I dont know if this is the right place to be asking the question but here I will try anyway. I have the futaba 7cap radio and on my new plane that I have it has 2 elevators and I think I saw some were that if you have the 2 elevators on different channels and mix them you cant trim it. Is that true?

Thanks

This is true, dual servos for the same control surface is the achilles' heel of the 7CAP/7CAF radio. You have to use some kind of external servo balancer or something in order to make dual servos work.

RC Groups posted a review of the 7CAF/7CAP radio system, and summarized the issue as follows:

"The 7C's big weakness in airplane programming is that it does NOT support twin elevator or rudder servos in any manner. Programmable mixes that don't include link or trim make twin elevator or rudder servos impossible to do properly or safely, except with a y-harness or servo synchronizer. (If you use a mix for 2 elevator servos and use the elevator trim, only the servo in channel 2 is moved; the 2nd elevator would not be trimmed, resulting in roll every time you give elevator. For rudder it would be even worse, as the 2 servos would be fighting each other to move a single rudder)."

The 7CAP is a nice radio system, but considering the Airtronics RD8000 is available for around $250, this lack of support for twin elevator or rudder servos is a glaring omission. I like my 7CAF quite a bit, but eventually I'm going to have to replace it with something more sophisticated.

Due to it's weaknesses, I have never recommended the 7C as a viable transmitter to any of my students or friends. It is a shame they got rid of the 6Xea's. It was a better radio than the 7C.

Wow, Geistware, that is a pretty powerful condemnation of the Futaba 7C. I bought my 7CAP because I wanted a full-featured computer radio that could handle both airplanes and helicopters, wasn't ridiculously expensive, and would be easy to operate and program. Another factor in my decision was my owning of a Futaba 4YF radio and a Futaba buddy box. Choosing the 7C allowed me to use my 4YF and/or buddy box with my new radio as well.

The 7C has its limitations, and the lack of dual elevator servo support is certainly the most glaring one. It is a great radio system overall, however, and it's a terrific fit for folks like me who already owned Futaba transmitters or buddy boxes and wanted something more advanced that would still be compatible with their old equipment.

I use my 7C for sport planes, entry level pattern planes, and indoor and outdoor electrics. It's been a terrific radio, and as long as you know dual elevator servos will require an extra accessory, it's a perfectly viable choice.

I bought the radio new when I got my second plane and at the field I was seeing more people with futaba that jr so I decided to go with 7cap. I have like it so far, it has been nice and pretty easy to work with. I was wondering what I should use for dual elevators? Reversing Y harness or something else. I am getting pretty close to fly it so I am glad I ask.

Thanks for the help

rc-plane

P.s do any of yall have expirence with YS engines? Just got mine in to day and wondering what glow plug to put in it. If you dont have any expirence do you know were I should ask this question?

OS "F" type is the recommended glow plugs for most YS engines.

Ken

Thanks that is what I thought, this is my 1st four stroke so I dont know much. I have herd they are good for a lot of the engines but in the manual it said to use YS plugs but I guess any company would say use there stuff.

Thanks

this may not be the cheapest way to do the job but will certainly do it.

http://www2.towerhobbies.com/cgi-bin...p?&I=LXCTS1&P=

Yea just a tad bit on the expensive side!!!!!!! Cant spend that much on something like that.

But thanks

http://www.futabarc.com/radioaccys/futm4150.html
http://www2.towerhobbies.com/cgi-bin...&I=LXANF2&P=ML

A little bit cheaper. Gonna be hard to find much cheaper and be of any quality.

Couldn't find instruction sheet. Reversing might not be mandatory and you could always just use other side of output wheel if installation would allow for that.

I have had the 6Xa's, 8U's and 9C's.
I have used or programmed all the Futaba radios with the exception of the new 4 channel computer radio, 12 and 14 channel computer radios. I would recommend the 6X over the 7C any day. The 7C is easier to program. It looks like the 9C. It has a lot of short comings that is not compensated by the additional of one more channel.

What most modelers have asked for when you get beyond the basics and brand wars is reliability, programming ease and features. Not more channels. More channels may be easier, but what is needed is a radio that is easy to program and with more features. I am a Futaba guy. Not because I think it is better, I am a Futaba guy because I understand it's short comings and can usually program around them. I don't mind that. What I do mind is repeating the same mistakes. It is NOT the fault of the people here in the USA, or Futaba corporate. Sales and marketing will give people what they will buy. Many times that is esthetics in place of functionality.

This is waht I'd do. Go hitec digitals on the servo, get the servo programmer or borrow it, sync up the servo's and run a heavy duty y connector. To get the elevator servos to truely synchronize, you'll need to do this method anyhow. I dont know what style A/c it is, but for my IMAC airplane, servo programming is a must.

IF you have a 7CAP (or any other radio that wont provide a mix with trim for 2 channels) i would never use an inline or Y reverser, they are JUNK! they never remain on centre. The JR matchbox is the only way, you can link upto 4 seros together, control null zones and reverse any servo, they are brilliant.

By the way i have just discovered JR radio after using futaba for 25 years....Man that JR stuff is so easy to program and of far better quality....

Cheers

Wavy

I am often amazed at the 'futaba' loyalty and how persistent they are that they have the best. Well, obviously, in the 7CAP issue, they clearly have a sort of a lemon. There are several other radio manufacturers out there that produce systems that are either the same cost or less expensive and do exactly what you want them to do.

I, for one, have three different radio manufactured radios. All of them do what I wanted them to do when I bought them. There was no particular loyalty to a brand just "because that's all I have ever bought". I get what I need and go from there.

I have mainly found Airtronics to do just fine, but also have a new DX7 that does the job equally (if not better in some instances) and for the applications I have, they all do what I need them to do.

If you can show me a reason to solely stick with Futaba, or Airtronics, or Hitec, or JR, or whatever, please let me know. I don't think, with my abilities, I will ever see the difference. They will all do fixed wing, helicopters, SAM, sport, pattern, IMAC, whatever, just fine. It comes down to a preference and what you want to do with the radio, and buy accordingly.

DS.

Now watch the incoming... let me get my helmet and flack jacket before you reply. [X(]

Sticking to one brand USED to be a lot more meaningful than it is today, but nowadays a lot of the periferals are interchangable.

But there IS still some logic in sticking to one brand. Swapping chrystals for example. Or needing a "Y" cord for two Futaba Servos and having 3 JR "Y" cords available.

Sure, you can cut the little tabs off of the Futaba servos, but why have to?

Not to mention the time I DEcharged my JR tx the day before an event because I forgot to switch the damn leads on the charger! [:@]

Oh yeah, Minn. I know what that's all about. I have Airtronics and DX7. Of course, the DX7 has the reversed polarity connectors for the TX battery.

I have two Sirius chargers. One is standard and the other one, well, I intentionally modified it so that it will charge ONLY the DX7 TX battery and labled it as such with big bold black letters. What a way to live. Sirius comes with a set of adapters, but I just don't want to have to think about it when I am looking everywhere for those damned adapters.... you know.. "I know that I put them away, but where did I put them?"

Now why can't JR and Spektrum get with the program and put the + on the center lead like most of the rest of the industry is a puzzle to me and probably to many others.

I originally thought I was brand loyal until Spektrum. I now have a mix of servo's, receivers, and two, well, acutally four (three Airtronics and one DX7) transmitters.

DS.

Too late now with so many units already in the field. It would cause mass confusion amongst JR users.

Sorry to bring up such an old post but I wanted to bring a a less expensive alternative to all 7cap radio users. its called programming,
if you set up a user program and hook up the the second elevator channel to channel 7, you can use channel 7 as a slave to channel 2 which will be the master elevator channel. Set this program as null (meaning always on) set up your epa and sub trim channel 7 for parallel operation with channel 2 and it will work the same as any other mix on any other computer radio. I guess futaba just plain forgot to explain this in the manual (pretty stupid on there part) but the radio does have the ability for dual elevator servos.

I also have a 7cap, and I am looking at black horse bravo 303 pattern plane which uses dual elevator servos and I was very upset that I would need a synchronizer for the second servo so I while reading my instuctions I found out why futaba added 3 user defined mixes. I still think they should have added this as a setup procedure in the book.

Rc-plane as long as you set the program to 100% synch with channel 2 you should have no problem with trim I am in the process
of setting up this program on the bench with servos and I will post the setup instructions once I have it all ironed out.

Well guys I am a moron for more reasond than 1 first off the trim doesn't work for the slave servo, 2nd for the money paid for the 7c
and the fact I have to buy a synchronizer I could have easily got a 9c. Well we live and learn.

Thanks I got a servo reverser and it worked good today. The plane did good except dead sticking and then crashing. It's fixable so I will be all right. Thanks for all the help!

overbored the trim will not trim both channels only the master channel

I'm done with Futaba.

I use this SR-10 in my Edge 540 for dual elevator servos. I haven't had a problem with it holding it's trim.

Price is slightly offset by the fact that the cables reach 24 inches long, so you don't need to buy additional extension wires to get to the tail mounted elevator servos.

I use it with my Futaba 6EXA-S.

7C looks cool.

Too bad you have to spend $300 on a 9CAPS to get transmitter based P-Mix Linked Trim ... make that $400 (I don't see the transmitter only package at Tower any more). Heck, might as well spend $500 and go synthesized!

I also have the 6EAS its a fine radio for my needs I should have gotten the 7 CAP, I ended up using the MSA-10 it is a pricey little item but it does get the job done I used it on my U CAN DO 3D, I did work it into a tower order/discount, so I saved a few $$ on it works like a charm.

One point of the original post was trying to set up a dual elevator servo on a particular airplane. I have two aircraft that have the split elevator setup, but used one servo to control it. It just requires careful setup using two side-by-side pushrods. See the picture. This way, you can set up your elevator on the elevator channel and just forget about it.

Proper and careful setup of the length of the two rods, one on either side, then the adjustable clevis on both ends, well, you've got an easy and strong system. I use this on two large aircraft and both are fully aerobatic with no tendency to soften in strong loops. Smaller aircraft can use the 2-56 carbon rods and the larger ones can use the 4-40 carbon rods. Either way, you save weight by removing one servo and put the servo around the CG for control rather than two back where they can cause CG problems.

DS.