Do you have to have a PCM radio to fly a gasser?
01-28-2003, 06:50 PM
#51
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Do you have to have a PCM radio to fly a gasser?
Originally posted by leroifort
It's simply because pcm allow to program a fail safe mode in case of the bird lost the tx signal.
<snipped for brevity>
I hope I am more clear now, but this is only my humble opinion
It's simply because pcm allow to program a fail safe mode in case of the bird lost the tx signal.
<snipped for brevity>
I hope I am more clear now, but this is only my humble opinion
And I share the same opinion on PCM during events. The use of failsafe can mean a lot in regards to safety, and is probably the biggest reason I use PCM in my larger airplanes. I have the option, and full control, on whether or not my plane hits something the with engine dead, rather than at whatever a PPM receiver might be doing with it at the time, which could be full throttle. If it hits something, its bad enough when dead stick. But, with a 32" prop turning 6,500rpm, it would be a lot worse!
If its a large crowd, like at Joe Nall, Westport, etc, I also have the failsafe set to input a snap roll. The advantage to that is that a plane will not travel far with a dead engine and a snap roll input. In fact, it is almost guaranteed to stay on the right side of the flight line. If the interference stops, I can recover and land dead stick. If it doesn't, at least its far less likely to hit something on the wrong side of the flight line. And personal safety is far more important to me than what happens to my airplane.
01-29-2003, 04:17 AM
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Wow ! To PCM or PPM, that is the question?
Let me see if I have this right. The Fuju 50 I am going to use in a Pitts 1/3 scale will be using a spark ignition vs electronic, as I understand it. The Automatic timing device, ATD, should not be confused with electronic ignition, thus no ignition battery needed. I am going to use a single 1700 mah battery to power receiver and servos. 6 servos. 2 ailerons, 2 elevator, 1 rudder and 1 throttle. All 80 pound torque, metal geared, except the throttle.
Fighterpilot stands firm with the throttle servo mounted on the firewall, near the engine which is how I would prefer to mount the servo using a non-mental pushrod and non-mental clevis. I have already purchased a PCM receiver and had planned to keep the antenna inside, however this would place the antenna near three servos in the tail. Not good from what I gather. Better to go outside behind the canopy and up to the tail, well away from all metal parts.
PCM or PPM? The debate continues with strong opinions for both. I gather that a PPM receiver is more likely to detect a problem that a PCM receiver will hide, potentially biting you at anytime, but then fail-safe, if set up correctly, is more like to enable you to recover form a hit. The best argument seems to be the best of both worlds. Test with PPM to find the problems, correct them, and use PCM, with proper fail safe programming, for interference masking when it occurs. Range check with engine off and on is well understood.
As for the wiring, I gather from the comments that standard wiring will work if it is kept clear from the engine, at least 16"-18" and all other metal objects that could transmit interference.
Do you have any recommendations for shielding the receiver , such as a box to mount it in that would better protect from interference????
Please feel free to add any other suggestions. This is really helpful to this learning pilot on a first time gas project. I honestly appreciate your patience and help in reviewing my plans and in helping me to learn. Very concerned about safety and I would hate to crash because of something I just didn't understand in the transition from glow to gas. Gee, this is turning out to really be a project. Wish the magazines featured more on this subject.
Thanks kindly,
Fighterpilot stands firm with the throttle servo mounted on the firewall, near the engine which is how I would prefer to mount the servo using a non-mental pushrod and non-mental clevis. I have already purchased a PCM receiver and had planned to keep the antenna inside, however this would place the antenna near three servos in the tail. Not good from what I gather. Better to go outside behind the canopy and up to the tail, well away from all metal parts.
PCM or PPM? The debate continues with strong opinions for both. I gather that a PPM receiver is more likely to detect a problem that a PCM receiver will hide, potentially biting you at anytime, but then fail-safe, if set up correctly, is more like to enable you to recover form a hit. The best argument seems to be the best of both worlds. Test with PPM to find the problems, correct them, and use PCM, with proper fail safe programming, for interference masking when it occurs. Range check with engine off and on is well understood.
As for the wiring, I gather from the comments that standard wiring will work if it is kept clear from the engine, at least 16"-18" and all other metal objects that could transmit interference.
Do you have any recommendations for shielding the receiver , such as a box to mount it in that would better protect from interference????
Please feel free to add any other suggestions. This is really helpful to this learning pilot on a first time gas project. I honestly appreciate your patience and help in reviewing my plans and in helping me to learn. Very concerned about safety and I would hate to crash because of something I just didn't understand in the transition from glow to gas. Gee, this is turning out to really be a project. Wish the magazines featured more on this subject.
Thanks kindly,
01-29-2003, 05:03 AM
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Do you have to have a PCM radio to fly a gasser?
Spark ignition IS electronic just doesn't use a battery. Probably a dynamo like a car? Not sure. Can't get a spark without electricity from somewhere, mechanical or battery. Never shield the receiver, shield the source of the interference (the engine) Shielding the receiver is more likely to cause dead zones in your RF reception than anything else. Keep the antenna outside the aircraft for the same reason if possible. ANY metal object will cast RF "shadows" The longer it is and closer you are to it the more likely it is to occur. Your PCM failsafe settings should be set in order to put the aircraft into the ground as soon as possible. Any other settings and you're taking a chance with the lives around you. Especially if the aircraft manages somewhat level flight for some distance and you never regain signal you have NO idea where it will end up. Saftey before toys.
01-29-2003, 01:18 PM
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Do you have to have a PCM radio to fly a gasser?
shielding both the ignition and the reciever would be the thing the reciever it self shouldn't be recieving the signal the ant. should be i beleive the only reason you see them in plastic cases is cost(save a nickel where ever they can)if any one has been flying for a number of yrs.all the transmitters were in metal cases
i can't rember one company from the early 80's back to the 60's that wasn't in metal.
another thing you can do is shield the spark and the trigger i know you can buy the pre done spark plug wire but i've made my own a many a time not just model but in the vechile to keep the noise out of ham gear just get a couple feet of good coax cable
(rg 214 is the best for this purpose)after you have the 2 ft.carefuly take the black coating off and you'l see the braided shield this will slide off the center of the cable now you have a
flexable hollow piece in your hand put this over your sparkplug wire and grouind it to the motor. also in you have a electronic ignition i have found the trigger wire to produce noise (the wire coming from the pickup sensor) do the same thing like i said above with the sparkplug wire these are about the 2 worst areas
of giving you a problem.
roy
i can't rember one company from the early 80's back to the 60's that wasn't in metal.
another thing you can do is shield the spark and the trigger i know you can buy the pre done spark plug wire but i've made my own a many a time not just model but in the vechile to keep the noise out of ham gear just get a couple feet of good coax cable
(rg 214 is the best for this purpose)after you have the 2 ft.carefuly take the black coating off and you'l see the braided shield this will slide off the center of the cable now you have a
flexable hollow piece in your hand put this over your sparkplug wire and grouind it to the motor. also in you have a electronic ignition i have found the trigger wire to produce noise (the wire coming from the pickup sensor) do the same thing like i said above with the sparkplug wire these are about the 2 worst areas
of giving you a problem.
roy
01-29-2003, 04:41 PM
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Do you have to have a PCM radio to fly a gasser?
One more thing not mentioned here that I have learned from the Gas Boating community is:
If you don't test your Gas powered plane first with a PPM receiver and it is emitting a lot of noise, it could adversely affect other people's planes that fly near yours.
The Gas Boaters strongly advise everyone to test with PPM and make sure your boat is not going to be a problem for other peoples boats. You could be masking your problem with PCM and don't know it exists.
Just because you ignore the noise with PCM does not mean it is gone. I fly(and boat) PCM only, but I test with AM and FM PPM first.
I am new to Gas powered planes, flying Nitro since 86, but I firmly believe the gas boaters have had problems with this issue.
Consider yourself and others and you will both have a great day at the field!
William
If you don't test your Gas powered plane first with a PPM receiver and it is emitting a lot of noise, it could adversely affect other people's planes that fly near yours.
The Gas Boaters strongly advise everyone to test with PPM and make sure your boat is not going to be a problem for other peoples boats. You could be masking your problem with PCM and don't know it exists.
Just because you ignore the noise with PCM does not mean it is gone. I fly(and boat) PCM only, but I test with AM and FM PPM first.
I am new to Gas powered planes, flying Nitro since 86, but I firmly believe the gas boaters have had problems with this issue.
Consider yourself and others and you will both have a great day at the field!
William
01-29-2003, 06:39 PM
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Do you have to have a PCM radio to fly a gasser?
Speaking of noise, PCM, and the mention of failsafe earlier, I thought I would mention this.
As mentioned in my earlier post, I usually setup all my PCM airplanes to failsafe with the throttle to kill. Depending on where I am flying, I would either set the rest of the channels to either hold or a snap roll input for safety reasons.
Well, I was in the shop a little while ago setting up the smoke pump for my Decathlon. And I remembered another advantage for the failsafes. On all my airplanes, I had the failsafe set to turn off the smoke pump, the ignition if I am using a ignition kill switch, and any other extraneous equipment on board. My reasoning is if the source of the interference is the smoke pump, ignition, etc, turning it off could kill the source of the problem. I'd probably get control back, and have it jump back into failsafe again. But, it has alerted me to that one of those channels is the source of the problem, and I can turn them all off on the transmitter.
Would I be sharp enough to figure it out right away and save the plane. Maybe not. But if I am high enough, there is a good possibility. Its worth setting it up this way in any event.
Just thought I would mention it.
As mentioned in my earlier post, I usually setup all my PCM airplanes to failsafe with the throttle to kill. Depending on where I am flying, I would either set the rest of the channels to either hold or a snap roll input for safety reasons.
Well, I was in the shop a little while ago setting up the smoke pump for my Decathlon. And I remembered another advantage for the failsafes. On all my airplanes, I had the failsafe set to turn off the smoke pump, the ignition if I am using a ignition kill switch, and any other extraneous equipment on board. My reasoning is if the source of the interference is the smoke pump, ignition, etc, turning it off could kill the source of the problem. I'd probably get control back, and have it jump back into failsafe again. But, it has alerted me to that one of those channels is the source of the problem, and I can turn them all off on the transmitter.
Would I be sharp enough to figure it out right away and save the plane. Maybe not. But if I am high enough, there is a good possibility. Its worth setting it up this way in any event.
Just thought I would mention it.
01-29-2003, 06:43 PM
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Do you have to have a PCM radio to fly a gasser?
Originally posted by sfaust
Speaking of noise, PCM, and the mention of failsafe earlier, I thought I would mention this.
As mentioned in my earlier post, I usually setup all my PCM airplanes to failsafe with the throttle to kill. Depending on where I am flying, I would either set the rest of the channels to either hold or a snap roll input for safety reasons.
Well, I was in the shop a little while ago setting up the smoke pump for my Decathlon. And I remembered another advantage for the failsafes. On all my airplanes, I had the failsafe set to turn off the smoke pump, the ignition if I am using a ignition kill switch, and any other extraneous equipment on board. My reasoning is if the source of the interference is the smoke pump, ignition, etc, turning it off could kill the source of the problem. I'd probably get control back, and have it jump back into failsafe again. But, it has alerted me to that one of those channels is the source of the problem, and I can turn them all off on the transmitter.
Would I be sharp enough to figure it out right away and save the plane. Maybe not. But if I am high enough, there is a good possibility. Its worth setting it up this way in any event.
Just thought I would mention it.
Speaking of noise, PCM, and the mention of failsafe earlier, I thought I would mention this.
As mentioned in my earlier post, I usually setup all my PCM airplanes to failsafe with the throttle to kill. Depending on where I am flying, I would either set the rest of the channels to either hold or a snap roll input for safety reasons.
Well, I was in the shop a little while ago setting up the smoke pump for my Decathlon. And I remembered another advantage for the failsafes. On all my airplanes, I had the failsafe set to turn off the smoke pump, the ignition if I am using a ignition kill switch, and any other extraneous equipment on board. My reasoning is if the source of the interference is the smoke pump, ignition, etc, turning it off could kill the source of the problem. I'd probably get control back, and have it jump back into failsafe again. But, it has alerted me to that one of those channels is the source of the problem, and I can turn them all off on the transmitter.
Would I be sharp enough to figure it out right away and save the plane. Maybe not. But if I am high enough, there is a good possibility. Its worth setting it up this way in any event.
Just thought I would mention it.
01-29-2003, 06:48 PM
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Do you have to have a PCM radio to fly a gasser?
I only kill the engine for safety reasons, otherwise I would also just go to idle. Unless I am doing a torque roll, or flying inverted on the deck, killing the engine is nothing more than a dead stick landing. Should be uneventful. I've had lots of practice from flying glow engines
01-30-2003, 03:46 AM
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IGNITION INSTALLATION
HELP, I JUST INSTALLED A ZDZ 80, i PLACE THE THROTTLE SERVO
5 " FROM ENGINE INSIDE ENGINE BOX.
i THEN INSTALLED THE IGNITION MODULE ON OUTSIDE WALL
OF BOX. (3/4 ") BETWEEN IT AND THE SERVO.
REALLY NEAT AND NICE LOOKING JOB. WAS BY CHANCE LOOKING OVER SOME STRAY PAPERWORK ON THE ZDZ, AND IT STATES
(MOUNT IGNITION MODULE, ENGINE WIRES, ENGINE AT LEAST 25
CM CENTAMETERS AWAY FROM ALL RADIO ,SERVO, WIRES AND COMPONANTS.
HECK, THATS OVER 10 INCHES. ON AN EDGE 30% THE ONLY PLACE TO MOUNT A SWITCH IS IN FRONT OF THE WING.
THE OTHER SIDE OF PLANE SAME AREA IS WHERE I MOUNTED THE ENGINE SWITCH.
CAN SOMEONE TELL ME HOW CRITICAL IT IS TO MAINTAIN 25 CM
CLERANCE ??????? AND HOW TO GO ABOUT IT>???
5 " FROM ENGINE INSIDE ENGINE BOX.
i THEN INSTALLED THE IGNITION MODULE ON OUTSIDE WALL
OF BOX. (3/4 ") BETWEEN IT AND THE SERVO.
REALLY NEAT AND NICE LOOKING JOB. WAS BY CHANCE LOOKING OVER SOME STRAY PAPERWORK ON THE ZDZ, AND IT STATES
(MOUNT IGNITION MODULE, ENGINE WIRES, ENGINE AT LEAST 25
CM CENTAMETERS AWAY FROM ALL RADIO ,SERVO, WIRES AND COMPONANTS.
HECK, THATS OVER 10 INCHES. ON AN EDGE 30% THE ONLY PLACE TO MOUNT A SWITCH IS IN FRONT OF THE WING.
THE OTHER SIDE OF PLANE SAME AREA IS WHERE I MOUNTED THE ENGINE SWITCH.
CAN SOMEONE TELL ME HOW CRITICAL IT IS TO MAINTAIN 25 CM
CLERANCE ??????? AND HOW TO GO ABOUT IT>???
01-30-2003, 03:54 AM
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Re: IGNITION INSTALLATION
Originally posted by HAWKMAN103
HELP, I JUST INSTALLED A ZDZ 80, i PLACE THE THROTTLE SERVO
5 " FROM ENGINE INSIDE ENGINE BOX.
i THEN INSTALLED THE IGNITION MODULE ON OUTSIDE WALL
OF BOX. (3/4 ") BETWEEN IT AND THE SERVO.
REALLY NEAT AND NICE LOOKING JOB. WAS BY CHANCE LOOKING OVER SOME STRAY PAPERWORK ON THE ZDZ, AND IT STATES
(MOUNT IGNITION MODULE, ENGINE WIRES, ENGINE AT LEAST 25
CM CENTAMETERS AWAY FROM ALL RADIO ,SERVO, WIRES AND COMPONANTS.
HECK, THATS OVER 10 INCHES. ON AN EDGE 30% THE ONLY PLACE TO MOUNT A SWITCH IS IN FRONT OF THE WING.
THE OTHER SIDE OF PLANE SAME AREA IS WHERE I MOUNTED THE ENGINE SWITCH.
CAN SOMEONE TELL ME HOW CRITICAL IT IS TO MAINTAIN 25 CM
CLERANCE ??????? AND HOW TO GO ABOUT IT>???
HELP, I JUST INSTALLED A ZDZ 80, i PLACE THE THROTTLE SERVO
5 " FROM ENGINE INSIDE ENGINE BOX.
i THEN INSTALLED THE IGNITION MODULE ON OUTSIDE WALL
OF BOX. (3/4 ") BETWEEN IT AND THE SERVO.
REALLY NEAT AND NICE LOOKING JOB. WAS BY CHANCE LOOKING OVER SOME STRAY PAPERWORK ON THE ZDZ, AND IT STATES
(MOUNT IGNITION MODULE, ENGINE WIRES, ENGINE AT LEAST 25
CM CENTAMETERS AWAY FROM ALL RADIO ,SERVO, WIRES AND COMPONANTS.
HECK, THATS OVER 10 INCHES. ON AN EDGE 30% THE ONLY PLACE TO MOUNT A SWITCH IS IN FRONT OF THE WING.
THE OTHER SIDE OF PLANE SAME AREA IS WHERE I MOUNTED THE ENGINE SWITCH.
CAN SOMEONE TELL ME HOW CRITICAL IT IS TO MAINTAIN 25 CM
CLERANCE ??????? AND HOW TO GO ABOUT IT>???
Firewall Forward
10-31-2003, 11:35 AM
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RE: Re: IGNITION INSTALLATION
hi,
i have a question I use a t9cap with pcm reciever how far do a need to walk for a range check i walked about 60mtr.
as i moved my sticks (elevator) i found that one rudder would stay behind as if the signal would not come through could any of you explain it to my if this is normal thanks..
i have a question I use a t9cap with pcm reciever how far do a need to walk for a range check i walked about 60mtr.
as i moved my sticks (elevator) i found that one rudder would stay behind as if the signal would not come through could any of you explain it to my if this is normal thanks..
10-31-2003, 08:57 PM
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RE: Re: IGNITION INSTALLATION
hmm all i have to add...is:
i fly choppers as well.... nothing special....i run the ppm recievers in the .30 sized plastic birds. and tried for a long while to run ppm in my metal .60 sized bird...(against all warnings)... was unsafe to put it mildly...no way it was going to work...i tried allot of things mentioned in previos posts on this thread.. and even got glitch`s/problems to go away for periods of time..but they ALWAYS returned at the most unexpected times..
so i went to pcm on my metal birds....and never..(i will say never) had a problem with a radio glitch issue since then in 7+ years.. on my big birds..(metal ones)
just to much Noise in my opinion... could be a HUGE variety of things... from a servo,,,, to a bearing...on a pivot.. anything...
and running a pcm may "cover up or mask" issue...but it cures all symptoms..(maybe not problem) but. ...i have enjoyed flying since...with out having to get degree in electronics.
in a nutshell... if ppm causes issue`s get a pcm reciever.... just over a $100 bucks.. well worth the piece of mind..
i still run ppm in my inexpensive stuff......and i put pcm in my stuff i am concerned with.
and i too have had some planes for "years"
i fly choppers as well.... nothing special....i run the ppm recievers in the .30 sized plastic birds. and tried for a long while to run ppm in my metal .60 sized bird...(against all warnings)... was unsafe to put it mildly...no way it was going to work...i tried allot of things mentioned in previos posts on this thread.. and even got glitch`s/problems to go away for periods of time..but they ALWAYS returned at the most unexpected times..
so i went to pcm on my metal birds....and never..(i will say never) had a problem with a radio glitch issue since then in 7+ years.. on my big birds..(metal ones)
just to much Noise in my opinion... could be a HUGE variety of things... from a servo,,,, to a bearing...on a pivot.. anything...
and running a pcm may "cover up or mask" issue...but it cures all symptoms..(maybe not problem) but. ...i have enjoyed flying since...with out having to get degree in electronics.
in a nutshell... if ppm causes issue`s get a pcm reciever.... just over a $100 bucks.. well worth the piece of mind..
i still run ppm in my inexpensive stuff......and i put pcm in my stuff i am concerned with.
and i too have had some planes for "years"
10-31-2003, 09:24 PM
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RE: Re: IGNITION INSTALLATION
I will add my 2 cents:
I only use PCM , never had a radio problem and I fly in micro wave hell about 6miles from NYC.
My thought is why take a chance. PJAMESRC
I only use PCM , never had a radio problem and I fly in micro wave hell about 6miles from NYC.
My thought is why take a chance. PJAMESRC
11-02-2003, 03:35 PM
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RE: Do you have to have a PCM radio to fly a gasser?
I was at an IMAA meet in Lyman Wa. about two years ago.
A fellow with a Balsa USA 1/3 scale Sopwith Pup said that due to all of the flying wires creating noise he could not get it to range check with a PPM receiver (with the engine running) so he had put in a PCM receiver and everything was fine.
I bit my tounge and did not say anything.
The next day he let it go low and far out. It went into hold PCM hold and since he had not bothered to program the fail safe it crashed with full throttle. The airplane was completly destroyed
A fellow with a Balsa USA 1/3 scale Sopwith Pup said that due to all of the flying wires creating noise he could not get it to range check with a PPM receiver (with the engine running) so he had put in a PCM receiver and everything was fine.
I bit my tounge and did not say anything.
The next day he let it go low and far out. It went into hold PCM hold and since he had not bothered to program the fail safe it crashed with full throttle. The airplane was completly destroyed
