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T

Toffeenut

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Hi All, Got a funny problem with my Maxx. When I go WOT my failsafe kicks in and hits the brakes, this only happens if I press the trigger hard on my controller, If I hold it just off full on, which on inspection looks like WOT on the truck it doesn't happen.

I have noticed that adjusting my throttle trim down seems to stop it from happening, and vice versa adjusting the throttle trim up makes the failsafe kick in.

Anyone got any ideas why this is, I think it is a mis set needle, and I am guessing the LSN is too lean, but would like confirmation before i start adjusting stuff.

Cheers for anyone who replies.
 
The needles settings probably have very little to do with your Failsafe kicking in. I would say you might have some endpoint issues or failsafe set up issues, and would recommend looking their prior to messing with your engine's needles.
 
ok, Can you explain what "end point issue" are please, this is something I haven't heard of.

thanks
 
End point is a setting within servos. In most servos it is preset at the factory. Some digital servos and others have the ability to be set by the hobbyist. If you have the stock radio, this might not be the issue. I just mentioned it as a possibility.
 
Failsafes engage if voltage is too low or receiver signal is lost. Try checking to see if condition occurs without the engine running (i.e., engine off, apply full throttle and verify the servo swings back to idle + brakes).

-- If it does, then it's either high voltage drop in your throttle servo (bad servo), low battery voltage (check your failsafe instructions for the trip point), or internal circuitry problem with the failsafe (not repairable).
-- If it operates normally without the engine running, then my best guess would be that high frequency vibs are affecting the receiver freq setting causing the receiver to loose a lock on the transmitted signal (could be a bad receiver or crystal).

Hope that's not too confusing.

BassMaster
 
Bass_master1 said:
-- If it does, then it's either high voltage drop in your throttle servo (bad servo), low battery voltage (check your failsafe instructions for the trip point), or internal circuitry problem with the failsafe (not repairable).
-- If it operates normally without the engine running, then my best guess would be that high frequency vibs are affecting the receiver freq setting causing the receiver to loose a lock on the transmitted signal (could be a bad receiver or crystal).

Hope that's not too confusing.

BassMaster
Click to expand...

Does the same thing with the engine off, I have replaced the batteries in both the reciever and transmitter.

I will have a look at my failsafe tonight.

Cheers
 
If it still does it you might try unplugging the throttle servo from the fail safe to determine bad servo, or Rx/crystal problem. Just a guess, I really have no idea, and often get the freakiest radio trouble. Good luck!
 
I'm re-opening this old issue, which I still seem to be having.

As stated in the original post. If my throttle trim is set to center then when I go WOT my failsafe kicks in and hit's the brakes. I have put up with it for a long time now by adjusting the throttle trim down slightly and this seems to stop the problem occuring, but I would dearly like to know what is causing this problem.

Things I have tried are

New Batteries, in both RX and TX.
New Failsafe.
New Servo.

The only thing I haven't tried is a new transmitter, which I should be able to do soon as I have another one coming.

Can anyone suggest anything else I can check.
 
If it does it while it's off and you have a new servo and pack....you might be looking at crystals.....if that's not the case then it's radio time....do you know anyone you can borrow radio gear from and test yours w/
 
Plaidfish said:
If it does it while it's off and you have a new servo and pack....you might be looking at crystals.....if that's not the case then it's radio time....do you know anyone you can borrow radio gear from and test yours w/
Click to expand...

Ok, I will try the crystal's.

I have another MT on it's way to me now and I will try the radio gear from that.

Cheers
 
Tried the 2nd controller and it didn't seem to do it.

Then I tried the traxxas controller on my new truck and it did exactly the same with a different crystal. Looks like the Radio is knackered.

Guess I am in the market for a new transmitter :2cents:
 
try adjusting your trims alittle i had mine do something similar ,it would pull back at WOT then go right to idle just like you left go of the trigger ,but i trimmed it backalittle and it was fine
try that
 
Ok, first, what brand of fail safe? I had a Dynamite fail safe that just didn't like my Futaba 2pl or 3pm computer radio. Also, if the servo is stalled at the end of it's travel, that could cause a current spike that is making the fail safe think you have a low voltage condition. Are you running a receiver pack instead of just 4 AA's? If you are running 4 AA rechargeables, then your voltage at servo idle is only 4.8, and that's pretty low. Get a good receiver pack and charger. A 6 volt pack, if your servos and receiver will take it makes everything work faster.....
 
Yeah, I have got around it by slightly trimming the throttle down. It works fine, I would have just liked a solution.

It isn't down to the make of failsafe as I have tried 3 different brands.

From the looks of it I would say the end point of the throttle servo stops before the trigger reaches what it thinks the end point is and because the failsafe interprets this continued signal to accelerate as a error and kicks in.

I can life with it by trimming it out, I was just interested if this was a known glitch with the traxxas tq3 or if I had a faulty transmitter.
 

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