Hooked-On-RC

My Feedback: (16)

35% Aeroworks Extra 260 QB

JR8611 Servos, one per elevator half
Air Wild 1.5" Servo Arms
Futaba 9CAP radio
Futabe 149 receiver

Trying to coordinate elevator halves...how do I synchronize those two servos so they center the same and move the same distance?

No remarks about hitec servos please...

cmoulder

(OOPS!! Self deleted!)[]

Bax

My Feedback: (11)

To begin, you want to use the "Ailevator" function in the transmitter, and then turn off the aileron part. That gets the two channels moving together.

Now, turn on the transmitter and receiver. Make sure the stick and trim are centered. Adjust the position of the servo wheel or arm so that it is in the EXACT center position. If the arm or wheel seems to be off by one tooth on the post, turn it 180 degrees. You should be able to get it dead on. Now adjust the location of the pushrod on the servo arm and control horn at the control surface to get the centering exactly where you want it, and with the throw you want. Do this on the primary channel first, it should be channel #2. Now do the same thing on the second channel. Get it as close as possible mechanically, and then use the % values in the ailevator mixer to fine-tune the throw to match the master channel.

hlhamner

Bill,

What you say doesn't appear to work. When you use the Ailevator function on the 7C to get the same total degrees of throw the throws at 50% of stick movement are different. Also, when you change from dual rates at 100% to dual rates at 40%, as an example, you have to start over with the synchronization. Yes, I am an experienced modeler and the mechanical setups are exactly the same on both elevator halves.

It took me almost 45 minutes to get 2 Futaba S9451 servos in synch at the full throw points and then I can't get them to synch up at the transmitter 1/2 position without changing the full throw adjustment. I've given up trying to figure out the dual rate issues. I've sent an email to Futaba tech support but no response yet.

I have a Futaba MSA-10 Servo Synchronizer and the same problem exists using it also.

What is going on that makes this is so difficult?

Bax

My Feedback: (11)

When you use a mixer on a 7C, you will only be able to set the endpoints of the mixed channel. If the servo is faster or slower, then you'll get variances between the center and the endpoint. The only way to eliminate this is to use a higher-level transmitter than will allow you to adjust the in/out speed of the mix and possibly add mix points to the the mix curve. The 12FG, 12Z, and 14MZ all will allow you to do this, so you can get the servos perfectly mixed. Lower-level transmitters just don't have that, and you'll have to live with the differences between the servos.

If you need the degree of precision you're asking about, then you'll need to get a transmitter that can deliver that precision. The 7C is not of that caliber.

hlhamner

Bill,

Thanks for the quick reply. I really love my 7C and Futaba radios in general but this lack of functionality baffles me. I really thought the ailevator function would perform as advertised. For what's worth, the Spektrum 7 has the same problem but not the more expensive JR 9303.

A friend of mine says he uses Hitec digital servos and has a Hitec servo programmer that can do all the adjusting so that the servos are exact. Then the 7C ailevator will work as expected. You probably don't know if this will work or not but I'll check it out with a couple of less expensive Hitec servos I have to see if he knows what he's talking about. I can't afford to spend $1,200+ on a high end Futaba system to take care of synching up dual elevator servos which are pretty common on lower end airplanes like the Showtime 90, and U CAN DO 60. You'd think that $100 S9451 Futaba servos would be matched for speed, etc. before leaving the factory.

I was thinking of upgrading to the new 10 channel Futaba 2.4. Will it work to handle the Ailevator functions like the 12Z, etc?

Hank