DrDeath

My Feedback: (3)

I know that I maybe opening a BIG can of worms. I also know that I will probably get a lot of different opinions. I am running a JR 8103 and all of my planes currently FM rx. I have a couple of questions:

1) Concern about LOCK-OUT, what are the pros and cons?
2) Which is really better (loaded question)?
3) S-PCM vs Z-PCM which is better?

All answers with technical information to back up opinion will greatly be appreciated. Thanks in advance.

howardm4

My Feedback: (1)

a quick google search of the two words 'PCM failsafe' will get you more unbiased
information than you can use.

Let's be clear right off the bat. NOTHING
is more important than preventing
bodily harm to other people w/ your model.
Everything else is ultimately secondary.

So, assuming that you have lost radio
contact w/ the model, do you prefer to
have a completely out of control machine
that is doing anything it wants or do
you prefer a machine that you can
tell 'shut the engine down, setup
control surfaces to a predetermined
position and hope for the best'

SMALLFLY-

My Feedback: (19)

I would refer you to page 58 RC report May 2003. Do a search this topic has come up many times before

JohnW

My Feedback: (6)

This was pretty much beat to death a few months ago... I doubt anyone's opinion has changed much since then. I agree with what howardm4 posted. Ultimately, PCM properly setup can and will help prevent property damage and personal injury.

The concern most have about failsafes (lockout) is they don't like the idea of having no control over the aircraft. The thing is, the reason PCM goes into failsafe in the first place is because you have no control over the aircraft. As soon as a good signal is received, PCM failsafes release and control is returned to the pilot.

S & Z are a JR thing. I don't run JR but I know one is 512PCM and the other is 1024PCM. I don't know which is which, but the 1024PCM would be better since it offers twice the precision of the 512PCM standard.

Cheers

sfaust

My Feedback: (11)

The above pretty much matches my view as well. I've bench tested the ability of the pilot to control the servos during an interference event. I interjected random interference then tried to see what control I had over the servos. I had nada. I held full left aileron and rudder, and full up elevator. All the surfaces moved in whatever direction they had. There wasn't even a slight bias towards the inputs I was putting in.

I also think many are afraid of PCM because they feel that once the model goes into lockout, it never comes back. If that was the case, it would be worse than using standard PPM. However, once the interference stops, control IS returned to the pilot within 50milliseconds. Thats damn fast in anyones book. Now if only my servos were that fast!

Tiger

My Feedback: (7)

Nooooo!!!!! Not again!!!!!!!!

JohnVH

My Feedback: (38)

you want SPCM, that is the better of the two.

DrDeath

My Feedback: (3)

Thanks. I am reading up on PCM to fully understand it before I make the $$$ investment in new receivers for my 1/4 scale planes. I have only joined this forum about 2 1/2 months ago, but after reading other debates, I figured that this was a hot topic. Thanks for the input.

Lee

FLYBOY

My Feedback: (11)

It is a pretty touchy subject for some. While some feel very strongly for PCM, others hate it. I personally use them both. I do know that if my float plane wouldn't have had a PCM rec in it, I wouldn't have it any more. A guy turned on his radio on the same freq to start his plane. I didn't even notice. No change in flight, he was glitching like crazy. I asked what freq he was on and he said, opps, same as you. I like the safety of PCM personally. They still get hit, but I don't think you can stop 100% of the hits. I know my FM would have tucked and rolled in the same situation.

Forgues Research

My Feedback: (7)

If you want failsafe, you don't need to go with PCM, you can go with PPM IPD's from Multiplex.

elmote

There is quite the lively and animated discussion of PPM/PCM on "another forum" right now. I posted a question and was ignored (probably due to being a newbie). Anyone here have an opinon on my question?......

If F/S was set to move collective to hover throttle/pitch or slightly below, cyclic centered, would the Copilot just put it into hover, since it's not receiving an overriding signal from the TX?

Elmo Te

Lynx

It should.