Powerbox vs duel recievers on 44% extra

[FastnLow]

Building a 44% extra 330s from giant composite models. Powerbox or duel recievers? Running 8611a's all around 13 in total. Deal with duralite batteries already. Just lookin for some insight on the power box only, have run duel recievers for years and have faith issues runnin only one.

[Mudsurfer1234]

We're putting a powerbox in a 3W Yak, and from what we've learned about it so far, it seems to be perfect. I like the idea of the power going through it rather then the receiver, and it has 24 servo ports, 3 on each, and some extra.

[notorious_benny]

I got my first powerbox yesterday in the Mail. Its a smaller version for use in a 2.6 Yak 55. I havnt flown with it yet but I already like its features. The sensor switch is fantastic! It is the most failsafe switch I have seen yet. ( I was running fromeco regswitches before)

In the instructions to the powerbox it states that you can use two recievers through the powerbox. So if you want to try a powerbox you can and run your two rx's as well.

The version I got can run 5 channels, you could plug in three from one rx and 2 from the other. But for a bigger plane you might want to go with a larger powerbox.

[260Kid]

Let me share this. At the begining I wanted the power box from duralite and duralite batteries and everything. Ive found right quick it was better off for me to go with smart-flies power expander and turboreg. To me it is just a solid setup if you have matchboxes. Duel recievers is also a good way to go. Just for me I think the smart-fly products are great products to use in a plane like this. Ive watch the tucson 2005 shootout video and look at the setups and some were just tooo complicated inside. My setup ended up being a nice solid setup. Plus less $$$$$$$$$$$ Just thought I would share my experience.

[excelpoint]

FastnLow, I run two Rx;s in my 44% Giles with out any probs, they plane is split down the middle.I only run 8 servo's(8611's) as I have the elevators and rudder massed balanced,plus a throttle and choke servo, seems to work really well.

[adrian]

i will never fly any big plane without a powerbox/smartfly/emcotech - new generation digis drawing 3 amp through a receiver, is a plane death wish - fact - dont try to save small money to loose big - tested it a few times

[forgues research]

	Quote: Originally Posted by excelpoint
	FastnLow, I run two Rx;s in my 44% Giles with out any probs, they plane is split down the middle.I only run 8 servo's(8611's) as I have the elevators and rudder massed balanced,plus a throttle and choke servo, seems to work really well.

Untill a servo freezes and feedsback to the receiver, then what..

Fiber OPtic extensions is the only way to go , no long signal leads, lighter, and full signal voltage on the servos.

EVO 150 (of course)
Roger

[Kiwi]

Stacey,

Adrian hit the nail bang on the head with the statement regarding the use of Powerbox-expander-emcotec etc.

There is absolutely not a snowballs chance in hell that I will ever run a plane bigger than 25% without some kind of power management system.

I have a video nearly ready and hope to post it this weekend on some experiments I done trying to burn out a smart-fly system. I think it will answer some questions for a lot of people who want to build 35% plus planes and want a failsafe setup.

First of all when we talk about fail safe we need to understand a few basic premises. One is that if we are trying to make a system that will cope with servo failures or an electrical fault downstream from the power -x-y- system then we are talking the impossible. What I'm saying is that if you strip or jam a servo in any position at all then your going to loose your plane. The only thing we can build redundancy into is the Battery setup, the RX setup, regulator setup and switches. After that there is no redundancy.

Look at it this way.
Twin battery setups provide redundancy only in the case of a cell failure or a cable failure. If you have only one power management system being feed from seperate battery sources it still relies on one power management system. All roads lead to Rome so to speak.

True regulator redundancy can only be acheived with two seperated regulators and then they cannot feed a common distribution center as a short circuit or any failure on the board will take both of them out of action anyway. Same as the battery scenario above. All roads lead to Rome.

Dual RX's will give you half a plane to control. If one rx fails and the controls on the failed RX do not failsafe to neutral then your planes DOA on arrival with planet earth. If you loose power and the control surfaces float then your going to be dead lucky to control it anyway.

The SWB rudder tray can tolerate a locked servo so if you feed two rudder servos off one RX and the other two off the other RX you have true redundancy only on rudder.

However I think it all boils down to what do we want to have redundancy on. If you say everything then thats impossible.

If you say power supply thats possible.

If you say receivers then its difficult as you really only have half your plane to control in the event of an rx failure. You will loose almost everything if the rx contolling the throttle servo is the one that goes on you.

I could go on for hours about the possible setups, failure scenarios etc etc. However I think it all boils down to personal taste.

If I was to build my 52% EDGE I would likely do something like the following. Please the brand I use is what I'm comfortable with, you can use what ever and get the same result.

Two Smart-Fly power expanders with super regs to each board. 4 x 2700 Fromeco packs feeding the twin regulator setup. That gives me dual redundancy on both rx systems.

Twin Seiko servos on rudder using the cable system so if one goes out the rudder is still functioning. The battery system for the rudder is seperate from the the other servos.

Crossed servos on the ailerons, elevator so if one rx goes down the second drives through the dead servo but retains control. You have to assume here that if the rx goes down on you power is lost to the affected servos so the good one can still drive through it. That is only an assumption remember. If it failsafes or holds then were dead as well.

Throttle servo, engine kill system etc on a seperated power system running off the ignition batteries. The connection to the rx is via a fiber optic servo driver so there is zero electrical connection between the two RX's and the engine. The smoke would also be driven from the ignition pack and fiber optic as well.

Using a system like that I just dont think you could have any better redundancy or failsafe.

Is it really absolutely redundant in every aspect. NO! But it is as close as you will ever get.

Hope you understand some of this.

Kiwi

[Lomcevak]

Here is what you need for twin receivers...

[forgues research]

	Quote: Originally Posted by Kiwi
	Stacey, Adrian hit the nail bang on the head with the statement regarding the use of Powerbox-expander-emcotec etc. There is absolutely not a snowballs chance in hell that I will ever run a plane bigger than 25% without some kind of power management system. I have a video nearly ready and hope to post it this weekend on some experiments I done trying to burn out a smart-fly system. I think it will answer some questions for a lot of people who want to build 35% plus planes and want a failsafe setup. First of all when we talk about fail safe we need to understand a few basic premises. One is that if we are trying to make a system that will cope with servo failures or an electrical fault downstream from the power -x-y- system then we are talking the impossible. What I'm saying is that if you strip or jam a servo in any position at all then your going to loose your plane. The only thing we can build redundancy into is the Battery setup, the RX setup, regulator setup and switches. After that there is no redundancy. Look at it this way. Twin battery setups provide redundancy only in the case of a cell failure or a cable failure. If you have only one power management system being feed from seperate battery sources it still relies on one power management system. All roads lead to Rome so to speak. True regulator redundancy can only be acheived with two seperated regulators and then they cannot feed a common distribution center as a short circuit or any failure on the board will take both of them out of action anyway. Same as the battery scenario above. All roads lead to Rome. Dual RX's will give you half a plane to control. If one rx fails and the controls on the failed RX do not failsafe to neutral then your planes DOA on arrival with planet earth. If you loose power and the control surfaces float then your going to be dead lucky to control it anyway. The SWB rudder tray can tolerate a locked servo so if you feed two rudder servos off one RX and the other two off the other RX you have true redundancy only on rudder. However I think it all boils down to what do we want to have redundancy on. If you say everything then thats impossible. If you say power supply thats possible. If you say receivers then its difficult as you really only have half your plane to control in the event of an rx failure. You will loose almost everything if the rx contolling the throttle servo is the one that goes on you. I could go on for hours about the possible setups, failure scenarios etc etc. However I think it all boils down to personal taste. If I was to build my 52% EDGE I would likely do something like the following. Please the brand I use is what I'm comfortable with, you can use what ever and get the same result. Two Smart-Fly power expanders with super regs to each board. 4 x 2700 Fromeco packs feeding the twin regulator setup. That gives me dual redundancy on both rx systems. Twin Seiko servos on rudder using the cable system so if one goes out the rudder is still functioning. The battery system for the rudder is seperate from the the other servos. Crossed servos on the ailerons, elevator so if one rx goes down the second drives through the dead servo but retains control. You have to assume here that if the rx goes down on you power is lost to the affected servos so the good one can still drive through it. That is only an assumption remember. If it failsafes or holds then were dead as well. Throttle servo, engine kill system etc on a seperated power system running off the ignition batteries. The connection to the rx is via a fiber optic servo driver so there is zero electrical connection between the two RX's and the engine. The smoke would also be driven from the ignition pack and fiber optic as well. Using a system like that I just dont think you could have any better redundancy or failsafe. Is it really absolutely redundant in every aspect. NO! But it is as close as you will ever get. Hope you understand some of this. Kiwi

Yikes, have you any idea how powerfull the Seiko is , I have only one on my 52% Edge, and it is plenty powerfull at 1800oz of torque

Roger

[Kiwi]

Roger,

Yep, I have two planes running them. I would hazard a bet that the 52% would suffer from rudder blow back in a true tumble or fast gyroscopic manouvre, you will be surprised at what it takes to hang that thing out positively in the breeze.

My PITTS has a total of 1300 in lbs on elevator and know it suffers from blowback. You can see it and feel it. Thats using two 2700 lipo packs with a powerbox setup.

Kiwi

[Kiwi]

Lomcevak,

I have seen a lot about the Emcotec but I think it is nothing like a true backup system when you study it.

For example the only way it will let the second RX take over is if you loose power to the first RX.

If say the crystal falls out it does nothing and you ride your system into the ground anyway. If you get interference on that one rx or any sort of internal RX failure it does not know. You still end up with a good BBQ in the end.

I have heard you can run two frequencies and two radios with one being the master but that seems a big overkill.

I am sure at has many advantages and great features but like everything there is never a true and final reserve system to save your bacon. No matter how much we try in this hobby I doubt we can make it impossible to crash. If we could they would be doing it on full scale planes everywhere today.

I agree with reserve battery systems, failsafe switches, even twin rx's if it makes you comfortable. But you cannot overcome every possibility and probably the greatest one of all is pilot error. That includes poor maintenance as well.

Kiwi

[ShortBus]

	Quote: Originally Posted by Lomcevak
	Here is what you need for twin receivers...

What will that chick do for my Recievers? lol

[gixxer]

	Quote: Originally Posted by Kiwi
	Lomcevak, I have seen a lot about the Emcotec but I think it is nothing like a true backup system when you study it. For example the only way it will let the second RX take over is if you loose power to the first RX. If say the crystal falls out it does nothing and you ride your system into the ground anyway. If you get interference on that one rx or any sort of internal RX failure it does not know. You still end up with a good BBQ in the end. I have heard you can run two frequencies and two radios with one being the master but that seems a big overkill. I am sure at has many advantages and great features but like everything there is never a true and final reserve system to save your bacon. No matter how much we try in this hobby I doubt we can make it impossible to crash. If we could they would be doing it on full scale planes everywhere today. I agree with reserve battery systems, failsafe switches, even twin rx's if it makes you comfortable. But you cannot overcome every possibility and probably the greatest one of all is pilot error. That includes poor maintenance as well. Kiwi

http://www.dodvideos.com/emcotec-twin.wmv

Actually, I believe the Emcotec will only switch over if the failsafe kicks in. At least that is what I got from Joe Hunt in this vid. I do not have any firsthand knowledge with this unit(yet), but like I said, watch the video.

[Lomcevak]

Hi Kiwi,

personnally, i don't use the DPSI twin. I use the single one with one receiver only I have this set-up on 2 planes and never had a problem...so far...


Regards