Wide open throttle (servo horn adjustment)

[grizzledcamudgen]

Well, I have my servo in my truck now and I'm trying to figure out what the deal is with the throttle kicking to wide open once powered on!


O.K. I turn the TX off and the brakes are applied, perfect!


When I turn the power back on it goes to full throttle!


I left the TX on and lifted the horn off the servo and leveled it


across but same thing happens when I turn the TX off and then on again!


I have done this lifting and leveling about 15+ times and still the


same thing happens! Full throttle once powered on! O.K. now, what


am I doing wrong?


Hmmm...?

 

[Deluge]

What servo are you using? What radio system? Are your trims set properly?

 

[grizzledcamudgen]

What servo are you using? What radio system? Are your trims set properly?

I'm using a 4PK with a HS-5645MG servo.


The trim settings is a good idea, I will check on those!

 

[krashkrieg]

Turn on transmitter and leave receiver off....go through and reset Trim and EPA back to Zero....shut it off then back on...turn on receiver (car) without servo horn on and let it zero out...now put the horn on....you should be good to go...If not you might have a bum servo.

 

[grizzledcamudgen]

Turn on transmitter and leave receiver off....go through and reset Trim and EPA back to Zero....shut it off then back on...turn on receiver (car) without servo horn on and let it zero out...now put the horn on....you should be good to go...If not you might have a bum servo.

That sounds like a winner, I'll try that here in a minute. What is EPA?

 

[looker2756]

That sounds like a winner, I'll try that here in a minute. What is EPA?

EPA is (End Point Adjustment). This decides how far the throw of the servo is. It is used if you have a servo that is going to move farther than needed. You adjust the EPA so that the servo is not stressed by having to much travel.

 

[grizzledcamudgen]

EPA is (End Point Adjustment). This decides how far the throw of the servo is. It is used if you have a servo that is going to move farther than needed. You adjust the EPA so that the servo is not stressed by having to much travel.

Whoa, that sounds a little in-depth! I never heard of that, I'll have to check up on it in the novel sized manual for this TX.


Hmmm...sounds a little complicated!

 

[v555]

Well, I have my servo in my truck now and I'm trying to figure out what the deal is with the throttle kicking to wide open once powered on!
O.K. I turn the TX off and the brakes are applied, perfect!


When I turn the power back on it goes to full throttle!


I left the TX on and lifted the horn off the servo and leveled it


across but same thing happens when I turn the TX off and then on again!


I have done this lifting and leveling about 15+ times and still the


same thing happens! Full throttle once powered on! O.K. now, what


am I doing wrong?


Hmmm...?

if you lifted the servo horn to the right point with powered transmitter/receiver then problem is in servo and there is nothing more to adjust.if you adjusted it without power then do as krashkrieg said or just reset the model. same servo that you repaired?

 

[grizzledcamudgen]

I am at a loss, I don't understand why this doesn't zero out. I reset the trims on my TX to "0" took the horn off then turned the truck on, put the horn back on level then turned the truck off then back on and it still went to full throttle.


I looked at the EPA thing on my TX, I have no clue about this, it shows everything regarding EPA at 100.


I wish I had someone close by that has a 4PK to walk me through this stuff!


The servo I have in my truck is the brand new one that I just got in the mail, HS-5645MG, I still have the one with the gear change. I haven't done that yet.


Hmmm...what to do

 

[hamster huey]

Did you zero it out like V55 said with the power on and install the arm at zero with the transmitter and car power on? You zeroed trim, subtrim, and epa?


Is the car and transmitter on at the same time when it goes wide open or just the car. If just the car is on but not the transmitter your failsafe might be set to wide open instead of full brake.


Make sure its plugged into ch2 and not 2 postion channel 3. Also make sure your 4pk is not set to 2 postions for channel 2.


When the problem happens can you still control the servos? So only at neutral its going to wide open?

 

[hamster huey]

I just remembered something about those 3pk and 4pk. They have a feature for during a programmed amount of time the throttle goes to a programmed point when first turned on. You have to turn that off. I think its called "idle up". Its very useful for nitro but thats about it. That could be your prob. maybe?

 

[looker2756]

I am at a loss, I don't understand why this doesn't zero out. I reset the trims on my TX to "0" took the horn off then turned the truck on, put the horn back on level then turned the truck off then back on and it still went to full throttle.
I looked at the EPA thing on my TX, I have no clue about this, it shows everything regarding EPA at 100.


I wish I had someone close by that has a 4PK to walk me through this stuff!


The servo I have in my truck is the brand new one that I just got in the mail, HS-5645MG, I still have the one with the gear change. I haven't done that yet.


Hmmm...what to do

This seems rather confusing, & you have the Most Advanced controller on the market, which also makes set-up much harder IMO. The truck & radio must be on & at idle settings. Then install the servo horn in the idle setting. At this point with everything still on, turn the transmitter off to check the failsafe setting. Turn the transmitter back on & make sure it goes to idle, Not brake. If all functions good. The radio should be set-up correctly. Turn all off Then back on & recheck all those functions again. As rule of thumb goes, Always turn the transmitter on first, Then the truck. I don't use a Futaba, because of this complicated set-up, but it's a great radio used by many. I know a 3pm the failsafe must be set every time, I don't know if a 4pk is the same or not. I know some don't like them, but this is Exactly why I use a Spektrum DX3R.

 

[grizzledcamudgen]

Thanks for the advice HH! I just checked it and it is off.

 

[hamster huey]

I sold my 3pk so Im going by memory. Are your servos reversed on the transmitter? is throttle assigned to the trigger?


What does it do after its turned on and goes to full throttle? will it let you move the trottle w/ the trigger? Is it only wide open at neautral? Is your receiver battery fully charged?

 

[grizzledcamudgen]

This seems rather confusing, & you have the Most Advanced controller on the market, which also makes set-up much harder IMO. The truck & radio must be on & at idle settings. Then install the servo horn in the idle setting. At this point with everything still on, turn the transmitter off to check the failsafe setting. Turn the transmitter back on & make sure it goes to idle, Not brake. If all functions good. The radio should be set-up correctly. Turn all off Then back on & recheck all those functions again. As rule of thumb goes, Always turn the transmitter on first, Then the truck. I don't use a Futaba, because of this complicated set-up, but it's a great radio used by many. I know a 3pm the failsafe must be set every time, I don't know if a 4pk is the same or not. I know some don't like them, but this is Exactly why I use a Spektrum DX3R.

I tried your procedure and its a no go. turned it on and "BAM" full throttle!

 

[grizzledcamudgen]

I sold my 3pk so Im going by memory. Are your servos reversed on the transmitter? is throttle assigned to the trigger?
What does it do after its turned on and goes to full throttle? will it let you move the trottle w/ the trigger? Is it only wide open at neautral? Is your receiver battery fully charged?

The servo is not reversed & yes.


I can move the throttle with the trigger after turning it on, full throttle.


The battery has a full charge.

 

[hamster huey]

When its at neutral and stuck as you said what happens to the servo when you squeeze the trigger to full throttle?


When youre at neutral and its stuck at full throttle what happens when you push the trigger to full brake?


Is it possible the teeth on the servo horn are boogered or don't match the number of teeth on the servo?

 

[grizzledcamudgen]

When its at neutral and stuck as you said what happens to the servo when you squeeze the trigger to full throttle?
When youre at neutral and its stuck at full throttle what happens when you push the trigger to full brake?


Is it possible the teeth on the servo horn are boogered or don't match the number of teeth on the servo?

ok, this is a little strange!


when I turn it on it goes to full throttle, if I give the throttle a tap, it (horn) goes to neutral! Then when I apply the brakes and let go it returns to full throttle, I have to tap the throttle to get it to go back to neutral!


Hmmm....?

 

[hamster huey]

Is your "start" function for throttle turned off? Its on page 65 of the manual.


Is your mixing/boat modes turned off?


Have you tried setting up with the basic level one settings? It eleminates alot of the things the transmitter can do to throttle.

 

[hamster huey]

I think if I was you and didnt have a bunch of saved models in your transmitter I'd reset the thing and try to set it up in level one. And Id start w/ freshly charged batteries, check channels plugged into, etc, etc, and program the failsafe last. Im out of ideas........