# Fail-Safe Operation for Battery Power



## Del Tapparo (Jan 4, 2008)

I didn't want to hi-jack another thread, so I am bringing it here.

Posted By Michael Glavin on 04/07/2009 5:03 PM

RC with a programmable fail-safe has been around for twenty years or better with RC aircraft. The tried and true systems were digital PCM (pulse code modulation) variety and later IPD (intelligent pulse) on inteligent PPM hierarchy. Failsafe is triggered after a given time-out for lack of RF signal and or multiple corrupt data packets are decoded consecutively. The user is able to program how the RX is to react to failsafe, i.e., throttle down; turn left, a little up elevator trim or whatever as soon as GOOD data is received the link is reestablished. RC Train systems with fail safe should be easy, it only has to be applied to our hobby IMO…





Yes, that could easily be done. However,in my R/C system, as with others, I chose to let the train keep running at the present speed on loss of signal. This is especially beneficial for continuous running. The train can run for hours with the transmitter turned off, saving the transmitter batteries. There is no need for constant communication; only when you want to change something. Compared to aircraft, the chance of damage due to loss of radio control is extremely low. Damage will only occur due to multiple faults; i.e. loss of control plus poor track conditions, or an obstacle, etc. (Of course Murphey's Law does seem to apply to trains







)

So, I am curious .... Are there others out there that would like a programmable fail-safe option?


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## Cougar Rock Rail (Jan 2, 2008)

The new Massoth DRC300 r/c unit is programmable for fail safe operation to either 1) stop immediately, 2) run for a fixed time, to say clear tunnel etc, or 3) continue until reception is returned.It can run on either battery, analog track, or DCC as required using the Navigator to control it.  Since it is essentially a miniature central station, it can run any NMRA decoder, sound or otherwise with all the functionality.  So there are companies that do their homework and engineering...but once again you get what you pay for.


Keith


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## Michael Glavin (Jan 2, 2009)

Del, 

I like "fail safe" programmable features, they have there place IMO. Can you imagine a runaway consist of heavy metal with onboard controls, it could be devastating!!! But then again emergency stop switches would be plausible too. When I build my new empire I envision track power district interruption from multiple “E” stop switches located throughout the RR. Purposes built “E” switches are inexpensive and typically used on CNC equipment and such, I purchased several for my CNC projects they have big RED mushroom shaped slam-em down buttons go figure! 

Keith, 

Is the Massoth unit cable of one or the other fail-safes or multiple contingencies or channels/operations like RC aircraft? 

Michael


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## Del Tapparo (Jan 4, 2008)

Posted By Michael Glavin on 04/07/2009 6:17 PM
Del, 

I like "fail safe" programmable features, they have there place IMO. Can you imagine a runaway consist of heavy metal with onboard controls, it could be devastating!!! But then again emergency stop switches would be plausible too. 

Del's Response starts here ... (can't seem to edit it the way I want). 

Well, the intent of the thread (perhaps not stated properly) is would you like or use a programmable failsafe feature. The failure is loss of communication in a radio control system. And the question is "What would you like to have happen when that occurs, and would you like to have control over that function?" Nothing to do with on-board controls.


The options that Massoth uses are probably the only reasonable choices of action to be taken. How would you program your unit given these choices?


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## acmartina (Jan 6, 2008)

Del,
AirWire has such a feature. CV 11 is a "loss of signal timer" that allows you to set the number of seconds after loss of signal from the TX before the locomotive shuts off. Handy if your TX works well but annoying if you have range problems!
Steve


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## Michael Glavin (Jan 2, 2009)

Del, 

My reference to “on-board controls” was aimed at the ability of the on-board components (decoder) to run the loco/train anonymously when the radio link is gone… That said we are still the superior intelligence with DCC and know matter what we can choose turn off the track power, battery power is another conundrum with a higher potential for deflating ego’s. 

I would like and use programmable fail-safes if available. 

Only control we could have would be pre-determined when the radio link is broken and completely under control of the fail-safes programmed parameters via the onboard motor controller/decoder… 

A single function would likely suffice, but multiple parameters such as audible alerts, flashing lights, power down, throttle hold, timed interval op’s come to mind. 

With regard to Massoth, if a single function is it, I suppose the actual train operation and or conditions with regard to multiple trains and such might influence my choice. I would likely opt for the train to slow down and stop until a link is re-established. 

Michael


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## Paul Norton (Jan 8, 2008)

Hi Del!

I can answer a few questions about this on the new TE system.

The call for a fail safe system for the new TE has been heard, along with many other suggestions by the beta testers. Apparently it is possible and it will be looked at.

One of the alpha testers has confirmed he obtained 400 feet of range, so outrunning the radio range is not going to be a problem for most operators. The weather is still wet and snowy here, so I haven’t been able to do a range test myself.

The receiver and transmitter constantly exchange information. On the top left hand corner of the operating screen is a signal strength indicator. If the bars slowly start to disappear, you are approaching the edge of the radio range envelope.

There is also a LINK OK indicator on the bottom of the screen. If the locomotive reaches the edge of the envelope the NO LINK indicator will appear. Yes I know, a little to late for someone not paying attention unless the locomotives on a curve or the engineer is fast on their feet.

This same NO LINK indicator would appear if a track powered locomotive derailed and lost power.

On the bottom right hand corner of the operating screen is a voltage reading and graphic display of the transmitter batteries strength.


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## Michael Glavin (Jan 2, 2009)

Posted By acmartina on 04/07/2009 7:50 PM

AirWire has such a feature. CV 11 is a "loss of signal timer" that allows you to set the number of seconds after loss of signal from the TX before the locomotive shuts off. Handy if your TX works well but annoying if you have range problems!




This sounds familiar, when the radio link is broken the AireWire RX/Decoder is intelligent and realizes same and propagates a fail-safe event or mode. This is entirely done onboard the loco; no outside influence is in play until such time a radio link is reestablished.

Michael


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## Greg Elmassian (Jan 3, 2008)

Actually CV11 is pretty much a standard DCC setting, not unique to airwire.... 

Regards, Greg


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## Michael Glavin (Jan 2, 2009)

Greg, 

I was just getting ready to read up on the abilty of straight DCC decoders and CV11 functions. 

Michael


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## Paul Norton (Jan 8, 2008)

Del, as there is not an end quote indicator; using a person’s quote can be somewhat tricky, especially if you only want part of that person’s post.

I click on the persons quote and push Ctl+End. That takes me to the end of their post. I can then copy in my own information. I compose; edit and spell check mine in an Outlook message before copying it into a post.

I can then go back and remove any of the information from their post/quote that is not relevant.


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## Del Tapparo (Jan 4, 2008)

Posted By Michael Glavin on 04/07/2009 8:31 PM
Del, 

My reference to “on-board controls” was aimed at the ability of the on-board components (decoder) to run the loco/train anonymously when the radio link is gone… That said we are still the superior intelligence with DCC and know matter what we can choose turn off the track power, battery power is another conundrum with a higher potential for deflating ego’s. 




Thank you for your comments, but I really have no idea what this means.


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## Michael Glavin (Jan 2, 2009)

Del, 

If the radio link is lost, the on-board goodies have the ability to command speed, direction, lighting and more whom is in control of the train? With track power we are, with battery power you gotta move fast. That said I now understand CV11 can circumvent an episode if properly programmed. It’s all good! 

Michael


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## Del Tapparo (Jan 4, 2008)

Michael - I am having a hard time understanding your concern over battery power. But it sounds like you are assuming that due to loss of radio control, the train is now speeding down the track at run-away speeds and something must be done right now to avoid disaster. I suppose that is certainly possible, but it is a worst-case scenario. It probably depends on your layout. 

The way it works on my layout, and I am assuming many more, is my train is capable of continuous running unattended (no speed changes required). So upon loss of radio signal, the vast majority of the time it can take care of itself. So my controls are programmed to continue running at the present speed on loss of signal (as stated before, this also saves Tx batteries). Now if you have other trains and operators running on your layout, or if you have track work or other operating conditions that require constant operator attention to avoid derailments, some other action may be desired. 

I do agree, that with track power, you certainly have more options to cut the power to the track in the event of an emergency. In my own experience, the way I operate my layout, every wreck I can remember happened way before I could do anything about it. It didn't matter if it was a Critter Control with hands-on semi-automated operation, track powered radio control (TE), or battery power radio control. I either couldn't physically get to the controls fast enough, or I couldn't even find them (where the (*&#$%#@ remote?). Also, running trains is pretty relaxing. If I'm by myself, I'm probably thinking about something else while the train is running. During an open house or with visitors, I am always engaged in conversations. So the trains have to take care of themselves.


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## Greg Elmassian (Jan 3, 2008)

I like the ideas about fail safe operation. It's funny that this came up because of a claim about a system that does not have it, ha ha. 

Del, not everyone has layouts where if a loco is left running forever nothing happens, I certainly do not, so I think exploring this is a great idea. 

Also, while I agree in some cases the wreck has already "happened", I have many instances where a new person has lost track of their train, and the emergency stop feature really helps. Also, with track power, if you have a wreck, you often have a short circuit, and as anyone knows that has melted out the track pickup wires on their loco, stopping the power ASAP can make the difference between melted wires and circuit boards and no damage. 

DCC has addressed this with CV11, and many people use it on track power and "wireless DCC" like AirWire. 

I hope that Aristo sees fit to make this feature available in the future. 

More "smarts" in the on board receivers/decoders would also be a place to start, might be a way to have the unit do more than just stop, as Michael suggests. 

Anyway, just part of the fun and increased features that could be had with increasing levels of technology. 

Regards, Greg


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## Del Tapparo (Jan 4, 2008)

Posted By Greg Elmassian on 04/08/2009 10:12 AM
Also, with track power, if you have a wreck, you often have a short circuit, and as anyone knows that has melted out the track pickup wires on their loco, stopping the power ASAP can make the difference between melted wires and circuit boards and no damage. 




Aw yes. The track power meltdown! This has created much fodder for conversion to battery power at my house.

And here is one that is unique to battery power .... Loco derails (while you are in the house fetching something), but keeps running under battery power, while grinding a slot into your brass rail with a drive wheel.








Perhaps I need a derailment micro-switch dragging on the rails ...


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## paintjockey (Jan 3, 2008)

Del, my loco (battery power) came off the track when i was in the house and had soooo much grass wound up in the drivers it took me a few hours to get it all out. 

If I remember correctly, with airwire (and probly other DCC) you can also make the loco slow to a stop instead of the "emergency stop". I threw the "E" stop on an aristo train engineer and probly did more damage then if i would have just hit the other train.....


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## Greg Elmassian (Jan 3, 2008)

It might come to an optical sensor to make sure there is actual motion when the wheels are turning... it might be really simple, like the circuitry from a mouse... I wonder... 

Regards, Greg


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## Torby (Jan 2, 2008)

Back when I was in R/C planes, the failsafe was the earth itself. It stops the plane quite effectively


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## Paul Norton (Jan 8, 2008)

The emergency stop is a problem. An immediate stop with a heavy locomotive can be hard on the gears and locomotives are getting heavier all the time. With long trains it’s even worse. The front cars stop, but the back ones just keep on coming. With today’s more detailed cars that can be painfully expensive. 

Setting the momentum to have the train gradually slow down would be easier on the gears, but it increases the chances the train will not stop before impacting something and the cars would just keep on coming. 

So the emergency stop is a problem either way.


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## Greg Elmassian (Jan 3, 2008)

It's less of a problem than crashing into another train, or allowing a short circuit to melt wires and circuit boards. 

I'll take my chances derailing a coupler of cars to keep an expensive loco from smashing into something. 

But of course, since the Aristo and all DCC systems and DCS already have emergency stop, it's clear what the market wants. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

I think there is a difference between an *Emergency Stop* function and a *Failsafe Stop* function. 

RCS has two *Emergency Stop* functions. 
One ramps down rapidly at twice the programmed braking rate to zero output. 
The other ramps down at twice the programmed braking rate to 25% ouput and then stops dead. This helps prevent inadvertent recoupling when switching with Kadees. 
At extreme range super reliable *Emergency Stopping* can be achieved by laying the RCS TX handpiece on the track and pressing *STOP*. The rail carries the signal around to the loco. It only requires a very short *STOP* pulse to be received for the *STOP* to take effect. 

It would be possible to have a program change made so that an option was offered whereby the train could automatically slow and stop after a set period of time if it has not received a command. I tried that once. It required constant reprogramming from one mode to the other depending on how the operator wanted it and was a real pain. So I no longer offer it.


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## East Broad Top (Dec 29, 2007)

I'm thinking the more useful fail-safe for battery R/C would be some kind of orientation switch. Accidents will happen regardless of control. Cabooses will get rear-ended. A fail-safe won't prevent that, only an alert engineer will. However, when a track-powered train derails, it breaks contact and stops. The battery train does not. It keeps going, potentially getting into all sorts of trouble along the way (wedged in a tunnel, roll down an embankment into a pond, plow through the $400 Barnhart log loader...). If there was some kind of safety device that noticed an abrupt change in orientation as you'd have if you derailed, then that could be programmed to send a signal to the receiver to bring things to a very quick halt. That way, once it's off the rails, the wheels (in theory) would stop turning, eliminating the potential for greater harm. 

My first thought would be some kind of mercury switch in line with the batteries, but that would cause too abrupt a stop, causing gear damage as outlined above. (All emergency stops should take a second or so to bring the train to a halt.) Instead, I'd use the orientation software/hardware that's used in digital cameras, levels, etc. to send a signal to the receiver to slow down. That would have to be built into the throttle itself, or perhaps in line with the motor leads if a 3rd-party product. 

Later, 

K


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## TonyWalsham (Jan 2, 2008)

Probably the easiest way to wire up a derail detector would be to have two pick ups on the same side of the loco connected to a "sensing" circuit. 
When it derails the circuit would activate. 
Of course that would only work on uninterrupted track. Really dirty track or "dead" turnouts would be a problem.


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## East Broad Top (Dec 29, 2007)

Of course that would only work on uninterrupted track. Really dirty track or "dead" turnouts would be a problem.

And since running on dirty track is the primary benefit of battery R/C...  

Later, 

K


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## TonyWalsham (Jan 2, 2008)

In other words............ 

Don't worrry about it. 

Drive the things and pay attention to what you are doing.


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## eheading (Jan 5, 2008)

Amen to that, Tony!!!! I truly hope that any RC system that I am considering purchasing, if the manufacturer decides to add a feature that stops a loco when it loses contact with the transmitter, that it does it as an option. I personally would much sooner have the option that keeps the loco running at a constant speed until it gets another input from the transmitter.

Ed


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## Madstang (Jan 4, 2008)

I have used the Airwire system for 2-3 years and have never experienced a "runaway" train.....am I missing something?

There are times while running that the train stops....then I raise the Tx and it starts up again...this usually happens around dinner time 5-7pm

The ONLY thing I HAVE experienced is people falling asleep at the control knob!









Please tell me how to have a ruinaway train as I feel I am missing something!









Bubba


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## Greg Elmassian (Jan 3, 2008)

It's not the AirWire or other DCC based systems Bubba... it's the Aristo TE and other systems. 

CV11 takes care of your problems... just like it does on my track-powered DCC system. 

Regards, Greg


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## East Broad Top (Dec 29, 2007)

Greg, I'm not certain I'm understanding your point. I've been using R/C to control my trains for 25 years, watching my dad design at least three or four generations of R/C throttles before the commercial ones matched his in terms of reliability and flexibility. There are two kinds of radio transmission systems--the first, where the transmitter is continuously transmitting a signal to the receiver, and the second where the transmitter only transmits when a change in status is ordered. The former is what you have with Futaba (or similar) based systems. The receiver is in constant contact with the transmitter, needing instructions on what to do at every nanosecond. Dad engineered his systems to read the signal over a short period of time (1 - 2 seconds) and "average" the signal to determine what the transmitter was actually sending. This was fairly effective in filtering out noise and other reflections. The fail-safe built into that system was that if the signal was too jumbled to be decipherable, it would return to a neutral value since there was no way of keeping track of previous values. 

Systems like RCS and Aristo transmit only when a change of status is ordered (speed up, slow down, blow whistle, etc.). As such the "normal" state of operation for that kind of system is to actually not be in contact with the transmitter. In truth, that kind of exchange between transmitter and receiver is its own fail-safe over a system that has to be in constant contact (and a very big part of the reason why dad ultimately abandoned his own stuff in favor of RCS and Airwire. That, and size and the fact that he didn't have to _build_ each receiver himself.) It's my understanding that DCC works similarly--that it only needs to be in contact with the train to send change-of-status commands, which is why you can unplug your DCC controller to move to another part of the railroad. The CV11 value essentially limits that functionality so you have "x" amount of time to get to the next station. 

Every radio control has an effective range. If--under your normal operating practices--you regularly exceed that range, that's not the fault of the system. The onus is on you to make sure you stay within range of the receiver. Otherwise, switch to a system that has better range. A system maintaining the status quo when not hearing from the transmitter is doing what it's designed to do. The fail-safe for that kind of scenario is something along the lines of periodic bi-directional communication between the transmitter and receiver just to make sure it can still hear and be heard. If the answer is "no" for a determined period of time then a shut-down may be a suitable response. The danger there is that if you've got two trains on the same track--what's worse? A train continuing on its presumed course at a presumed speed, or a train suddenly and unknowingly stopped, only to be slammed in the rear by the next train? 

Later, 

K


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## Greg Elmassian (Jan 3, 2008)

My point was very simple. 

Bubba said he had no problem. 

I said his system uses CV11 as previously discussed. 

The rest of the systems, as you and others have pointed out, do not have a fail-safe type of "monitoring". 

I hear LOUD and CLEAR that many people do not care, or want this feature... That is FINE... 

I just answered Bubba's question factually. This thread and several others are getting emotional because people are very "married" to their systems. 

That is all well and good, but having a technical and objective discussion should not get people all upset. It is my OPINION that it is being interpreted as someone is "dinging" their system choice. 

Just as I appreciate the choices that people have made, my discussion of my choices should not start a war over "whose is better". 

This is the flavor of this thread, the number of triggers thread, etc. A sad tendency on the forum... but that's another thread.

Every piece of data you stated in your post is well understood by me, years ago. 

We are talking about choices here, and none of us need to get defensive about our personal choices, and likewise, we should all stop trying to convince the "other" side to change. (Notice I singled NO ONE OUT, and included myself).

I'm not trying to change anyone, I just try to state facts and when I state an opinion, or personal preference I try to make that painfully obvious... 

So, I like failsafe, many people on this thread think it's not of any use. I want a system with an emergency stop, and some type of failsafe, others do not want it. That's personal preference and opinions. You will not change my mind on what I want, and I will not change yours, and that is not the point. 

I'd rather discuss the technical possibilities, and explore them to learn something by the meeting of all the *great* people here with lots of experience, brainstorming *new* ideas... 

Regards, Greg


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## Madstang (Jan 4, 2008)

I, again must be missing something as I feel no emotion here just people stating fact.


K is stating very interesting fact about his dad's, before-his-time ingenuity, as with his dad he is also of the same caliber, and I hang onto what ever he is working on. 

I see no emotion on his post or mine....again I guess I missed something









I will say that my train sometimes stops for no apperant reason, but I have talked to Al and he stated some facts that, where I live could interfere and cause this problem, gave me some corrective info, and really just cause it stops around dinner time or evening, when people are more apt to use devices that also share the same frequency as the Airwire really give no cause for alarm..just raising the TX makes the train start moving again..I fail to see this as a loss-of-sleep problem!

I will also state that talking to Al is an aquired art, learning to do so opens up a plethera of information one would hate to miss out on! 

IMHO

Bubba


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## Greg Elmassian (Jan 3, 2008)

Bubba, it's all the other threads and accumulations of feelings, an outgrowth of the Aristo TE thread, where I am accused of Aristo Bashing and someone refers to DCC as something nasty. 

It's not you and Kevin at all... in fact just got a call from Kevin on the phone about some programming issues on a QSI of all things... we are fine... 

Regards, Greg


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## East Broad Top (Dec 29, 2007)

Okay, the more I think about it, I'm intrigued with the notion of some kind of orientation sensor-based shut-off. Anyone know anything about that kind of technology? How big is the sensor, how sensative? I'm thinking if there's an application for the iPhone to turn it into a level, there's definitely room for experimentation... 

Later, 

K


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## Del Tapparo (Jan 4, 2008)

There are sensors available. But I think it would be difficult to distinguish a the derailment of one driver where it just leaves the loco cock-eyed on the track for the normal jostling around it gets going through turns and turnouts, and up/down grades. Software filtering make be able to take care of that. This is likely a pricey solution though.


Perhaps the best, easiest, and cheapest solution to implement is what Tony suggested (it was actually my first thought as well); just look at two pickups on the same rail for continuity. When you lose continuity (over some period of time) you probably derailed. I do believe that, just like any alarm system, this could be a nuisance, depending on track conditions and pickups. You certainly wouldn't want to clean track just for this function. 


I may have to try this on my next conversion, if I can remember to keep the track pickups intact. A spare input on the Critter Control and a little software is all it takes.


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## Greg Elmassian (Jan 3, 2008)

Kevin, there are solid state sensors, just think of the one in the iphone that can be used as a level... it would be pretty simple with a microprocessor to detect a tilt angle greater than 10 degrees, etc. Could be easily settable. 

If you did not have a microprocessor, a simple mercury tilt switch to "latch off" the power could be made, just a latching relay or latching circuit and a reset switch. This could be as simple as a DPDT relay, a couple of mercury tilt switches and a push button. 

Regards, Greg


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## East Broad Top (Dec 29, 2007)

A derailment with one wheel off the track isn't that problematic. The rest of the wheels still turn and will guide the train through. I'm thinking along the lines of hitting an obstruction and leaving the rails, either by rolling off the track or rolling askew--the kind of derailments that typically jam our trains crosswise inside of tunnels or push them over onto their sides at switches. If that kind of derailment is noticed prior the train getting too far off the rails, the chance for retrieval without the need for gallons of superglue after the fact would be greatly increased. 

Later, 

K


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## Greg Elmassian (Jan 3, 2008)

I'll bet Del could make a little module up like I described in about 1/2 hour, and they might be a nice product for him to sell. 

Regards, Greg


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## Del Tapparo (Jan 4, 2008)

OK. I give up on "Quick Reply". That's two posts in two days that I have lost into thin air!

Greg - Yes maybe I'll do that. But what I was thinking is using these cheap tilt switches like they use in kid's shoes to flash the lights as they walk. They are about a buck. Discrete input into my Critter Board and some software. I'll give it a go when I get a chance. Man ... retirement just keeps getting busier every day!


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## Greg Elmassian (Jan 3, 2008)

Yep, I thought that the tilt switches should be inexpensive, and you could mount a couple of them at 90 degrees to each other to catch tilt fore/aft and side/side... latch up the relay by hardwiring or of course many more options with a microprocessor... I think it could be pretty cool, and useful in many battery applications... and why not on track applications too? Many times the loco is still getting power when derailed. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg. 
A question. 
When you describe "Fail Safe" are you referring to: 
1. A Fail Safe stop for an individual loco? 
OR 
2. A Fail Safe stop for the whole system?


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## Greg Elmassian (Jan 3, 2008)

This one only for a single loco, as a module that will cut the power if the attitude of the loco is "not normal"... 

(yeah, I can here it now, why don't you strap one to yourself Greg ha ha!.... that is because it would always read not normal) 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Is that "attitude" of the mind or physical positioning? 

I really have considered this "problem", and having seen the "results" unattended locos have on other trains after stopping unexpectedly, I am convinced there is no practical Fail Safe possible for battery powered locos. 
Yes, a Fail Safe can be made to work. Of that there is no doubt. But, it will not prevent another loco crashing into it. 

Even emergency Stop functions have their problems. 
One brand of R/C (not RCS) has a Universal Stop function which caused other trains using the same R/C to suddenly stop at Dave Goodsons RR once. Pity about what happened to the Brass Shay going downhill on a curve on a trestle suddenly having to stop the log train behind it. 

Due to the huge range of non compatible R/C equipment being used at the same time, the onus obviously must come back to the operators to watch out. 
My suggestion. 
Where multiple trains are operating on the same track at the same time under independent control, adopt a form of block occupancy not based on technology. You know, like the old systems the real RR's used. A hand over staff comes to mind. 
 Simple. No more Cornfields. No more rear enders.


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## Greg Elmassian (Jan 3, 2008)

Yes, not a universal solution, and it would stop the motor, or cut power AFTER the derailment. But it would go a long way towards solving the problem Kevin outlined. 

Again, not for everyone, but I think it actually would have broad appeal. In Del's case, it's a small hardware addition and more programming work than anything else... 

Regards, Greg


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## Paul Norton (Jan 8, 2008)

I can only remember one train collision in all the years we have operated on our club layout.

Our dispatcher tracks our trains on a large board to prevent corn field meets. We notify him by radio which train number we are, where we are, which direction we are headed and where we want to go. I received clearance from Peter’s Pond to Bellamy, but had a car derail in a switch at Peter’s Pond which delayed leaving with my train.

In the meantime the dispatcher received a call to cross the diamond near Bellamy from another train and granted clearance. As we both approached the diamond, we both announced that we had clearance but didn’t hit the brakes. Typical males! Fortunately both trains were running slowly and neither engine was damaged.

If there is a way to defeat a failsafe mechanism, people will find it.


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## Greg Elmassian (Jan 3, 2008)

Confrontive text deleted.

I understand you Paul, you don't like the idea, everyone on your layout never has problems, and everyone will try to defeat any failsafe mechanism.

I got it.


I will stop talking about it because it is obviously a bad idea for everyone and not useful at all.

Greg


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## East Broad Top (Dec 29, 2007)

On my dad's railroad, we call it "being acorned." The squirrels have an uncanny ability to drop acrons at the opportune moment to cause the train to go rolling down a 3' embankment. Between that, the gumballs, and the slugs, anything that stops the train once first bumped off the rails would be a welcome addition. 

Later, 

K


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## Paul Norton (Jan 8, 2008)

On the IPP&W it is usually pine cones that cause the problems. I used to run my FA-1 around first because the round pilot would push the big ones aside. Unfortunately the little ones that nestle in the ties can be a problem for Kadee coupler hoses.

Anyone have a railway in Lake Tahoe? As I remember, the pine cones there where about the size of a forty foot car and the trees were very tall. Ouch!


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## Great Western (Jan 2, 2008)

My rule of thumb, but I confess not always followed, is that model trains should be like small children. Observed at all times.


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## eheading (Jan 5, 2008)

I definitely agree with you, Alan. In fact they act like little children also in the fact that as soon as you DON'T watch them, they misbehave!!!!!

Ed


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## Totalwrecker (Feb 26, 2009)

Why not use an optical circuit breaker for a battery Failsafe. Pick a non powered wheel and paint it black and white. When it stops moving while power is applied; after x seconds the circuit opens.... 
I've had derailments that never tipped over on track power and the driving wheels kept on turnin'...


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## Greg Elmassian (Jan 3, 2008)

One difficulty with that type of sensor is that G scale locos and cars often have huge amounts of side to side motion on the axles, so optical sensors are tough to implement. 

But your basic idea sounds nice, basically like an abs system in a car, where you can detect the actual motion of a wheel and compare that to what speed is expected. 

Regards, Greg


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## Del Tapparo (Jan 4, 2008)

While the original intent of this thread was to ask about a programmable fail-safe function, it has evolved into a separate device to perform derailment detection.


This has been a very interesting discussion with some good ideas. I think this function makes sense when it is possible to integrate it into an existing system, such as "CV11" in DCC systems, or perhaps an auxiliary input in other systems. But as far as installing a separate circuit board and sensor(s) to accommodate this function? I don't think many folks would be willing to spend the extra money and more importantly, find the extra space to install this type of device. Yes, I would like to have this function, if it came free with the main system. But I would not bother with a special installation. Would you?


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## Madstang (Jan 4, 2008)

Posted By Del Tapparo on 04/12/2009 9:21 AM
While the original intent of this thread was to ask about a programmable fail-safe function, it has evolved into a separate device to perform derailment detection.


This has been a very interesting discussion with some good ideas. I think this function makes sense when it is possible to integrate it into an existing system, such as "CV11" in DCC systems, or perhaps an auxiliary input in other systems. But as far as installing a separate circuit board and sensor(s) to accommodate this function? I don't think many folks would be willing to spend the extra money and more importantly, find the extra space to install this type of device. Yes, I would like to have this function, if it came free with the main system. But I would not bother with a special installation. Would you?




Finally a voice of reason! This horse is already dead!

Bubba


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## Greg Elmassian (Jan 3, 2008)

If you made it with 2 tilt switches and a relay and a reset pushbutton, it could cost very little, and be relatively small, maybe parts count of $10, but of course more to build in a box and sell. 

Maybe people might want to make it for themselves. Sell cost might have to be $20-30 I guess... 

Regards, Greg


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## GG (Jan 1, 2009)

Greg, 

With my work on my railroad, it would have to be one heck of a tolerant "tilt" switch ! 

gg


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## East Broad Top (Dec 29, 2007)

...But I would not bother with a special installation. Would you?

Yes, I would. When you put the kind of time I do into a locomotive customization, the last thing you want to have to do is do it over again because the loco goes careening off the side of a hill. Heck, it's painful enough on an out-of-the-box loco. I'm already spending upwards of $300 for control and sound electronics to go into the loco. An extra $20 to keep help keep it from going astray? Money well spent. Yes, it's got to be small enough to squeeze in with the rest of the electronics. That's where the solid state sensors and microprocessor come into play. If they can fit DCC into an N-scale locomotive, there's no reason to believe this can't be done on a circuit the size of a quarter. 

...My rule of thumb, but I confess not always followed, is that model trains should be like small children. Observed at all times...

 But the reality is that most of us--even the avid operators--like to sit back, relax with a tall cool one, and just enjoy the railroad. Most of us have tunnels or hidden spots where the train disappears from view; that's part of the inherent charm of a well-conceived track plan. We _can't_ see our trains all the time, quite by design. We rely quite heavily on those two ribbons of brass/steel/aluminum/whatever to bring the train back to where we can see it. Most of the time it works as planned. A system like this is designed for those exceptions. 

Later, 

K


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## Greg Elmassian (Jan 3, 2008)

I guess I will have to build one for someone, and then let them play with it. 

My guess is that if you have a $600 loco with $300 of custom stuff in it, an additional goodie that might save your loco from damage even only 50% of the time would be worth it. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

The problem I find with the logic of using any sort of derail detector, is that it isn't going to actually prevent the derail. 
The best end result you can expect is that it will shut off the power after the derail. 
Like shutting the stable door after the horse has bolted.


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## Madstang (Jan 4, 2008)

All the circuits in the world still do not help cars from careening off a road and or from striking one another..all it does is increases costs, and I might add that this little hobby is costly enough!









Again I will state..."did I miss something"? They only time I have "crashes or trains off the tracks, EXCEPT for little derailments is when somthing is missed on the track or I do not do a walk through prior to running! I rarely have anything like that happen EXCEPT when I let Dangerous Dan Moore run my stuff!









Trains are meant to run if they are that fragile maybe a shelf would be better placement for such an engine....theres a difference between running trains and modeling them.









The answer was stated WAAAAAY back in the beginning of this post....if you watch your trains and do proper walk through prior to running and run with RESPONSIBLE people....maybe accidents may just be a rare thing indeed, and this "failsafe" circuit is a bell and whistle not really needed like the seventies Sky or Space Lab insurance..you know for all of you old enough to remember when it was going to fall to earth but no one knew EXACTLY where, and peole were selling insurance just incase?

You know in case there is a wreck?









Bubba


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## East Broad Top (Dec 29, 2007)

You're correct. Such a system isn't going to prevent derailments--much like airbags don't prevent car accidents. They do keep you from getting seriously messed up as a result. That's what I'm after. I've had trains continue on the ground for one, two, three feet after a derailment, striking rocks or other obstructions, or rolling down an embankment because the wheels keep turning until I realize what happened and hit the "stop" key. It's more along the lines of making sure that while the horse might leave the stable, he's not going to get out of the paddock. That was one advantage of having a trail car. When the coupling came undone after a derailment, the plug pulled out of the socket and the train stopped. 

You can walk the track and be as vigilant or "responsible" as possible--stuff gets knocked onto the track during the regular course of operating a railroad that you don't see until it's too late. Twigs, leaves, and other debris fall from trees on a regular basis. Ballast gets worked into switch points keeping them from closing all the way. Groundcovers reach out and grab hold of valve gear, pulling the train off the rails. Wildlife thinks it has right-of-way. Feet don't quite clear the track as far as necessary. All these things send trains off the rails. I've been doing this for 30 years. Stuff happens. There's no way around it. It's all part of being outside with nature. The best you can do is mitigate the damage. 

A parallel example... You've got a long bridge over a deep pond, or perhaps a high trestle. Putting a guardrail on that bridge is going to take a lot of time, to say nothing of the expense of the extra materials needed. What's the worry? You walk the track before you run trains, and there's nothing around the bridge that could _possibly_ cause a derailment, right? But you also know that by taking the time to install a guardrail, you will greatly increase the likelihood that in case something does go wrong, your trains will stay high and dry. Do you? Don't you? They're your trains. If you don't mind fishing a $4,000 loco out of the drink, save a few pennies on the track work. Me? I'll call it "cheap insurance." 

...if they are that fragile maybe a shelf would be better placement for such an engine....theres a difference between running trains and modeling them...

Forgive me if I take exception to that statement. I know there are inherent risks associated with running highly-detailed models in the garden. It's not a kind environment. I'm not complaining that the models get bumped and bruised in derailments. It happens. It's part of the hobby. I'm merely pondering a piece of technology that might keep them from having unnecessary run-ins with immovable objects. I'd much prefer to spend my modeling time on new projects, not rebuilding old ones. 

Later, 

K


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## eheading (Jan 5, 2008)

Greg, you beat me to it. I was going to say that I have been hearing a lot of good ideas; why doesn't someone design one and individuals can build a "fail safe circuit" if they want it. Sounds like a plan to me!!

Ed


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## Greg Elmassian (Jan 3, 2008)

Ed, you run battery right? What voltage do you run? 

Maybe I will make up something inexpensive... it would be 2 tilt switches, adjustable for tilt, and a small reset button. When the system trips, it would interrupt voltage to the motor, or possibly the entire battery. You hit the reset switch to put it back to normal. 

This is not really a "fail safe", I think that definition is somewhat fuzzy, the intent of this circuit is that if the loco got way off level it would interrupt the power. It would take some experimenting to see if inexpensive mercury switches would do the trick. It could be that the mercury would bounce around too much to be useful... the best implementation would be as Dell mentioned, having a microprocessor in the system, then it could ignore random "blips" but detect an out of level condition that "stayed" for a while. 

Regards, Greg


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## eheading (Jan 5, 2008)

Greg, most of my engines run on the Aristo li-ion battery which is a 21.2 volt battery (24-25 volts max at full charge), although I have a couple running on 19.2 volt ni-mh batteries. I'm not really the guy to ask though, as I personally really am not interesting in a fail-safe mechanism.

What I had in mind was that if someone, like you, came up with a design, East Broadtop could build it and experiment with it to see if it would fit his needs.

Ed


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## Totalwrecker (Feb 26, 2009)

Posted By Greg Elmassian on 04/11/2009 10:37 PM
One difficulty with that type of sensor is that G scale locos and cars often have huge amounts of side to side motion on the axles, so optical sensors are tough to implement. 

But your basic idea sounds nice, basically like an abs system in a car, where you can detect the actual motion of a wheel and compare that to what speed is expected. 

Regards, Greg


Probably should have said; axle, half an inch wide; half black half white. Making it wider than the sensor (1/4) easily allows for wheel slop. This is the trigger for my sound system which was designed to run on it's own battery thus no electrical interface.

Or one axle could be shimmed to avoid extra motion....

You DCC guys could have a deadman's button on your controller.... that's realism!

Be Well.

John


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## TonyWalsham (Jan 2, 2008)

John. 
I assume by a *deadman's button* you mean an emergency stop function. 
If so, pretty well all battery R/C systems have such a function. RCS certainly does have such a STOP function. 
I can see the sense of having an automatic function that turns off the battery power *after* the derailment has occurred. 
If the loco was self contained, the idea of a stripe reader on a non powered axle is fine, except it would really only work with a tender on a steam loco. Not with a dismal where all axles are powered. 

The tilt sensor could be OK as could a circuit sense through wheels on the same side. Both have positives and negatives. 

The actual power interrupt circuit is quite straighforward. Does anyone have any other ideas for a sensor?


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## ConrailRay (Jan 2, 2008)

You can probably use an analog 2 axis accelerometer that outputs variable voltages based upon the tilt that you may be able to measure with an adjustable voltage comparitor circuit to trigger the cut-out relay. 
The digital version will ouput pwm that would be easy to pull into a uproc and compare, or maybe measure it with a 555 timer circuit so a uproc doesn't need to be used? 

Many laptops now have these in them which will tell if you drop your notebook, and it will turn off the hardrive so it doesn't scratch up the platters. 
There some examples schematics on dimensionengineering website for the unit that they sell. 
http://www.dimensionengineering.com/accelerometers.htm 

Also, I bet you can wire in pressure switches to the contact sliders (if anyone is still using those). ie, when the train derails, that contact foot should slide out farther. 

-Ray


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## Greg Elmassian (Jan 3, 2008)

The best idea would be a combination of accelerometers and the solid state level sensors... then you could determine absolute attitude and also acceleration or lack of... 

I think all these sensors are pretty cheap now... 

Regards, Greg


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## ConrailRay (Jan 2, 2008)

Also, what about using IR leds and sensors? If you shoot the IR led directly down on the rail head, it should bouce back up where the sensor would detect it. If the train derailed, maybe it would not bounce back (guess its depends on how IR bounces off different types of materials) and could trip a relay which is a realy simple break-beam detector circuit.... 

-Ray


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## Greg Elmassian (Jan 3, 2008)

Probably too sensitive to ambient liight, reflections, etc.... 

Greg


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## Totalwrecker (Feb 26, 2009)

Actually on the 1:1's here they have a button or controler they have to hit every so often or the train goes into emergency. Some steamers had a similar arrangement and the joke was to carry a brick in your lunch pail to keep it happy. 

Not all derailments hit the sleepers, not all tilt, some drag a wheel until they clear all embankments and can dive off just before the bridge....lol

I think a circuit that senses change in motor amperage + - would cover the most bases.

Dismals! nice, I like... trailing cars could have a socket for a sensor.


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