Marcos Nieto

Hi guys..............I plan to buy a 75ccYak, my first large scale multi digital servo plane. I need some help on how to set up the servo array.
With such a high number of digital servos, 8 digital and 3 analog, the curret draw from the bat pack can be high and I'm not sure if this can be handled by a standard single receiver array(not sure on how a dual receiver array works).
I don't know if there is any recommendation on some special equipment like the power box, dual receiver, redundant bat packs, type of batteries, switches and so on.........I plan to use a Futaba MSA-10 servo synchronizer for the 4 ail servos.

Thanks

Marcos

Mark Dennis

My Feedback: (4)

Well for starters I don't know how you got to 11 servos. At most you should need 9 and that is with a choke servo. 9 servos will do fine on a single RX and battery.

Marcos Nieto

well I have 4 ail, 2 elev, 2 rudd, and throttle, choke and kill switch.........the last 3 analog servos

Marcos

Young-RCPilot

I am pretty sure the choke can be used as a kill switch and you could run a single servo on the rudder like a Hitec 5955. I would go with a single reciever but with 2 battery packs for rx and one for ignition.

bodywerks

My Feedback: (4)

You only need one high-torque digital on the rudder, like that 5955, 8711, or Futaba equivelant. It will be more than enough. You don't need a choke servo at all and don't need a servo for the killswitch if you go with a Smart-fly, RCATS, electrodynamics, or similar electronic kill (I prefer the Smart-fly). These types of kill switches, or at least the Smart-fly, are lightweight, solid state, fiber-optically controlled(means no ignition noise can be transmitted back to the receiver), and will kill the engine if you lose total receiver power. The same can't be said for a choke servo or servo-operated kill switch

The receiver can easily handle the servos, that's not what you need to be concerned with. What you need to be concerned with is providing enough power to them. One switch with one plug going into the receiver is NOT going to be enough. You need a minimum of two power leads going into the receiver, and I recommend more. I am running 8 servos total on my 35% into a total of 6 ports on my 10 channel receiver, plus my Smart-fly ignition kill. There are 4 remaining ports and they are all filled with power leads from my batteries.

Marcos Nieto

Hi guys...........thanks for your input. The only other gas plane I have is a 1/3 Pitts/ZDZ 50 NG with a standad kill switch servo driven. Not much experience on gas planes.
One question on the Smart-Fly switch...How can it kill the engine when there is no power failure on the receiver??

Marcos

reyn3545

The smart fly system kind of sits between the receiver and the ignition for the engine. its a two-piece system, with a fiber optic wire between the two pieces. If the piece on the receiver end senses a loss of battery power, it will kill the fiber signal to the other end, which will cause the ignition to shut off.

This "loss of battery signal" can be caused either by a dead or failing battery (safety feature), or if you set a radio switch to the particular receiver channel that the smart-fly is attached to... you can kill the power going to that switch, causing the smart-fly to cut ignition power... no moving parts or weight like a traditional servo, very limited battery drain, and overall a much more dependable, safe setup. Many RC fields and virtually every competition event requires electronic shut-off systems.

The down side of this type of setup is that you'll probably need at least a 9 channel transmiter and receiver, given all the other channels you want to set up with dedicated controls for each aileron and elevator.

But, it sounds like you had a channel and servo planned for a cut-off servo anyway, so you should be in good shape.

You can get a much better description of the system by going to http://www.smart-fly.com/

There are certainly other systems, but this is probably the most popular.

Marcos Nieto

What would be your choice of bat pack and Rx switches?? I was considering a pair of ZDZ failsafe ignition switches as they come as stock switch with the newer engines. In that case I'll have the same switch in Rx and ignition.

Marcos

reyn3545

I think all "major" brands would be a good choice... staying with ALL one brand should certainly give you some added piece of mind.