmitter. A quick blip of the throttle probably works by dislodging whatever's caught inside that pot and possibly shorting your contacts inside. I doubt you'd see that from the outside, and your solder joints (on the outside) would look completely normal. To be honest, it would only take just the smallest filing of metal from who knows where to wreak that kind of havok, so I doubt even if you disassembled it, you'd catch what was doing it. Testing for an intermittent problem like that could be pretty tough, unless you could get said object to cause the problem reliably.
On the other hand, finding a dirty or dead spot wouldn't be hard to find, as it'd be there consistently, and would always occur at the same throttle position. There, too, blipping the throttle would use friction to sweep away any carbon tracking and expose the contacts in the pot that are needed at that throttle setting.

First test I'd run is the servo test SMR mentioned. (primarily because I have nearly a dozen spare servos lying around), to see if you can find the glitch and see if it occurs at a particular position. Then, not sure if/how you can check the pot with a VOM, but I think before I bought an ocilliscope (sp?) to check that, I'd look at new radio gear. You could just completely gamble on a shot in the dark and just replace the pot, maybe get lucky and that'd be it.






Or you could just start radio shopping...........

[Big Daddy]

Well I think I narrowed it down to a bad throttle switch on the TX. I plugged in my Honcho ESC to my touring car and the throttle reacted as you would expect. Then I plugged the touring car ESC into the Honcho RX and it glitched in there. The easy answer would be to use my old Futaba Mag Junior, but I really don't want to go back to AM.
So I'm thinking either pick up one of the many wraith take offs out there or a DX3S. The only reason I really want a 3 ch is so if I add a winch in the future it will control in/out feed.

[SMR 510RR]

Originally Posted by Big Daddy

Well I think I narrowed it down to a bad throttle switch on the TX. I plugged in my Honcho ESC to my touring car and the throttle reacted as you would expect. Then I plugged the touring car ESC into the Honcho RX and it glitched in there. The easy answer would be to use my old Futaba Mag Junior, but I really don't want to go back to AM.
So I'm thinking either pick up one of the many wraith take offs out there or a DX3S. The only reason I really want a 3 ch is so if I add a winch in the future it will control in/out feed.

Dont get a dx3s then...It only has a 2 position 3rd channel so it will not control a winch. Check out the GT3b with the hack from losikid.

[Big Daddy]

That was a typo actually it was supposed to be DX3E. I haven't looked into FS radios yet. But I'll read up on them. THX

[Grumpster1980]

Contact Axial and get a free replacement. It should be under warranty still.


If your looking for a new TX/RX combo I have been thinking about this one .....

http://www.hobbypartz.com/79p-gt3b-carradio-lcd.html it's been getting great reviews but who knows.

[korn_2956]

that flysky radio looks like it would be a sweet radio but i couldnt find if it has a 3rd channel on the tx and if its a 3 position or what.

[IceBox84]

I have the FlySky RX/TX and love it! No more 200+ dollar radio systems for me.

It is a 3ch radio, if you get the hack done by losikid like smr said then you will be able to run a winch. I use my 3rd channel to operate my lights. Look into it, if they are still in stock act quickly because they are known to go FAST!

[SMR 510RR]

Originally Posted by IceBox84

I have the FlySky RX/TX and love it! No more 200+ dollar radio systems for me.

It is a 3ch radio, if you get the hack done by losikid like smr said then you will be able to run a winch. I use my 3rd channel to operate my lights. Look into it, if they are still in stock act quickly because they are known to go FAST!

Exactly plus after the hack you can have up to 8 channels! That means you could have a bunch of lights (with on off control) a couple winches and still have channels left over.

[korn_2956]

so no 3 position for dig then