Does anybody use a twin reciever setup in their aircraft? I was speaking to a large model dude the other day and what they seem to do is have a twin reciever setup with flight controls crossed accross each reciever. i.e left aileron on RX 1 , right aileron on RX two, right rudder of RX 1, left rudder on RX 2...... you get the idea. They seem to go for PPM recievers as well , can you not do this with PCM ???
Couple this with a battery backer and you are well on your way to having a fully redundant airborne system?


I got my Reaper up for the first time last weekend, this was my first turbine flight, to say I was nervous was an understatement but by the end of the weekend I was chugging around nicely, can't wait to open that P80 up.....

Nick

Im using dual PCM rx's in my 40%, so that works. I have flown a 40% on one rx, (one aileron, one elevator, throttle) and it flew better than I thought it would, cant speak for how a jet would fly, but it just might work BUT, I see/hear of more single rx setups..

Hi John,

I'm confused by your statement. Why would you expect the plane to fly any differently on one Rx, as opposed to two Rx?? Or did you mean something else?

Thanks,

John

I expected it to be hard to manage on half of the plane working, but it was actually not bad, a little slower on moving, but still easily flyable. This being in a 2 rx system where each rx runs half of the plane.

Everything I've read on redundant Rx systems is that for some unknown reason, they seem to have a reduced range and more interference problems than a single Rx.

Hi Nick

The main reason for the "twin receivers" in the big planes was the major current draw due to all the digital servos. 6 aileron servos, 4 rudder servos, 4 elevator servos all digital. It then made sense to do a redundant receiver setup. In the jets we are probably getting there with the bigger jets. Believe me that if you get "lockout" on one receiver, you will get it on both receivers as well. Powerbox and Emcotec and some others make boxes to handle the higher current required by the number of servos used in these big planes. And now the argument begins about - one more thing to go wrong!

My 2c worth!

Regards

Zane

Nick,

I have flown giant scale with redundant system's for years. A redundant system for you jet is a great idea if you are concerned about system failure. Keep in mind the ECU connects to your rx as well, check with the manufacturer for details on a dual rx setup. A true redundant system would consist of two batteries, rx's and two servos for each channel using something along the line of a matchbox. This could prove to be a challenge, but can be done. I have seen servo failure on a few occasions, one locally that resulted in the loss of a 40% Cap. In addition battery failure has proven to be a common problem. JR systems wil allow you to plug a an additional battery into any open channel, giving you a back up battery. I have personnally had a new JR rx fail on the first flight, thanks to the dual rx set up I landed the plane. A redundant system can be a challange when chasing a problem. I currently fly my Avonds F-15 with one rx and a two batteries. Hope this helps.

Nick,
I'm getting a Super Reaper ready - where did you put the center of gravity balance point?

thanks,

Larry Brannan

Larry, most of us are going with the recommended 530mm forward of the TE, but you can go up to 570mm comfortably.

Mine has the CG at 570mm with a full load of fuel and goes back to 530mm when I am allmost dry, no real noticeable trim change.

I actually had my SR set up originally with two 6 channel recievers running together but that was due to the servos I was using not responding well to a "y" harness (digital Hitecs and Airtronics pcm receivers) when I went to my current JR 10x setup I am back to one receiver. I didnt notice anything abnormal with range, etc.

AJC

Yeah I suppose that if it were truly a benefit then everybody would be flying around with this setup, and they don't seem to be, I shall ponder.....
It is only really guarding against dodgy electronics and how common is that on a modern integrated circuit, I do agree with you Zane, its just one more thing to go wrong, I am trying to keep my installation as simple as possible, but I am very interested in building in redundancy.


Larry, I put my CG at about 535, and she is very stable in pitch but requires a reasonable amount on the nose down trim. I have managed to locate my fuel tank right over the cg so I don't notice any trim change in flight.

Cheers

Nick

Hi John,

OK, I misunderstood what you were saying! You meant flying the plane on one receiver after the second had died, and I thought you meant you were flying a single receiver airplane! Thanks for the clarification!

John