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Old 02-15-2011, 10:13 AM
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Default Running CDI from RX

can I power an electronic ignition for a DLE 30 from the receiver? I will be using a 2s lipo for my rx power so I was planning on using a voltage regulator. Which kind would be best? Also if someone could comment on whether or not electronic noise entering the rx would be a problem that would be great.
Thanks for your help.
Old 02-15-2011, 10:53 AM
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Default RE: Running CDI from RX

tempting fate?
Running from the same battery already is considered bad practice due to interference coupling.
Old 02-15-2011, 11:22 AM
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Default RE: Running CDI from RX

Depends on which radio system you are using.

Some people are ALREADY doing this with 2.4ghz systems. Do some searches in this forum and maybe the giant scale forum.

I have never heard of anybody doing this with a 72mhz system. I think pretty much everybody would agree this would be a recipe for disaster.
Old 02-15-2011, 03:11 PM
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Default RE: Running CDI from RX

Anyone could do it. I have some very good radios but I can assure you it would never, ever happen in one of my planes. There's not a radio out there that can filter out all the EMI an ignition can generate when things go bad.
Old 02-15-2011, 03:14 PM
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Default RE: Running CDI from RX

I have been flying the Wike ignition battery eliminator/engine kill on one DLE 50 and one DLE 30 on PCM. The 50cc plane carries two 4.8V batteries & 2 switches into the receiver. The 30cc plane carries one 4.8V & one switch. Both I have been flying regularly for a year now. No problems.
Old 02-15-2011, 03:36 PM
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Default RE: Running CDI from RX

there was a huge thread about this on the FLY ING GI ANTS forum

Old 02-15-2011, 06:48 PM
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Default RE: Running CDI from RX

Pray it has 20kv of filtering capability.
Old 02-15-2011, 06:56 PM
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Default RE: Running CDI from RX

Ok well this is what I had in mind.

http://www.troybuiltmodels.com/items/WRCIBEFV2.html
It's a switching voltage regulator, kill switch, and noise filter all in one. What do you guys think. I am not sure if I am understanding this redundancy thing because in the event of a receiver pack failure, I would certainly want my ignition pack to fail with it

Do you think it would be adequate noise filtering?
Old 02-15-2011, 08:00 PM
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Default RE: Running CDI from RX


ORIGINAL: Fflier9

can I power an electronic ignition for a DLE 30 from the receiver? I will be using a 2s lipo for my rx power so I was planning on using a voltage regulator. Which kind would be best? Also if someone could comment on whether or not electronic noise entering the rx would be a problem that would be great.
Thanks for your help.
Take a look at Ed Alt's IBEC. Here's the link http://www.tech-aero.net/

This device goes between your RX and your CDI. It is a high end filter (practically eliminates RFI to the RX), has an optically isolated signal, has settable output voltage to the CDI, is a very safe CDI arming switch (on and off) from the TX, weighs around 2/3 oz with almost negligible voltage drop across it (saves the battery).

Will save the weight of the extra battery and switch (itself weighs very little) which should be desirable in 20cc and 30cc planes. However, the device is so convenient and safe, IMAC pilots use it on their 40% stuff.
Old 02-15-2011, 08:01 PM
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Default RE: Running CDI from RX

thanks for that, will be ordering one. [8D]
Old 02-16-2011, 03:27 AM
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Default RE: Running CDI from RX


ORIGINAL: Fflier9

Also if someone could comment on whether or not electronic noise entering the rx would be a problem that would be great.
Thanks for your help.
You ingored the recommendations of two of most knowledgable people on the Universe?Youdidn't even question why? I find it most interesting?
You can run a RCxel on 3.6 volts, one 1000 ma Lipo will give you three hours and weights almost nothing, four AAA Enloops gives 4.8 volts and weights next to nothing. I know there are people out there doing this with success and I'm sure there are many asking "What happen?" How much are you willing to risk?
Old 02-16-2011, 04:48 AM
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Default RE: Running CDI from RX

I didn't ignore their advice, I made an informed decision. There are many threads on this device, lots of people using it, and I couldn't really find any accounts of blatant failure. To me that says it's probably OK.

Sorry if I upset the hierarchy?
Old 02-16-2011, 05:00 AM
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Default RE: Running CDI from RX

It's your decision, but not only your risk, unless you fly alone.
The main rule in my book still is: "better safe than sorry"
Old 02-16-2011, 07:07 AM
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ORIGINAL: pe reivers

It's your decision, but not only your risk, unless you fly alone.
The main rule in my book still is: ''better safe than sorry''
Pe reivers
Before poo-pooing the device, try it. I think you will be impressed. Ed Alt, the designer, knows more about spurious RFI getting back to the RX than practically everyone around, on par with Dean Pappas. The man designs electronic systems for the DOD.

As far as safety goes, arming-disarming and fail safe set-up of the CDI via the radio, is much safer than getting to a switch by hand on the plane. Consider what happened to me last year, where the thottle link became disconnected. I simply shut the thing down remotely rather than have to run out a tank or take a chance landing at high idle. Which is more dangerous?

I fly with a group. I don't hesitate using mine. The risk is lower with it in my view than without it. And BTW-I've been flying RC since 1969...I think I know what I'm talking about too
Old 02-16-2011, 07:50 AM
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Default RE: Running CDI from RX

I dont do it, and havent considered doing it. But from a safety standpoint what if the battery goes bad in flight. with a separate battery and the receiver battery goes out, the plane could be headed for a crowd of people at full throttle. With only one battery it will drop like a rock with no engine running. A potential benefit.
Old 02-16-2011, 08:11 AM
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Default RE: Running CDI from RX

A lot of people are doing it, and have gotten away with it. Or have they? What has been the cause of some of those mysterious 2.4 lockouts? There is yet to be a definative answer to why so many perfectly good radios just stop working. I'll grant that a fair number of them have been from dumb users running batteries too small or flat, but not all of them. How about that plane that suddenly just went crazy in flight, or the loss of control on the ground? What was the cause? You can find 40 page threads on every forum talking about planes that are having 2.4 issues but few look at the entire electrical installation for answers to their problems.

I used to fly UAV's and now only handle the propulsion side with them. Pretty high end designs, with the best electronics suites that can be designed by what are true rocket scientists. What I know to be absolutely true is that our engines and ignitions can electronically swamp the best electrical systems made if a direct feedback loop is encountered. How do I know that? Because I've experienced it and done so with equipment far superior to anything some cheap Chinese electronics manufacturer is putting on the market. Yes, you can run a single electrical power source on your plane but once anything happens that interferes with the separation of electrical busses you're plane is dead meat. You traded safety and redundancy for a couple ounces of weight. Foolish indeed.

But hey, some people are doing this single source ignition thing and haven't been bit in the ***** yet, so it's all good, right? Like I said, you won't find it in my planes because I know it cannpot be defended against when the chips go down.
Old 02-16-2011, 08:23 AM
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ORIGINAL: Tired Old Man

A lot of people are doing it, and have gotten away with it. Or have they? What has been the cause of some of those mysterious 2.4 lockouts? There is yet to be a definative answer to why so many perfectly good radios just stop working. I'll grant that a fair number of them have been from dumb users running batteries too small or flat, but not all of them. How about that plane that suddenly just went crazy in flight, or the loss of control on the ground? What was the cause? You can find 40 page threads on every forum talking about planes that are having 2.4 issues but few look at the entire electrical installation for answers to their problems.

I used to fly UAV's and now only handle the propulsion side with them. Pretty high end designs, with the best electronics suites that can be designed by what are true rocket scientists. What I know to be absolutely true is that our engines and ignitions can electronically swamp the best electrical systems made if a direct feedback loop is encountered. How do I know that? Because I've experienced it and done so with equipment far superior to anything some cheap Chinese electronics manufacturer is putting on the market. Yes, you can run a single electrical power source on your plane but once anything happens that interferes with the separation of electrical busses you're plane is dead meat. You traded safety and redundancy for a couple ounces of weight. Foolish indeed.

But hey, some people are doing this single source ignition thing and haven't been bit in the ***** yet, so it's all good, right? Like I said, you won't find it in my planes because I know it cannpot be defended against when the chips go down.
A dead battery can't be defended against. A bad radio link can't be defended against....and on and on.
Our game requires some risk every time we boot it up.
Old 02-16-2011, 09:12 AM
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Default RE: Running CDI from RX

Understand, but why increase risk when it's not warranted? You folks want to play with some cheap electronic gimmickry designed and promoted by people interested only in corporate or individual profitability. OTH, I work with stuff using redundant electrical safety circuitry, the best components your money can buy, and still manage to wipe out a control system every time a spark plug cap fails to maintain ground or experience a ceramic failure on the plug body.

Hobbyiests use some of the cheapest cap designs availble while I use aircraft grade designs. Hobby ignition plug wires are about as low brow as can be, are prone to failure, yet people seem to believe they have and are using the latest in ignition technology. So the next thing they do is remove the only electrical real isolation they have from the rest of their system by running ignition off of a single or paired flight battery. You save what, 2.5 ounces overall?

It's your plane and your money, but as Pe noted, it's not just your risk. Bear that in mind if and when something happens. Your only arguement is that these devices shave a couple ounces of weight. That's a very poor reason to place everything and everyone at risk.
Old 02-16-2011, 09:22 AM
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Default RE: Running CDI from RX

the unit from tech-aero does look good. I havent seen one or used one though so cant comment.

I too just prefer to use seperate batteries, 50cc and above planes dont suffer from an extra4 cell pack weighton the ignition anyways. Maybe smaller planes could benefit from it doing away with seperate batteries, but at what risk? I do use opto kill switches though. wouldnt fire up a 50cc plane without one.

we also used to fly large planes on Nicads, wouldnt do that anymore ................so the time will come where maybe we can use only a single battery
Old 02-16-2011, 10:35 AM
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Default RE: Running CDI from RX


ORIGINAL: Tired Old Man


It's your plane and your money, but as Pe noted, it's not just your risk. Bear that in mind if and when something happens. Your only arguement is that these devices shave a couple ounces of weight. That's a very poor reason to place everything and everyone at risk.
Nope...Wrong on that one. Safety is actually enhanced, on the ground especially. I've seen guys put their hands through props trying to get to a switch.

The overall risk is probably no worse or better though. An extra bat and switch have the same number of connections as the IBEC adds. Can the IBEC die? Sure...so can the battery or switch. The result is no different, one compared to the other...engine dies. One small difference, the Tech Aero IBEC actually tells you when it's dead or not armed
Old 02-16-2011, 10:36 AM
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Default RE: Running CDI from RX

It certainly would be nice. As things stand those seriously weight conscious could fly at lighter weights using a 2s 800 ma lipoly with a diode to drop voltage to 5v. If they are still afraid of their itty bity gassers they could go back to glow where they had none of the multiple safety redundancies they insist on with gas.

Sorry, all of this has taken me back to the anal attitudes some people develop the moment they put a gas engine on something. For some reason they don't have the same safety concerns with a glow engine swinging a meat cleaver of any size. Fuel cut off at the throttle trim seems to be just fine with those. They can install and set up radios just fine in those but they become mindless and forget everything when they set up a radio in a gas powered plane.
Old 02-16-2011, 12:31 PM
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Default RE: Running CDI from RX

I fly helicopters, so I see no reason to be so anal. You want something to be anal about, hover a 700 at 1900rpm 20 feet from you.
In addition, don't bash a product unless you have personal experience with it.
Old 02-16-2011, 01:30 PM
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Default RE: Running CDI from RX


ORIGINAL: MTK


ORIGINAL: Tired Old Man


It's your plane and your money, but as Pe noted, it's not just your risk. Bear that in mind if and when something happens. Your only arguement is that these devices shave a couple ounces of weight. That's a very poor reason to place everything and everyone at risk.
Nope...Wrong on that one. Safety is actually enhanced, on the ground especially. I've seen guys put their hands through props trying to get to a switch.

The overall risk is probably no worse or better though. An extra bat and switch have the same number of connections as the IBEC adds. Can the IBEC die? Sure...so can the battery or switch. The result is no different, one compared to the other...engine dies. One small difference, the Tech Aero IBEC actually tells you when it's dead or not armed
I use the 42% optically-coupled kill switch. I can kill the motor from the Tx, and if the rx loses signal or battery the switch instantly kills the ignition. This makes it pretty hard to come up with a scenario that would result in a powered fly-away, and still preserves the isolation of seperate rx/ignition power sources.
Old 02-16-2011, 02:21 PM
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Default RE: Running CDI from RX

But to further my earlier point, what do people have on Moki 2.10's, OS BGX, and Supertigre 3500's? 35 to 50cc gas engine equivalents.

As to not having exprience with different products, don't go there. Because I don't use some things on my models does not mean there is no or limited experience with them.
Old 02-16-2011, 02:45 PM
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Default RE: Running CDI from RX

I do not poo-hoo anything.
Not speaking of someone else, but for automotive useI have personally been in electronics test programs. As such have personally seen in special RFItest chambers how powerful RFI sends ECU outputs down the cliff as if they were commanded by external analog controls.
If the maker of the device has certified his product to be absolutely free of unwanted responses to-, or passing white noise RFI disturbances to other devices I still would maybe consider, but still be very careful in using it. I have not seen such certification, and until I have, will not advise anyone to use it directly (galvanicly) connected to any onboard radio receiver.
ORIGINAL: MTK


ORIGINAL: pe reivers

It's your decision, but not only your risk, unless you fly alone.
The main rule in my book still is: ''better safe than sorry''
Pe reivers
Before poo-pooing the device, try it. I think you will be impressed. Ed Alt, the designer, knows more about spurious RFI getting back to the RX than practically everyone around, on par with Dean Pappas. The man designs electronic systems for the DOD.

As far as safety goes, arming-disarming and fail safe set-up of the CDI via the radio, is much safer than getting to a switch by hand on the plane. Consider what happened to me last year, where the thottle link became disconnected. I simply shut the thing down remotely rather than have to run out a tank or take a chance landing at high idle. Which is more dangerous?

I fly with a group. I don't hesitate using mine. The risk is lower with it in my view than without it. And BTW-I've been flying RC since 1969...I think I know what I'm talking about too


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