RE: Why does it always happen to the good ones??
 

Ya what he said:D


Ron:D

RE: Why does it always happen to the good ones??
 

Ron,
You have something to add to this thread. BOTH of you duralites in the Viperjet went dead on sat and you were a couple of minutes away from destruction had you not landed when you did. So does that mean we need three batts to be safe?? [&o]

V..

RE: Why does it always happen to the good ones??
 

maybe 10 batts Ron :D

RE: Why does it always happen to the good ones??
 

Vin,

I think a car battery may be needed.:D:D:D


Ron

RE: Why does it always happen to the good ones??
 

HAHAHA>..

and seiko servo's on anything bigger than 80" long?

RE: Why does it always happen to the good ones??
 

I would like to give you David and advise when posting if you want anyone to care for your oppinions and that is to be a bit more humble. To get anyway with your points you need to be able to express your meanings in a way so that people might consider what you are saying. Your post is just making people ignore everything you say as you are scolding on someone that is known to be one of the greatest guys in this hobby. He is a good flyer, yes, but from the little i know him he is even a much greater person.

My technical point here is that there is always a fine line between added complexity to make redundant solutions and simplicity. Usually the best solution is something in between. As complexity makes other problems that sometimes are hard to track or discover. To much simplicity might not be up for the task.

I know personally of two airplanes that crashed using weatronic that probably would not have crashed using a simple one battery one receiver solution. The case here was that with a previous version of their software they did not limit the scanning function to only be activated up to 15 seconds after power on. The motor on the aircraft got a loose bearing that caused a lot of radio interference, this did not cause the weatronic to failsafe as the ribbon cable picked up the noise and the weatronic did go in scanning mode. Now a normal single receiver would have gone into failsafe and idled or stopped the engine which would have stopped the radio interference and the plane could have landed safely (most probably).

So, how safe are you if you just plug two batteries to your receiver and one battery looses lets say two or three cells. The amount current that is going from the good battery to the bad could be substantial and it could also easily drain the good one. So then we need to apply more gadgets in order to isolate the bad battery from the good one. Like a regulator of some kind.

Then you add a powerbox. Which is a highly complicated box, and is perfect as long as it works. But the number of single point failure components you add to the aircraft when adding a powerbox is substantial. Yes, you have isolated dual redundant power supply AND you also have maybe 100 more single failure components and you need to thrust the compatabillity of the powerbox with your other components. Which was an issue discovered by customers when the new FASST 14ch receiver was out due to signal voltage.

My point is that it is not so easy always to make the right descission on what is the best and safest solution, Personally im not sure. Im having the smallest, simplest powerbox in some of my jets and some others i run a couple of A123 into a duralite regulator (one each). A another one i simply put two NiCd directly to the receiver. It has all worked great for me, but there is a ton of other variations that works great too. The most important thing i beleive is that you are familiar with the solutions in your aircraft cause misuse is a big factor in crashes. The one crashed i have had was a structual weakness from the factory that i did not understand before the jet was in the ground. From what i see with the number of new cheap ARF's coming that might be the biggest risk there is right now. And we dont want to run biplane jets for the sake of redundant wings do we??

RE: Why does it always happen to the good ones??
 

I remember my first experience with using two batteries in a 40% Aerobatic plane a few years back. I used a product called "The Battery Backer". Product was supposed to isolate each battery from the other so if one failed the other would continue to power the plane. It worked great, until one day, the Battery Backer failed! Inspection after the crash showed two fully charged, working batteries, one dead Battery Backer, one dead 40% Aerobatic plane!

Moral of the story: SHAIT HAPPENS In this hobby, you'd better get used to it, cause any electronic product, made by man, can & will fail! Although, with me it's the electronic brain to thumb connection that usually goes first:eek:

David S.

RE: Why does it always happen to the good ones??
 

Ali,

I know you well enough that I can say this.............................. THAT WAS AWESOME!!!!!! (just dont do it again) ;) I know that you will move on and do a better bird fo sho!! We need more guys like you that can keep a positive attutide and understand that this is ONLY a hobby.

RE: Why does it always happen to the good ones??
 

I watched a very expensive, very beautiful jet go in this weekend because the engine quit. Guess it should of had two engines in it. It having 2 powerboxes or 10 batteries or 3 receivers wouldnt have kept it from its demise. Theres still just one ecu and one turbine fed from one fuel pump and one fuel system. We still dont know why 90 percent of engine flameouts happen.
I flew my F100 for about three years with one duralite battery and one regulator and never had a problem. I decided to upgrade the elevator servos to 8611's and lost the jet shortly after when the regulator failed. Needless to say, I switched to Fromeco batteries, switches, and regulators. I run the dual switch, 2 batteries and 2 regs on everything and now with 2.4 I feel more confident than ever with this setup. It might be overkill, but I enjoy the peace of mind and the ability to fly all day without charging. I really like the Fromeco line. Good stuff.
Ali,
Sorry to hear about the crash. All you need is more abuse. David is way out of line.
Sorry man
Scott

RE: Why does it always happen to the good ones??
 

And I thought it only happened to me! :)
Greg

RE: Why does it always happen to the good ones??
 

In my 30+ years as a human being I would say, as an American, that sounded a little like...................... Rodney sums it up for me.

RE: Why does it always happen to the good ones??
 

LOL Nice Ian could not have said it better myself :D


Ron

RE: Why does it always happen to the good ones??
 

Hi Ali,

Really sorry to see your great hunter go in. [:o]I know what your saying about David and a few other guys in the UK jet scene. If I remember correctly wasn't David the guy at the UK jet masters that put a T33 model in the top off the full size hangar. [>:] (I could be wrong)

The only guy that helped me when I was still living in the UK was Mark Leaveslay who is a great guy and he really helped me when I purchased his JPX powered starjet when I was still only in my teen's. Paul gray and Joe helped me also.;)

Kind Regards, John Blake.

RE: Why does it always happen to the good ones??
 

Ali, I just wanna say that there is no better ambassador to the world for jet modeling than yourself. You keep jets in the forefront of the hobby around the world which is more than 99.9% of the guys out there, we're lucky to have you and I am proud to know you buddy.

Can't wait for the F-5 maiden pics too!! Keep it going just like you are[sm=thumbs_up.gif][sm=thumbs_up.gif]

RE: Why does it always happen to the good ones??
 

wow... mm

ok let me have a go then...

2 weeks ago we where on holiday in France , and as i told ALi we had a failure on a 12X receiver ,luckely this was BEFORE the start.
this Flash was driven by a Emcotec BIC with twin power inputs..
the day before we did over 6 flights with no problems , this flash has about 40 flights on it.
after i got home i inspected the receiver wich was weird , the power all over the receiver was still there.
the jetcat ecu was powered but signal failure , all not working they had power but no signal.
leds on RX blinking.
and a smell of a shortcut.
after opening the RX i found a small smd part prob. zener or other diode or spike filter that was blown or shortcutted.
anyway because it WAS shortcutted the complete MCU of the board was left unpowered , where the main power was still connected since it bypasses the RX completely.
after speaking to my Friend Carsten , i removed the broken part and the receiver started working again.
why it failed in the first place we have absolute no idea , i checked power consumption and found nothing out of the ordinair.
we checked servo,s cables nothing we can do about it..
still as you can see on the picture this small 25 cent part caused a complete lockout on the system (DEAD).
no powerbox in the world that can save you.
still your strongest system is all related to the smalles parts..


and to take all illusions away:
this flash uses on 2,4 amps on max power usage. (snap on high speed)
nominal after 3 flights 250 mah on each battery.
average consumption 1,2 amps.


secondly i have sold 2 powerboxes to one customer on BOTH occasions failed.
one had a signal loss on channel 6 port one wich was a Left aileron on a ultra lightning , flipping from max to min try that on airborne ,it was found just for the start.
other powerbox was failed on one power channel , so no system is perfect.
still it is a great product..
i believe also in simplicity ,where i have indeed also always flown on a single batt with 0 problems.
at that time we did not even use a switch because of the vibrations these would fall apart after a small amount of time.

so even if you own a 2,4 powerbox with 50 battery,s it still has ONE TX unit ..

picture : green lines powers all the satelites and the small tx unit on top and the MCU.
on top corner is the bad boy , caused a complete lockout..

PS: if anyone from 'JR or spektrum tech service sees this.
can you share the part discription? i want to use it again and not spend 275 usd again..:D

RE: Why does it always happen to the good ones??
 

I fly one of my jet on only 5xAAA for the reciver (one reciver) and 1000mA for the pump, I have a battery watch on the reciver battery.
after start i check the batt watch - if it moves from the topmost green while banging the sticks i shut down and charge.
It's as simple as possible - and very few parts that can go wrong - it's as simple tank-start-check-fly, within 5 minues of arriving at the field.

Oh btw, did i mention the plane weighs 1500 grams, and has only 4 miniservos, and a kolibri :D
the thing is - consider the application before implementing the added complexity

a famous thinker once said " simplicity is the ultimate sofistication"

i see people all around fall for what i call the "bling-bling-effect"
- if it's sofisticated, lots of lights, usb interface, coloured alu, lcd-screen, chrome, lots of wires, then it must be good - right ?? :eek:

Ali - if you have weighed the alternatives, considered the risks, i have NO problems with you flying with just one pack in your jets.
i trust your abilities to properly weigh the risks against ease of service/simplicity.

Everybody yapping about multi powerboxes, several batterypacks, etc, are just that ... yapping.

RE: Why does it always happen to the good ones??
 

Well that seems to have stirred it up but Beave sums it up. Didn't for one moment think I was condescending about Americans its a phrase (go figure) you use. As for the corespondent who asked how much jet building, answer lots, currently 11 in the fleet.

And yes I did spin my T33 through a hangar roof, flew it rather too slow and flicked it pulling in a turn, pilot error, min, owned up immediately.
I guess, according to some of you guys, I am wasting my time installing Dual receivers, Powerbox Royals, Spektrum Powersafe receivers (and the manufacturers are wasting their time producing them !!) etc dual batteries, but I dont think I will pull them out !!

We CANT make things bullet proof , not possible in the real world, , BUT we can load the dice in our favour.

My sincere aplogies if anyone thought I was abusing ANYONE, just telling it as I see it !!

Fire away !!

Regards, David G.

PS For those who think that channeling TWO batteries through ONE unit such as a Powerbox etc is another potential source of failure then even that can be avoided. On several of my jets I have two batteries connected DIRECTLY to the receiver. One to the battery port, the other via Y-lead on a sevo port. That gives dual battery power without any futher complication and is a system recommended to me many years ago by Tony Frackiowak. I believe he was working for NASA at the time, at least 10 years ago, and that is the system they were then using to create battery redundancy on some of their miniature drones. He recommended it for my BVM F4 and I have used it on several models since with total success.

RE: Why does it always happen to the good ones??
 

Yes with your Weatronic system , all it needs is one guy who is on the same channel , gone is your double system..
seen that happen once.
its in the manual...

RE: Why does it always happen to the good ones??
 

I think the majority of us would never tell you that you are wasting your time. Some may suggest that they believe it to be overkill and that they would do it differently but in the end it is your decision. Most of us can accept that other people have different opinions and different ways of doing things but that doesn't necessarily make them wrong or dumb.

p.s. I am yet to be convinced that the dual receivers of Weatronic or the RRS system have much practical benefit in terms of redundancy. There must still be a single circuit that selects which receiver to use and if this fails you are still up s**t creek.

RE: Why does it always happen to the good ones??
 

cool so if one battery fails , the good one will make sure it powers the failed one then.. dont see really the benefit.
exept for more danger even to get a good spark.
that way will collapse the whole system

there is a even easyer system pre aged the power box and all others but was the basics for all of them.

first get 2 of these : http://www.microsemi.com/catalog/part.asp?ID=2222

solder them together
connect 2 battery,s to them
if one fails , the otherone will stay connected to the output channel , and will keep working.
the "shortcutted"one is dissconnected automaticly
and you have 6 amps contant power and 6 volts

RE: Why does it always happen to the good ones??
 

Hi
Daves point which I think is being slightly lost here is that we should always consider reinforcing the potential weak links in our aeroplanes. Batteries are a well known weak link especially the airborne pack because of the environemnt it lives in and the continuing varying current it has to deliver. Batteries prefer a steady current drain not spikes. Which is why Tx batteries generally last longer than Rx batteries.

Going down the route of multiple redundant systems is a choice the individual has to make based on the plane,the investmentand the risk. We have a saying in the Nuclear Industry ALARP. As Low As Reasonably Practical and that I beleive is what Dave is suggesting. We should always consider ALARP when cosnidering the weak links in the system. No system can be made 100% bullet proof but we can at least minimise the risk which I believe is the point is the Dave was trying to put over.

Redundacy always comes at a cost, increased complexity, increased weight or something else and this also has to be considered.

Even a dual battery system still depends on a potential single point of failure ( eg the change over mechanism) . Normally the potetial single point failure has a far higher ( several orders of magnitude) reliablity than the devices it is changing over.

In my profession I live by risk and redundancy otherwise things get very nasty very quickly. I use the same principal in my Jets. My Exocet has a single RX but dual batteries. Mainly because we couldn't shoe horn a Weatronix in the fuselage. My next jet will have both dual rx and dual battieries. God forbid it still suffers a failure than at least I will know I have done all I can and I have suffered the one in a million. ( then throw myself on the mercy of the wife).

I await the flak.

Mike

RE: Why does it always happen to the good ones??
 

Hi Mike,

Sorry to hear your wife knows about your jets.

RE: Why does it always happen to the good ones??
 

Hi Zack
She knows alright, She bought me one as a pressie.

M

RE: Why does it always happen to the good ones??
 

My thoughts:

First, we all know the weakest link in any full-size jet...there are two of them in every cockpit and it rarely changes the outcome. So much for redundancy!

Secondly, I think we missed the most important thing in Ali's comments..we can have a significant influence on newcomers to this fantastic sport depending on our willingness to help and our attitude. We could all take a lesson from Ali in this department.

Third, Chad should change the name of his store...Think of the domestic problems it causes when the wife sees those checks make out to "Sin City..." (Chad - thanks again for helping this newbie on the phone last week.)

Fourth, stop calling them "crashes." They are merely 'off-airport unscheduled arrivals.'

RE: Why does it always happen to the good ones??
 

What a great comment... lol... ;-)