Radio control

[rwheller]

I am looking for a reliable, long range, remote control system for running an electric locomotive in 1.6" scale. I do a lot of yard switching and want to eliminate the tethered control box. I tried Futaba but the range was less than acceptable. I can use anything that uses either PWM for speed control or standard R/C servo outputs.

[hammermill]

i cant recomend a brand but those of us with ham lisences could use other frequencys and higher power levels
with various rc controllers. as a example a dtmf (touch tone controler) can give 18 commands that could be broken out to seperate commands


here is somethingin the comerical range

http://kpr.craigslist.org/tls/3569457769.html far differient idea

[Steve C]

What distance do you need the radio to work at? I have used Futaba and Airtronics radios years ago and had a range of over 100 yards in an open area. have you tried talking to a local hobby shop about the range of various radios, the radios for aircraft may have a longer range.

Steve

[Steve C]

Did a quick internet search and found this article on radios and their ranges,
http://www.bigsquidrc.com/2-4-ghz-radio ... dio-range/ There are 2 radios that went over 1000' 2 more that did over 800'.

Steve

[hottshot65]

I find a lot of guys get their jollies off by being able to run their locomotive two miles away. That kind of mentality is the exact opposite we need in this hobby. The emphasis should be on fail safes. That is the controls should drop to zero once they reach a certain distance from a locomotive, say 50 to 100 feet. It's not worth the risk of having a 1000 lb runaway locomotive. Safety needs to be put ahead of ego.

[Bill Wilkins]

As far as the RC radios are concerned you would have to use a "surface" frequency. "Air" frequencies are different. Or use the 2.4 ghz freqs.
Check here for proper "surface" frequencies available. http://www.modelaircraft.org/
I think your barking up the wrong tree personally.
Bill W.

[WJH]

The higher end 2.4ghz radios will do over 1 mile in an airplane. As far as on the ground expect much less but still more than you could want for this. The older fm radios that were high end like my Jr 8103 used pcm where the servos would go to a pre programmed position in case of a lost radio signal. That would be ideal for this application. Stay away from cheap Hong Kong radio junk. Stick with high end Futaba, JR, or Spectrum. Sounds like you were using a cheap old school Futaba car radio on the 49mhz am band or a new cheap 2.4ghz freebie radio they throw into RTR packages.

[one_inch_railroad]

A good radio and receiver would be the Futaba 6EX 2.4 GHz 6 channel radio. For those unfamiliar with how the 2.4 GHz radio systems work compared to the standard FM transmitters and receivers of the past here is a site that describes the differences. Basically the specific transmitter and receiver you buy are linked together so that no other radio, even the same model from the same manufacturer will be able to communicate with your receiver.

http://www.rcmodelreviews.com/spreadspectrum01.shtml

I will be using a 4QD motor controller for my interurban with the 4QD radio control interface board. The interface board also has a fail-safe that compares the validity of incoming signals. Each pulse is tested to determine whether it is likely
to be a valid pulse, or just a section of random receiver output. zero when both sticks are centred, but has virtually
no effect on control.

Standard Receiver Output the standard servo-drive in Radio Control
applications is a 20 Hz PWM signal with a mark of 1.5mS at centre (zero position). When the stick is displaced from one extreme to the other, this mark changes from about 1.0mS to about 2.0mS. The DMR-203 will reject signals that differ
sufficiently from this standard. When the signal quality is below an acceptable standard, DMR-203 enters failsafe mode, and all outputs are set to safe values. The failsafe algorithm used by the DMR-203 is simple and yet effective.
Each pulse is tested to determine whether it is likely to be a valid pulse, or just a section of random
receiver output. The results of this test are used to define whether the input signals can be trusted. If not, the DMR-203
goes into failsafe mode, and the outputs are set to zero. A valid pulse must have a mark of between 0.8 and 1.2 ms, and must be followed by a space of at least 13 ms. All pulses that do not conform to this standard are treated as invalid.
The unit will enter failsafe mode if, over any period defined by FT , no sequence of 4 consecutive valid pulses occurs. This works well because it is very unlikely that a random signal will contain a section that looks like 4 consecutive valid pulses. The system looks at both channels at the same time, so a set of 4 consecutive pulses could consist of 2 pulses from each channel received alternately (if pulses arrive simultaneously on both channels,
channel one is treated as if it arrived first), or if only one input is connected, 4 pulses from that input. When an invalid pulse is received, the output will correspond to the last valid input, unless, or until, the failsafe has activated.

The Futaba 6EX also has a programmable failsafe mode that is user programmable when the receiver loses contact with the transmitter. So for instance when flying an airplane it could be used to reduce the throttle to cruising setting and return all control surfaces for level flying. On something like a 1.6 ride on locomotive the throttle output could be set to return to zero output.

Here is a link for the 6EX that has reviews and the manual for the 6EX as well.

http://www3.towerhobbies.com/cgi-bin/wt ... LXPZT8&P=3

[Bill Shields]

i am with the 'runaway radio control' group - and do not want to see it at the steam track.

While I know of many good radio / receiver / failsafe options, I would rather not recommend, other than to say that if the radio does not have a fail-safe that will slam the throttle shut if the connection is lost, then its use should not even be considered or allowed at a track.

[bcody]

AMEN


Bill

[amadlinger]

Hi all,

I, too, wholeheartedly agree that a fail safe is required. But before you give Mr. Heller too much grief, I would just like to say that I am 100% confident that he has already thoroughly considered and implemented such a fail safe in his present system and will do so on the next as well. I wouldn't put it past him to design and build a fail safe system himself, redundant to internal R/C unit's fail safe, just in case!

By way of background, since Ron is far too modest to brag about his abilities and accomplishments himself, I should mention that he is an electronics guru if there ever was one, and has been known to include every bell and whistle imaginable in his electronic systems (literally!). If anyone can do it safely, he can.

I know one of the biggest headaches he has been working to overcome with R/C control is the issue of RF interference at the Pennsylvania Live Steamers, which is located immediately adjacent to high tension wires and a small electric substation. Come to think of it, Waushakum Live Steamers also has high tension wires. Ron, have you had difficulties there as well?

Sincerely,
Adam

[amadlinger]

Ron,

Sorry, a follow-up question: I know you are using the 4QD-200 controller, does that mean you are using 4QD's DMR-203 Series Dual-Channel Radio Control Interface as well?

http://www.4qd.co.uk/accs/dmr3.html

It sounds like you are, because (as I understand it) the DMR-203 gives you the ability to convert pretty much anybody's R/C system into the input for the PWM card. And I also note that the DMR-203 has a built-in fail safe...

Sincerely,
Adam