bodywerks

My Feedback: (4)

I didn't, and most people never will. I put a wattmeter in-line with the battery and hand stalled the servo. I only mentioned this because it shows you that two high powered servos will power quite sufficiently through a Y-harness and into one output of the Rx under normal use.

sillyness

My Feedback: (25)

Try plugging a large NiMh or LiIon batt to a discharger and discharging at 3 Amps... I did this on my ICE charger (not thinking) and the standard connector got wicked hot in seconds. Heat equals resistance, and resistance equals voltage drop, and voltage drop may equal rebooting a servo or RX. I don't care if the high amp load is only a second or 2... the resistance is still there. I run a Fromeco system... Deans Ultra plugs and 14 gauge wire from battery to reg, then 3 power outputs from the reg to the RX... keeps the voltage up (1/3 the resitance in the system). I love it.

Happens all the time, especially to guys trying to minimize their servo count. It's called blow-back (I'm sure you've heard if it). All the stories you hear about the difference guys feel when adding another rudder servo... that's cause they were initially on the verge of stalling.

sillyness

My Feedback: (25)

Here's the setup I'm putting in my next plane. All 5955s (got a good deal) except throttle and choke. Fromeco power system. 2 x Muiltiplex IPD RXs. No matchboxes. No Ys. No power boxes or other battery widgets... just simplicity in action. I have an SWB self adjusting rudder tray for the 2 rudder servos (no programming required). The ailerons are split in the middle... they will be mixed to move as one. This prevents any binding or locking of an entire aileron.

Left RX

1 Throttle
2 Power
3 R Elevator
4 Rudder
5 R Inboard Aileron
6 L Outboard Aileron
7 Power
8 Power
9

Right RX

1
2 R Outboard Aileron
3 Power
4 Rudder
5 Power
6 Power
7 L Inboard Aileron
8 L Elevator
9 Choke

rc bugman

My Feedback: (30)

sillyness,

Is your single point of failure now your Fromeco power system? or are you using 2 Fromeco power systems?

Elson

bodywerks

My Feedback: (4)

No. His power system is redundant.

sillyness

My Feedback: (25)

2 power systems. 2 x SuperRelia Regs with 3 RX leads each, 14 gauge wire on the batts and reg inputs, and 2 x Fromeco Peerless 2400 mAh batteries. Total weight, 10 ozs for the enitire power system with switches (measured by me)... much less than a couple 4-cell NiMh packs plus switches, or any power box setup.

On the Powerbox/Isolator topic... a lot of folks like the power box because it eliminates matchboxes... I've elimintated them with careful planning. I prefer to have 2 seperate regs that I know for a fact are electronically isolated, not a magic box I haven't seen the schematic for. Some like the powerbox for neatness... well I actually have fewer wires than required for a power box. For a single RX with a power box, 10 wires are required to connect the RX to the power box, then you have the 10 servo wires plugged into the power box. My system uses 6 wires to connect 2 regs to 2 RXs for power only, then the 10 servo leads directly from the RXs... that's 4 less wires, and and 20 less servo connections (14 less total connections if you count the 1 sided power connections that are soldered to the reg) to come loose or develop noise/losses.

Anyway, that's my power system of choice.

sebo

This isn't in response to anyone in particular. I have been following this thread and have decided that I will go with 2 receivers in my Hostetler Cessna 150. I have about 5K in this machine and I like the idea of being able to save the plane in a receiver out condition. I have experienced a receiver out condition 1 time over the 30 years that I have been flying. It must have been a crystal because as the plane flew away from me, I kept giving it right aileron and eventually, it quickly rolled on to its' back. I watched as it slowly went into a shallow dive. Since it was flying directly away from me I followed it on foot and found it splattered on an old abandoned runway of a small airfield. Sounds appropriate, doesn't it. I put it in a plastic bag, sent the entire radio back and got it back in great shape.
That is my story. Thanks for making me think about 2 receivers and showing me how to hook things up. Last night I ordered about $200 worth of equipment to do this (receiver, 2 batteries - one for backup), a Jomar battery backer, 2 more switches (one for each battery) and little wooden receiver boxes.
So, to do it right, if you don't already have the stuff at hand, it takes about 2 hundred bucks. But, to possibly save a 5K aircraft, it is still cheap insurance.

Darrinc

My Feedback: (5)

Nothing is totally safe, it just matters where you want to pend your money. The plane will die, one way or another. I just put the money I would spend on all of this stuff toward another plane, but thats me.


My favorite story is a guy I knew had double everything, a powerbox and all the other things you could buy. He truely spend a small fortune on all of the extra equipment.

His wife accidentally ran it over with their big truck. Crushed everything, powerbox, engine and all.

Total loss!

sillyness

My Feedback: (25)

I would reconsider the Jomar unit... it's a single point of failure.

As for spending your money... I saw your setups and they are simple and nice and I hope you have continued luck with them. For me the issue isn't money, it's time. If a redundant system can extend the life of one airframe from 2 years to 4 years, well then it is well worth the saved hours of labor, etc to me. I hate building. The planes fly beautifully as I set them up, and I feel safer around them when they are running. I also don't do a lot of 3D right close the the ground... it's more challenging higher anyway

mglavin

My Feedback: (31)

Kind of depends on how you setup your model I could do it with less connections than your describing above with a servo interface with the same number of servos. In any event the only additional wires are those that are routed to and from the RX and interface. And then you can subtract the connector set at each battery and regulator and then you could also loose the six power feed wires you mention with your setup. So I loose eight inter-connections immediately with a servo interface with onboard regulators. Emcotec and PowerBox interfaces have isolated regulators with short circuit protection too. If one regulator or battery fails the model continues to function across the board without power issues. You can also use two RX's on these interfaces if you please.

Another consideration is the wires that plug into the RX only carry the control signal to the interface. Power is routed directly at each servo and is isolated from each servo/port with signal amplification/conditioning and short circuit protection.

Not everyone has the ability to mix four aileron, two elevator and two rudder servos. Additionally most Asian radios create software frame rate lags when employing multiple mixes so control output response timing lags/suffers in some cases. Some are worse than others.

While your system is sound you don't have a redundant power source to either regulator. I’d like to see more battery capacity with Lithium-Ions. The 2S 2400mAh’s Lithium’s are not redundant sources as are 2S2P 4800’s with twice the ampacity.

sillyness

My Feedback: (25)

Don't need to mix the rudder servos in a self adjusting rudder tray... just plug them both into channel 4 on opposite RXs. You are right though... you need at least a 9 ch radio, though I'm thinking that someone flying 35% and larger aicraft probably at least has a 9303.

The bigger batts add 7 ozs total to the plane. I don't need the capacity... I never do more than 5 flights between charges... time limitations. At IMAC meets I bring a charger to field in case it's needed.

As for redundant power, I didn't want to bring this up, but I've been running a fused jumper (power leads only) between the 2 RXs... either batt or reg can fail and I keep the whole plane. Not sure if I will continue using it... still thinking. I think I'd be a lot more concerned about the single power source for the RX in the "other" setup.

sebo

I'm hoping that with one Jomar unit and a backup battery for each receiver that both Jomar units won't go at the same time. If they do, I'm up the creek without a paddle. Thanks for the input.
I feel that you guys have taught me a lot.
Thanks, Ron

mglavin

My Feedback: (31)

I agree you don't need the capacity so to speak BUT you do need the ampacity. Two 2400mAh Lithium-Ions can deliver about 9 amps. When your model is hungry for more they go flat in a hurry. A model with eight 5955's can consume in gulps upwards of 20amps during aerobatic routines. Voltage degradation at extremes is easily 1V or more even with robust systems. I have seen the voltage fall off the chart with my programmable electronic load when I drop the hammer on Lithium-ions. IMO 7ozs is a small price to pay for redundant power to the regulator and twice the system power on tap.

The fused jumper has proven itself for many…

What single power source are you referring to in the “other� setup? This is not plausible to the best of my knowledge.

budgetdude

My Feedback: (6)

On the fused jumper could'nt one side conceivably smoke the other side? What size fuse do you use.

sillyness

My Feedback: (25)

The only way one side could smoke the other is a dead short on one side... that's why the fuse is there. It's a 7.5 Amp fuse... just a guess, but it should work.

Yeah, but my plane is a little heavy out of the box... need to save weight where I can. Kavan wheels, 2400 batts, and light axles, and no wheel pants knock off a pound. Also, the new Peerless batteries from Fromeco have much greater Ampacity than their Relion predecessors. The can really give up the juice and not work too hard.

As for the 5955s drawing a lot of current... yes they do when they are stalled. But, my plane is "over servoed"... any metal geared servo is expensive and I got a good deal on the 5955s so I'm using them everywhere. In theory, my plane should draw the same current as one with 5 5955s (one on the rudder and each aileron)... current is a response to servo loading, so if the servo loading is cut in half by 2 servos, then the current should be almost cut in half per servo. I ran a single 8611A on each aileron of my other 35%, but I tried someone's with 2 per side and the diffrence was very notable... better snaps, crisper response... gonna do 2.

Darrinc

My Feedback: (5)

Wow, I am running a 1800mAh Li-Ion pack with five 5995's on my Cap. Here is my simple setup on my Yak, four 5945's and a 5735 on rudder witha HS 55 on throttle. The 4 cell pack is for tail weight btw.

The Yak flies like a foamie at 21.6lbs!!!!!

On it's third year!!!

Just sold it and I am sure the guy will have many more years with it.

sillyness

My Feedback: (25)

What Yak is that? I'm not aware of a composite Yak that's been out for 3 years[sm=confused.gif]

mu2driver

My Feedback: (15)

I have been following this thread as well...wow some great info here guys!!!

I've been using all types of systems in my planes, none are setup the same, from single to dual rec. from Duralite Power Box to Smart-Fly Power Expander, to just twin Reciever's with a split system, also a single rec running all 9 servo's in a 35%...

There is No perfect system, however there are many ways to make a successful system that will be redundant as well as reliable...

I use to be convinces that a Dual Rec is Best...untill I went to the Latest Jet Rally and watched all the Jet's some 12k worth...All with a single reciever, some with power boxes...the common link was 2 switches 2 batteries...I said if these guys are trusting there stuff to a single rec, maybe I need to revisite this..

My latest setup is custom, Fromeco "peerless" 4800's, through SmartFly SSwitch's "deans connectors, Fromeco Regs into the Power expander. each servo "14x 8611a" has a custom made to length extension straight to the Expander, there are NO match Box's, all Servos were paired with SWB metal arms. I get awesome range, on ground and in flight..60 flights strong, I will however take out my reciever after 200 flights which should be by the end of January and send it in for service...

To each his own, but if you fly it, it will crash! Just a matter of time, we as diligent assembler's/builder's try to minimize the cause of failure...

OnTheEdge

Turbines don't tend to vibrate like our gas pumpers. Vibration, heat and moisture are the worst enemies of electronics. We don't have to worry much about the latter of the two but vibration is certainly a concern.

Just a thought...........

mu2driver

My Feedback: (15)

Viberations are very harsh in these gasers...

sillyness

My Feedback: (25)

Also, there ususally isn't enough room in a jet to set up a 2 RX system with adequate distance between RXs and antenaes... 2 RX are great, but you still need to do it right to make it work for you!!!

Darrinc

My Feedback: (5)

As of tomorrow, my 2.6m Comp Arf yak will be 3 years old. With only one rx, one battery for rx, one 5945 per aileron, one HS 55 on throttle and one 5735 for rudder servo. Plus no regulators.

But then everyone told me it would not work.

Happy Birthday!

mu2driver

My Feedback: (15)

Yeah Darrin...it just wont work man, it just cant be done...

How many flight would you say you have on it...?

rc bugman

My Feedback: (30)

Hi,

Dual rx setup is comparable to the air bags and seat belts in your car, whereas careful setup, dual batteries and dual switches is like a defensive driving course.

As long as you don't crash, you don't really need the air bags or seat belts. The same is true with dual rxs. As long as you don't have component failure, you will never need the dual rx setup where each rx controls a side of the airplane.

I have never needed the air bags or seat belts in my truck or car, but I still buckle up before I start driving. I have had several receiver failures and the dual rxs have saved the planes.

Like seat belts and air bags, dual rxs is a strategy to plan and be prepared for failure. Hopefully, you will never need them.


Elson

Darrinc

My Feedback: (5)

Hundreds! Joys of depoying, when your home, it's flying time!