Stupid New Servo...

[Russell Bear]

Here's what I have: 45 Roadrunner that had the two channel setup that I am now adding a third channel for fuel mix. I have a Futaba rudder servo, Hitec HS-81MG (Futaba connection) throttle and a new HS-81MG (JR connection) servo for the third channel. All this into a 3 channel Hitec Rx. Everything works fine with just two of the three servos plugged in, but when I add the third servo they all start freaking out. I tried a different Hitec and Futaba RX with the same problem, they both work in the other boats. If one servo is connected to either Rx they work fine, but when I add the third it goes crazy. I tried different batteries, moving servo leads to other Rx ports, other Rx's, switches, etc and they work fine until the third is plugged in.

What the heck is going on?

 

[Russell Bear]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

 

[Ray Sametz]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

 

[Russell Bear]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

 

[Walt Barney]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

Russel,

The problem may be in the servo with htec servo with the Jr end try to use a different servo in place of the Jr connection servo.

Walt Barney

 

[Propwash]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

I had the same problem at the beginning of the season and found that the servo had cold solder joints where the 3 pins go into the board from the pot. put another servo in place and problem went away. Try another servo , unmounted in the 3rd spot. if it goes away you know it's the servo, if not it may be the pins in the receiver.

 

[Russell Bear]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

Russel,

The problem may be in the servo with htec servo with the Jr end try to use a different servo in place of the Jr connection servo.

Walt Barney

Just tried that. Used two different servos. As soon as you put the third servo, regardless of what channel it is, it goes crazy.

 

[Russell Bear]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

I had the same problem at the beginning of the season and found that the servo had cold solder joints where the 3 pins go into the board from the pot. put another servo in place and problem went away. Try another servo , unmounted in the 3rd spot. if it goes away you know it's the servo, if not it may be the pins in the receiver.

Tried different servos. Tried two different Rx's that I know work in other boats. Like before, as soon as you add the third servo it goes crazy.

 

[Walt Barney]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

I had the same problem at the beginning of the season and found that the servo had cold solder joints where the 3 pins go into the board from the pot. put another servo in place and problem went away. Try another servo , unmounted in the 3rd spot. if it goes away you know it's the servo, if not it may be the pins in the receiver.

Tried different servos. Tried two different Rx's that I know work in other boats. Like before, as soon as you add the third servo it goes crazy.

Russell,

Try a different radio system transmitter and all.

Walt

 

[Propwash]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

I had the same problem at the beginning of the season and found that the servo had cold solder joints where the 3 pins go into the board from the pot. put another servo in place and problem went away. Try another servo , unmounted in the 3rd spot. if it goes away you know it's the servo, if not it may be the pins in the receiver.

Tried different servos. Tried two different Rx's that I know work in other boats. Like before, as soon as you add the third servo it goes crazy.

Hello Russell , How old is your receiver battery ? Have also seen when there is a larger load and one of the spot welds is very week or a bit of hidden corrosion on the back side of the tab. The only way I found that one was by cutting the shrink wrap off and taking a close look at all the connections on the battery pack, probing with a small pick. Just another thought. Geoff.

 

[nitrotwin]

hey russ its gremlins

 

[Russell Bear]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

I had the same problem at the beginning of the season and found that the servo had cold solder joints where the 3 pins go into the board from the pot. put another servo in place and problem went away. Try another servo , unmounted in the 3rd spot. if it goes away you know it's the servo, if not it may be the pins in the receiver.

Tried different servos. Tried two different Rx's that I know work in other boats. Like before, as soon as you add the third servo it goes crazy.

Russell,

Try a different radio system transmitter and all.

Walt

It works fine in the other boat though. I moved Rx's, batteries, switches and servos around and it works fine in the 60 boat, but the 40 boat it no like!

 

[Russell Bear]

I also deleted the memory on this one in my radio and copied the other boat that works fine into it's position. Still no workie...

Is the throttle or steering servo mixing into the 3rd channel??????

No sir, no mixing. They are stand alone.

I had the same problem at the beginning of the season and found that the servo had cold solder joints where the 3 pins go into the board from the pot. put another servo in place and problem went away. Try another servo , unmounted in the 3rd spot. if it goes away you know it's the servo, if not it may be the pins in the receiver.

Tried different servos. Tried two different Rx's that I know work in other boats. Like before, as soon as you add the third servo it goes crazy.

Hello Russell , How old is your receiver battery ? Have also seen when there is a larger load and one of the spot welds is very week or a bit of hidden corrosion on the back side of the tab. The only way I found that one was by cutting the shrink wrap off and taking a close look at all the connections on the battery pack, probing with a small pick. Just another thought. Geoff.

Tried a couple different battery packs and fresh alkalines in one pack. Still, same problem. Works fine in one boat, but not the other.

 

[Russell Bear]

hey russ its gremlins

I think your right JW.

 

[Bob Morton]

Here's what I have: 45 Roadrunner that had the two channel setup that I am now adding a third channel for fuel mix. I have a Futaba rudder servo, Hitec HS-81MG (Futaba connection) throttle and a new HS-81MG (JR connection) servo for the third channel. All this into a 3 channel Hitec Rx. Everything works fine with just two of the three servos plugged in, but when I add the third servo they all start freaking out. I tried a different Hitec and Futaba RX with the same problem, they both work in the other boats. If one servo is connected to either Rx they work fine, but when I add the third it goes crazy. I tried different batteries, moving servo leads to other Rx ports, other Rx's, switches, etc and they work fine until the third is plugged in.
Russell , Hetic servos have reverse polarity compared to a Futaba servo

What the heck is going on?

 

[Russell Bear]

Think I might have fingered it out. The old throttle servo (HS-81MG) may be bad. I can hook up any three combinations on three different Rx's, but when I put the old throttle servo in it glitches. Weird because it works fine alone, but hooked up with others it doesn't. Sure it has some sort of interference or drain going to it.

I'll pick up a new one tomorrow to see if it works.

Thanks everyone for the input....

 

[bzubee]

I've had problems with the 81 servos and have since switched to the 85 servos they seem to work better.

Think I might have fingered it out. The old throttle servo (HS-81MG) may be bad. I can hook up any three combinations on three different Rx's, but when I put the old throttle servo in it glitches. Weird because it works fine alone, but hooked up with others it doesn't. Sure it has some sort of interference or drain going to it.
I'll pick up a new one tomorrow to see if it works.

Thanks everyone for the input....

 

[Russell Bear]

I've had problems with the 81 servos and have since switched to the 85 servos they seem to work better.

Think I might have fingered it out. The old throttle servo (HS-81MG) may be bad. I can hook up any three combinations on three different Rx's, but when I put the old throttle servo in it glitches. Weird because it works fine alone, but hooked up with others it doesn't. Sure it has some sort of interference or drain going to it.
I'll pick up a new one tomorrow to see if it works.

Thanks everyone for the input....

I'll pick up the 85 then. Thanks.......

 

[Anders_Martinelle]

Russell , Hetic servos have reverse polarity compared to a Futaba servo

Since when did that hapen????????

Used Hitec servos together with Futaba along time w/o any problem.

Anders

 

[Rick Cesati]

Russell , Hetic servos have reverse polarity compared to a Futaba servo

Since when did that hapen????????

Used Hitec servos together with Futaba along time w/o any problem.

Anders

Russ...I have seen this. It IS specific to the latest 81s. The amplifiers go bad. Hitec has replaced two for me and will be getting another two from me next week. How old is your 81?

R-