Reversing A Servo
 

I have two planes set up on an analog radio and everything works fine except I have to reverse the rudder servo when changing planes to fly. I can reverse the servo direction by removing the battery cover and moving the reversing switch but was wondering if switching two wires on the servo would do the same thing?

Its funny that I have two old computor radios with three model memory on one and 10 model memory on the other and only have one plane set up on each of them. My analog is a Hi-Tec Laser 6 channel that I really like. I have my new LT-25 and a Big Stik 40 on this one radio. Anyway just a question for you radio wizards.

You have to switch the wires on the motor and the outside wires on the potentiometer. Just reversing the wires at the plug will fry the servo.

Speed that what it seemed like I remembered. But relying on my memory is a shaky thing at best. Oh well, I have an extra receiver for my JR computor radio and may just switch that out instead. But thanks for the speedy answer to my dumb question. TT

Can you afford to spend $3.00 ?

http://www.hobbyking.com/hobbyking/s...arehouse_.html

Radforc I didn't know such an animal existed. Heck yeah thats the way to go. Thats simple and I like simple. I will order a couple of those and I need a new reciever battry pack also. Thanks for the heads up.

Note that different brands of servos operate in different directions with the same transmitter command. Just change out the one servo you want to reverse with a different brand. You will have to experiment to see which brands operate in which direction.

I am using Hi-Tec 485 servos. Do you know what runs in a different direction and uses the same plugs?

Yes all Hitec and Futaba servos by factory default run in the opposite directions. This can be successfully done using two similar sized and performance servos of different brands and I have done this in certain flap installations not flaperons and this should never be done in the case of two ailerons servos or two elevator half servos. Using two different brands within the airplane that are just single servo functions is perfectly fine. Depending on the receivers used you may have to shave the plugs tab from the futaba servos.

There are other ways to acheve servo reversal beyond internal electronic reversal (which is not all that practical for most of us) and it involves linkage set up and or servo positioning.

So exactly what servo (function) is the one you need reversed?

John

Hello John. In the first post I said that it was the rudder servo I needed to reverse. So if a Futaba runs backwards from a Hi-Tec I may just go that route. You can't have too many servos. And I have been shaving Futaba plugs for many years. Changing the linkage isn't doable.

There you go Ratshooter just changing to a futaba servo is the obvious solution. I did do a reread of your first post and question and realized I had missed that part. I have Done the use of two different brands to acheve reverse output many, many times in the past.

I do remember in the past at attempts in flying two airplanes on one non micro processor controlled radios with model memories. It definitely is a challenge. Sometimes it can be marginally successful but usually only it the airplane types are similar. If there is a big difference in the airplanes type or performance then its not always a good idea.

I actually have just one airplane now that I do routinely fly with two different transmitters. This is rather rare situation indeed. The airplane is a vintage (1965) AMA aerobatic champion in what was then called class two, Aristo Cat. The primary radio system I intended for this airplane is my Orbit six channel system that I purchased in 1970 that I converted to 2.4. However I also wanted to fly at times to fly it with a modern very capable radio a Hitec A9. and the reason is it would offer many different choices and thing that I could do with the airplane. They old radio does not even have the most basic feature like servo reversing and of course this requires very careful placement of servos and linkage setup. Why do I do stuff like this? In a word Nostalgia and that can be a good thing. If you are a young fellow its likely you will understand someday. Heck if not anything else it sure makes us appreciate what we have now.

Just for you benefit file away the thoughts about servo placement and linkage perhaps for use later. Controlling the servos output direction just by placement and linkage is not all that hard to do even when its an arf and you may move the servo a bit. It does require careful thought and planning though but definitely food for thought. Hey its all about Learning:cool:


John

Hello John. I am not a "young fellow" at 57. I have been flying RC since 1979 with a couple of decades off to do other things. Thats two seperate 10 year layoffs. This is my third time around.

And I started with a Kraft KP4A and know all about not being able to reverse servos or have my favorite feature of all, being able to adjust the servo travel on the throttle. The throttle was the hardest thing of all to set up on the old AM radios I had. The trim worked even with the throttle wide open. So you had to get the linkage adjusted so wide open stick with full up trim didn't stall the servo. Of course then the idle was way to fast with the stick pulled down. So compromises were made. I use to go over to Ted Whites house to get my EK radios tuned and repaired. What a neat guy he was. And a heck of a pilot.

But I took your advise and went to the HS just a couple of hours ago and picked up a Futaba servo. Before this weekend I will have it swapped out on the Big stik. I am also going to give this plane a sex change from a nose dragger to a tail dragger. Then I think I may be up to another build before long.

Thanks everone for your help. And I looked at the link to HK. I may order a couple of the airborn battery packs from them. They were CHEAP compared to the HS. and I will also order at least one of the servo reversing wires. How good are their servos?

Excellent well you know what they say 'third time arounds a charm' . Only thing is converting a stick from a tri-gear to a tail dragger is not really a "Sex Change" its more just an 'Attitude Adjustment":cool:

I have never used a cheap single servo inline reverser so cannot comment but have used a reversing "Y" cord on a two servo split elevator installation. And while I cannot claim it failed it did cause some flutter that I was not happy with so my solution was to do some surgery to move the servo about an inch or so the two servos for split elevators could work properly with an ordinary "Y" cord.

John

John moving the servos would be way more trouble than just swapping a servo out. and I have done the reversing before by making a dog led in the control rod. But the big stick still has the nose gear and the LT-40 has a second pushrod for the tail wheel instead of the tiller bar tail wheel set up form the plans. A new servo that goes the direction I need it to go is a no brainer.

And a 3 dollar gamble for a servo reverser is not a problem. Especially since I plan on buying a couple of other things. And if if doesn't work, oh well, what the hey.

Attitude adjustment. That was funny. I like flying from grass much better than cement so a tail dragger is a better choice for me. When I had my first Little Stik and was trying to learn to land I broke a wood prop on just about every landing attempt. And if I remember Johnny Cashburn only sold wood props. (Smart Fellow) so I wood buy a dozen at a time. Finally someone suggested that I make my plane a tail wheel model and the prop breaking magically stopped. The light went on and I have owned very few tricycle geared planes since then.