View Full Version : You have 2 servo's running your split elevator. REVERSER?
02-27-2004, 11:23 PM
What reverser do you use and why? I am doing my first split elevator dual servo setup and need a reverser. I have a Futaba radio and plan to purchase Hitec servos for my elevator. The Futaba reverser is expensive @ $50. I have my eye on http://www.emsjomar.com/ and their reverser for $20 US.
PS. I will be running 6 volt Rx battery.
02-27-2004, 11:57 PM
I use a EMS servo reverser on my u can do, works great.
Make sure you get the one with the Y connection, one servo
travels normal the other reverses for dual servo elevator set up.
I have a 4.8 v 1100mah in it with no problems.
02-28-2004, 06:58 AM
If you get some basic Hitec digitals, ask at your LHS if they have a programmer and reverse one of the servos that way. There is also a mixing capability depending on your radio, isn't there?
Just some thoughts
ps I doing my first this year as well so these are the options I'm looking at myself.
02-28-2004, 08:17 AM
My radio doesn't offer this feature.
I will look into the digital programmable servo option, but expect it will be to costly for me.
I use the reversing Y cords, they work fine.
I paid $20 or less for mine, check hobby-hobby.
02-28-2004, 10:02 AM
The price on the new Hitec Standard Digital servos is very reasonable. I have two brand new in the box Hitec Standard Digitals that you can have for $45 each, no tax, no shipping. Great Hobbies price $46.65 each plus tax and shipping.
Specs: HS-5475HB Standard Digital. Heavy Duty HB gears 4 X stronger than regular plastic gears! 61/76.4 in oz torque at 4.8v/6.0v. Wt 40g Speed .23/.18 at 4.8v/6.0v
As far as the digital programmer goes, I have one that just sits here most of the time that I would be pleased to loan you. Freelton is only a few minutes from Stoney Creek. Doing your setup this way means a lot less fuss on the setup, less connections meaning less things to go wrong. Also eliminates the weight of the "Magic Y" although its not that substantial! You said you had to purchase Hitec servos anyway, so this is worth considering!
Just thought I would offer!
02-28-2004, 03:11 PM
Wow, what a great offer, thank you.
I would jump on it except the servos I am putting in the tail need to be higher torque. I was planning on putting the Hitec 645MG's in (133 oz/6 volts).
02-28-2004, 04:17 PM
Thats a lot of torque what size airplane you using and engine??
02-28-2004, 04:39 PM
Kimbo I am putting together a 1/3 scale Pitts from Great Planes and I will be using the same servos Gary has offered to sell you. This plane will have a Moki 2.10 in it. Unless you use the digitals which will allow you to program centering, speed, end point etc right in the servo you will not have any of these fine adjustments with a standard Y reversing harness.
What I am trying to explain is that the standard Y reversing harness only reverses one servo and will not let you independently set up centering or end point on each servo. In other words other than mechanical adjustments any trim changes or adjustments at the transmitter will affect both servos
There is a solution and itís called the JR matchbox. I believe Futaba has one similar but I am familiar with the JR unit. It plugs into one channel and you get to control 4 servos from that unit all independently adjustable. Each servo can be reversed, centering and endpoint adjusted. In other words you could match up your two reversed servos identically. I just used one to match up all three throttles on my Tri-Motor and it worked like a charm. I have watched a guy with a standard flash 5 radio set up and fly a large aerobat using two of these units. One controlled the 4 aileron servos 2 per aileron all matched for centering and end point and one side reversed. The other he used as in your application with the split elevator. It worked perfect for him as he did not want to spend big bucks for a high end radio.
02-28-2004, 05:21 PM
No problem Adam. It would be helpful to know what plane your talking about.
I'm going to be using these same Digitals in my AV8R Turbine Jet!
02-28-2004, 10:06 PM
I am building a Byron Originals Pitts Special (1/3 scale). It is identical to the Great Planes ARF. The difference is it isn't an ARF and is by a company that has gone belly-up (no ordering replacement parts).
02-28-2004, 11:06 PM
Thanks for the info on your plane Adam.
I do still believe that the standard digitals would be enough servo on the split elevators for this plane. You would be using a 76.4 in oz servo on each half of the elevator. The only exception I may have would be maybe with the rudder servo needing to be a higher torque. Just keep in mind that the Byron kit has been around for a very long while and was origionally designed to be used with servos that were available at the time, servos that we now call standard servos of around 43 in oz of torque.
But your the one who has to be comfortable with what equipment you will use on this plane
Please know that this was not meant to be any kind of a critisizm. My offer was only meant to help you out!
All the best with your project!
02-29-2004, 06:55 AM
All feedback and recommendations are welcome. That is why I am here!
I am putting a 1/4 scale 160 oz torque on the rudder. (I bought it a few years back).
I am buying new servos (probably @ Toledo) for the ailerons and elevator. For those I am looking at standard size, very high torque. I am looking at very high versus high because of my comfort level. I have a Quadro 50 for the kit and when I come straight down from high altitude @ full throttle and I then pull up (level out) at low altitude for as fast as possible low flyby of the field, I want no worries about the strength of the elevator. A few more bucks give me that comfort level. I just bought new high strength control horns (Du-Bro teflon). The ones that came with the kit were cheap, little 2-56 nylons. The kit also came with 2-56 rods that I scrapped for 4-40.
Like Tim the Tool Man ... more power! 8)
I flew my 1/3 Pitts with 2 standard 148 servos on the elevators, with a servo reverser Y cord, and it worked fine.
I switched to JR4721, and the control was a bit more precise, but nothing major. I let an Unlimited IMAC pilot fly it, and he could not believe they were standard servos until after he landed and looked at them himself.
Standard high-torque servos would be fine on this plane, digitals a bit better. If you decide on non-digitals, just use a reversing Y cord. The digitals Gary has would be an excellent choice, and he could program them for you. You certainly don't need more than those on the elevator.
For your ailerons, if you are using 4 servos, standard torque is fine.
If 2 servos, higher torque is necessary, but extra high torque is not. Choose servos for your ailerons that are more precise and higher speed over extra-high torque.
No offence to any previous post intended, just my opinion based on first-hand experience. :D
02-29-2004, 11:09 AM
Thanks for the input.
I am going with a digital extra high torque on the wings for the precision and my own comfort.
I will give more thought to the offer above in regards to the elevator servos.
I have a Quadro 50 for the kit and when I come straight down from high altitude @ full throttle and I then pull up (level out) at low altitude for as fast as possible low flyby of the field, I want no worries about the strength of the elevator.
Adam, I don't know how much experience you have with giant scale, but if you go straight down vertical at full, or even high throttle, your beautiful Pitts is going to disolve, and the largest servos in the world will not save you. :shock:
The good news: a company called "Iron Bay Models" has taken over production of most of the Byron kits, and you may be able to get a replacement! :wink:
02-29-2004, 06:03 PM
I am inexperienced with Giant Scale.
Good info ... i'll take it a little easier than with my Extra.
03-01-2004, 10:37 AM
i have a byron christen eagle (byron is now ironbay model company)
i run 2 elevator servos with no reverserbut changed the wires in the 605 hitec servo and works great and mor importantly at the same speed and direction so u might wanna look into that option Mine has a MDS 218 in the front talk about power
A while ago I bought a y harness from Hobby Hobby in Streetsville (great store :wink: ) that reversed the servos and has a little potentiometer so you can get both servos aligned for about 20 bucks. Don't know if they still sell them, but it worked flawlessly for two years in one of my pattern ships. If you are going to spend the bucks on a gas powered plane you might want to spend your money on a decent computer radio whereby this talk of y harnessess is moot. Now I simply mix channel 2 and 7 and reverse one, dial them in and watch the magic!! Ain't technology grand :roll:
A while ago I bought a y harness from Hobby Hobby in Streetsville (great store ) that reversed the servos and has a little potentiometer so you can get both servos aligned for about 20 bucks.
That's the one I had mentioned earlier.
It's still working in one of my planes, even though I have a computer radio now and could get by without it.
03-01-2004, 06:06 PM
The product your talking about is made by: MPI and its called a "Miracle Y servo reverser"
This is what I used in my Sig Cap to reverse one of the elevator servos. It does have a POT for fine tuning the throw of the reversed servo. The other servo is centred and EPA made through the radio.
They are around $25 at Hobby stores where MPI products are sold.
If I may add, I would not ever recommend tearing a servo apart and rewireing it. It definitely voids the warrenty and is NOT worth the chance you'd be taking of servo failure. Spend the $20 and buy the Miracle Y if Digital Servos are not a consideration.
03-01-2004, 06:55 PM
I have the Futaba 6XA computer radio. It doesn't have the elevator feature you are refering to (I will double check ASAP however).
I am probably going to go the route with Gary and do 2 digitals and program one to be reversed. They are a bit less torque than my original interest, but if the extra torque is useless for my application, it is better to have a digital servo and program one and save the $.
03-01-2004, 08:48 PM
Adam what I was refering to is End Point Adjustment (EPA) Most computer radios do have this feature althought I am not familiar with your radio setup. You can mechanically set the centre and use trim for the one elevator half and use the pot on the Miracle Y to adjust the second half to be even with the first.
Anyway I think the digital servos is definitely the way to go for ease of setup and I still do believe the torque is more than adaquate for your plane! Plus you have the advantage in holding power with the digitals compared to the standard (analoge) servos.
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