bafflerback

My Feedback: (6)

A customer came into the Hobbyshop where I'm working looking for a reverse servo to use on the elevator of a Foam EDF. Not stocking much in the line of reverse servos I asked why he didn't use a y harness with a reverser. He informed my that Spektrum advises not to use them. This surprised me as I'm currently flying 2 aircraft with them installed. The only thing I noticed using the reverser instead of mixing is one elevator is a little slower than the other. It's only noticeable if you slam the elevator stick. The airplane flies fine.

Anyone know the reason that Spektrum doesn't recommend the use of a reversing Y harness.

Zeeb

My Feedback: (41)

All I can tell you is that Spektrum considers reversing Y-harnesses a definite NO-NO.......

BarracudaHockey

My Feedback: (11)

This is correct

AndyKunz

Because doing so can cause delays in response time. This is especially important if you're flying an aerobatic model. One servo (the directly-connected one) will always lead the other. A MatchBox is a better choice here than a single-channel reverser.

They also may not have the same "center" position as the receiver. Early Spektrum receivers used the same 1520 microsecond center that JR receivers used in both the FM and DSM products. Newer Spektrum designs use 1500 microseconds.

Was it not possible for the guy to use the other side of the servo output arm for his installation?

Andy

c/f

My Feedback: (1)

Ive used them in flaps on jets where servo tracking speeds is not an issue as I slow them down anyways and activate on base final turn. What I did notice and these where with the EXPERT brand, (a JR private label,) was that outside temperature differences required me to adjust the centering pot provided. I concur having used them they have there shortcomings.

modtron

Many years ago Futaba made an item called an SR-10, which had a single line input and 2 outputs.
One of these was normal direction, but the second was reversed with an adjustable neutral via a small pot on the top of the case.
They cured the delay by having the input signal buffered before having anything done with it,
Then the 2 outputs were also sync'd together and no timing issues occurred.
There are still some around if you can find them.

modtron
Oxford UK

init4fun

In the good ol days those of us who were into electronics had a simple solution for reversing a servo . It was a 5 minute job to open the servo , swap the two outer wires going to the potentiometer , and also swap the two wires going to the motor . I haven't opened up a modern servo lately and wouldn't be surprised if this old fashioned solution is no longer viable , if the motor is directly soldered to the circuit board or if an optical encoder VS a potentiometer is used for instance , I'd bet the old trick wouldn't work ...