BBriBro

My Feedback: (2)

3 of us are having trouble solving glitching problems. I have never used a PCM receiver, even with ignition engines. A G-23, Q-75, G-62 and a Brison 3.2 One friend says that you can use PPM with a magneto, but the electronic ignitions require PCM, Now I have disproved that with the Brison, and another friend has G-62 and Q-75 both with electronic ignition, and they work fine. The problem seems to be with the ZDZ 80 and one with a RCS 140. Two diff people, same engine (zdz 80) , Both use Futaba radio gear, one is a Super 8 and one is a 9 Cap TX with Futaba receivers. They have the same prob, and now I am concerned because my new project has a ZDZ 40. What are the "rules of thumb" concerning PCM, I have heard helis need them because of the vibration, I have heard ducted fans need them because of the high rpms cause a high frequency vibration, And the debate of electronic ignition vs magneto. My Brison has a rubber spark plug boot and high tension lead, not the metal cap and braided wire many recommend, but yet it works fine. The one with the RCS 140 is the worst, all channels go nuts at 50 ft with the antenna colapsed, the ZDZ 80 is a little better ( he flew it) but you could hear the throttle blipping in the air and see the rudder twitching, so he landed before he lost his new 1/3 scale laser. They both ordered PCM receivers that day, But I would like to know why we are having trouble all of a sudden after years of flying similar equipment. At 1st I thought the ignition ZDZ uses was to blame, (are there any known issues about this?) but the RCS does it to, and I think it uses a different ignition system. Any ideas?

Mike Bell

My Feedback: (6)

I would like to see an answer on this.
I have a ZDZ 80 and get a glitch using PPM sometimes.
Think PCM may be the ticket

Phil Cole

There was a long thread on this subject a week or two ago. All of the relevant issues were discussed.

sfaust

My Feedback: (11)

Phil's got it right. Take a few minutes to search and find the posts. Its all covered very well from all points of view.

There are hundreds?, thousands?, of planes out there running PPM with gas engine, both magneto and electronic ignition. PCM is not required, and in fact, if you don't understand how PCM works, its ability to mask interference, and how to work around it, its wise to stay with PPM. PCM has benefits, but some significant watch outs as well.

The last thing you want to do is put a in PCM receiver in order to solve a glitching problem. Solve the problem first, which can be done with a little elbow grease, then go to PCM if thats what you want, and if you fully understand how it all works (masking, hold, failsafe (or lockout).

Its worth the time to do the search.

wgeffon

My Feedback: (4)

Thank you Stephen.
Now I dont have to type that!

( How about everyone gives me a dollar anytime this subject gets brought up..... )

sfaust

My Feedback: (11)

How about $4 every time I type it Its more work to type it!

BBriBro

My Feedback: (2)

How about everyone gives me a dollar when someone says "use search" ? I read many pages on the topic, Maybe you could provide a link to the discussion you are referrung to, Searching for PCM is too vague, PCM vs PPM didn't produce too much. Thats just the way forums are, and besides, I didn't see anything that specifically talked about the ZDZ engine and Falkon ignition, just gas engines in general, I was wondering if the Falkon acts differently than the typical CH ignition or some other "garden variety"

sfaust

My Feedback: (11)

Here are some search links....

http://www.rcuniverse.com/showthread...hlight=pcm+ppm

http://www.rcuniverse.com/showthread...hlight=pcm+ppm

http://www.rcuniverse.com/showthread...hlight=pcm+ppm

http://www.rcuniverse.com/showthread...hlight=pcm+ppm]

BBriBro

My Feedback: (2)

Thanks, I never thought to search for things like "gasser" I try to be precise and technically correct. Searching for just PCM produced 28 PAGES of threads, I am not even half way through all those..

sfaust

My Feedback: (11)

I actually cheated. Since I knew I was involved in a couple of those discussions, I added my name to the search. There are probably many other good threads that I didn't post anything on, so look further than the links I posted above. Those should be a good start though, and they do cover the subject quite well.

xp8103

My Feedback: (16)

Stephen's right. PCM doesn't SOLVE glitching problems, it only masks them. Kind of like taking NYQUIL (something I am familair with right now), it doesn't cure the cold, only masks the symptoms. For the record, my ZDZ40 with Falkon ignition did not cause any glitching in it's first run up in the plane. JR PCM Rx.

Don Panek

I have both the ZDZ 80 and RCS 140 engines. And I had problems with both after running them about 20 minutes. At full throttle they began missing and causing servos to glich. I contacted Dooley at RCS and he knew right away what the problem was,loose spark plug cap! I was told to use a hose clamp around the spark plug cap to secure it to the base of the plug. It worked for about 30 minutes running time and the problem began again. I contacted Desert Aircraft and purchased their replacemrnt cap which is easy to install and after that I have not had a single problem. Cost of the cap was $22.00 a good investment.