I was using all P2K wheelsets except for the odd car here or there that needed a different axle length. That worked out great until I started adding resistors to wheels for detection on the club layout - the slippery plastic used for the axles is not your friend here. Though I did get them to work reliably and so far they have held up - mainly because after they were workign I sprayed the axles with flat black paint to seal in the conductive paint.
In the future I will probably use Intermountain wheelsets - the axle is also metal, so you can just glue on a surface mount resistor at an angle bridging the insulating ring around the one wheel.
TO do the P2K's, I used I think 0603 size SMD resistors. A TINY drop of super glue glues them to the middle of the axle - if the glue oozes over the ends, it will insulate the connections and it will never work. I use thick CA and a toothpick to put the tiniest of dabs on the axle and then set the resistor in place with forceps.
Oh, before gluing on the resistor, I take a small burr in my dremel and scratch off the blacking on the back of each wheel, and also to rough up a line across the axle in line with the cleared spots on the wheels. The resistor gets glued in the middle of the roughed up line.
I picked up some silver paint on eBay - warning, this stuff is not cheap, but I got the smallest bottle and did over 100 wheel sets and still had half of i left. It may have dried up now that it's been sitting for a couple or years. I got the stuff that is 18% silver - yes, it's real silver. I think next time I will get the 36% silver, but the 18% worked fine. It's sold for use with electron microscopes.
I use 10K resistors - 2 axles per car. The club standard is a single 4.7K per car, but at least on longer cars I like to have both ends detectable if it spans a block boundary, and the detectors we have will detect a single 10K across the tracks. If the whole car is in the same block, it has an effective 5K, 2x 10K in parallel.
AFter the CA dries, I paint a line from each end of the resistor to the wheel with the silver paint. This is where the slippery plastic is a pain - even rouched up, the silver tends to be repelled. DOn't try to slop too much on at a time, if ti runs under the resistor or over it you now have a short. I usually do two coats before it appears like there is a solid silver line. Then you need to let it fully dry - the first few I made I thought I was messing them up since I put them on a piece of track connected to my multimeter and was getting open circuit no matter how much I slid the wheels around. It takes 15-20 minutes or more for the paint I used to actually dry - at which point I started geting the expected 10K resistance, give or take the 10% tolerance of the resistors. I also found that to work flawlessly withotu applying weight to the wheels, I needed to polish the treads, I did this with the fiber wire (not the steel fiber) wire wheel in my dremel. Unpoliched, even with two wheelsets (that tested good) in a car that was actually slightly over the NMRA weight, I would ahev to push down ont eh car to get the resistance to read. After polishing the treads - just the weight of the car gave successful reads. WHen I have a workign wheelset, I put it in my wheel painting jig and spray over the conductive paint and resistor with some cheap flat black so you don;t have this silver band flashign under the car as it runs.
It took me way longer to type this than it does to make a resistor wheelset (not counting the waiting for paint to dry). The first few went kind of slow but once I got the hang of it I breezed through the rest of them. My one wheel painting jig holds 4 wheelsets each easily accessible (the other hold 8, but 4 of them are below the other 4 so you cna;t really reach in to glue resistors). So I load up 4 wheelsets, do the Dremel part, glue the resistors on amd while waiting for the CA to dry I do the next 4. Then back to the first 4 and paint the silver paint on. Then they get set on the test track connected to the multimeter until I get a reading.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Yes Dick is a great guy and has helped a ton. I already have a list from him on what I need. Also ordered the two MR Craftsman mags with the signal articles in them. Waiting for Atlas to finish the BLMA take over so I can start ordering signals. I really like BLMA's stuff.
Two questions now for you guys. Do you have a brand or style of wheel resistor you like? I know there was a couple different styles out there and ways of doing it.......
And any recommendations on blocks? Setting them up? Or where they should be?
I'm still struggling since it's just a round donut style set up of not going crazy and putting 30 signals on a layout. I want to see more than just signals......
Mike
Dick should steer you right as far as the products to use. He runs a good business. Several years ago he was at the Timonium MD train show and I think I ended up spending 2+ hours sitting at his booth talking train electronics with him and getting demos of his products. The club layout has several of his Tower Controllers and the BOD-8 current transformer detectors.
Stix--Yes, definitely going to pick those up! Will definitely help.
Been talking a lot with Dick from RR-Cirkits. Not only some good products but so far top notch customer support and he's been extremely helpful in helping me figure out what is needed and will work best for me. So I appreciate the recommendation to hit him up. Good call for sure.
The main problem I'm having is it's such a small layout with a spiderweb of track. This whole process would be sooooo much easier if I had my 40,000 sq ft shop with a 3' shelf layout running the entire perimeter of the place! But no. I had to crap 300' of track into a garage! LOL! It will be worth it though.
But it's definitely very difficult to not have signals on top of signals yet still make everything work how it is supposed to. Some areas I'm just going to have to omit singals just for overcrowding reasons and will have to deal with it. Only my die hard RR buddies will realize it but it's just what it is.
It seems like the wiring and all that will be time consuming but overall cake. Figuring out blocks though is about to give me an aneurysm! There again with such a small layout it's tough to figure out what goes where and where double signals need to be an singals......
We'll get it though. Just trying to do it in baby steps!
Just got the Jan 2016 RMC in the mail last night, with part two of Bruce Chubb's series on signalling. I'd again strongly suggest you pick this issue and the Dec 2015 RMC up. Lots of good information on real signals, and model signalling with computers.
Man. So much to think about. But you guys have successfully convinced me.
I think the hardest part now will be to figure out where I need signals. It's really hard since the layout is an oversized donut.....just what I have to work with for room. And dad and I like to run trains so there's lots of track to run around on. That will be my first step.
I also designed the layout in AnyRail which I know transfers right over to JMRI which will be one less step.
I also planned ahead just in case I did want to do block detection and wired a drop off of every piece of track on the layout. So it's sounding like once I have my blocks cut out I can just go in and put the block detector on one track lead and call it done.
I like the idea of the delay. I really want three color signals. Green open, red as it passes through and when the next signal up the line goes yellow the signal before goes green. Just like the real thing.
I have used the Caboose Industry ground throws for all the switches. I know they have one that has a sensor in it as well. I can always switch out whatever switches I need to with that for JMRI to recognize what color needs to be shown where for what track.
I can't thank you guys enough for your input. I am definitely going with block detection now. And I'm going to head to RR-Cirkits to see what they have. I defintely like having it's own power source for all the signal stuff.
5150WS6 All my switches are hand throws as well. So I won't have any of those electronically controlled. At least not at this point.
All my switches are hand throws as well. So I won't have any of those electronically controlled. At least not at this point.
You can buy manual ground throws for turnouts that have contacts attached, so your system can 'see' which way the turnout is thrown. Railroads use signals both to indicate block occupancy and routing - green-over-red means you're continuing on the mainline, red-over-green means your leaving the main and going on a branchline, or to an interchange with another railroad, etc.
p.s. whichever system you use (track detection, infra-red, light sensors) get a system that has some type of 'delay' setting. We've all seen layouts where the train passes a green signal and it changes to red...then green...then red...then green over and over as the train goes by, because the track occupancy is momentarily cutting out. With a delay, you can set it so once the block signals turn red, they stay red for say 2 seconds. That way, a momentary contact loss doesn't make the signal flicker back to green for an instant.
At least for block detection, the RR-CirKits stuff (or anyone's transformer detector) will probably play better with a non-Digitrax DCC system since it will not electrically connect to the track power like a BDL-168, and the BDL-168 is also somewhat dependent on the railsync signal in the Loconet cable, which in a Digitrax system is a low power mirror of the DCC track signal - you won;t have that linking one up to an NCE system. The transformer detectors work by sensing a current flow through the wire. It doesn't matter if this current flow is from NCE, Digitrax, Lenz, MRC, or any other DCC system. Or in some cases, AC hi rail.
You are welcome. For NCE ... I really don't know this system at all. But as Randy said, I know of at least two people here on the forum who use Digitrax loconet for signal/turnout control on a layout that is NCE for DCC and engine control ... Perhaps one would chime in.
This would mean you would need a way for JMRI to know the switch position some other way ... If you want signals to respond based on switch alignment. I think RR-circuits makes a board for this.
5150WS6 So answer me this. On the BDL168. Or any signal detector. I have leads or feeds already coming off each section of track. Do one or both wires need to go in or through the BDL168?
Take a look at Randy's comments on RR Circuits. Maybe plays better with NCE? I went with Digitrax simply because I already had a starter command station (the DCS51 Zephyr Extra) and so it was logical for me to start buying more Digitrax.
Hope this helps.
Here's another option for detecting cars. At our club we mixed up a batch of flat black paint and graphite. This was painted on one axle of each car from wheel to wheel. After the paint dried we scraped some of the paint off until we had about 1000 ohms of resistance. This has worked fine with first the Twin T system and later on with Digitrax. I'm not 100% sure of the exact ohms we were shooting for as it's been about 30 years ago when we did it. But I'm going to the club in a while and I'll check and update this when I get back.
Each detection section gets gapped on one rail. The other rail remains continuous unless you have multiple boosters, in which case both rails are gapped at that border, same as always - adding signaling and detection does not change the basic power wiring rules.
I also suggest you take a look at RR-CirKits. Their devices are broken down into logical units that include the detection, turnout motor drive, and signal drives for specific sections of the layout. Plus they use transformer detection, which does not reduce the track voltage like diode drop detection in the BDL-168.
It's fairly common for people to use NCE to run the trains but Digitrax (or equivalent Loconet products, such as the RR-CirKits components) for the signalling and dectection - while NCE has a few items that can be used, like the AIU and the BD20 block detectors, the NCE bus really can't handle the traffic of all the detections and signal drivers on a busy layout.
To figure out exactly where things go, and how much equipment you will need, you need to understand signaling itself. Once you've figured out where it is logical to place signals, you can start to see where you need to set the block boundaries to detect a train to be able to set the signals to the correct aspect. Once you have an idea of how many signal heads you need and how many blocks, then you can calculate how many of a given circuit board you need to be able to handle those counts.
Running it all with JMRI is great, because JMRI can simultaneous hook up to your NCE system to use throttles and do programming while also hooking up to the Loconet to read the bloc detectors and set the signals. All at the same time.
And if it makes you feel somehow 'dirty' connecting Brand D equipment to your Brand N equipment - that's where companies like RR-CirKits come in. Digitrax has more third party support than all the others combined, so you can put together a Loconet signal system and not use any products actually made by Digitrax.
The Carolina Southern Division of the National Model Railroad Association runs wonderful Set of classes every January. I have learned a great deal in those classes.
I use current detection. PR3, BDL168, RD2s, and SE8C. The BDL168 also triggers 3 grade crossing signals via DS64s. I purchased a couple of resistor wheel sets, but now make my own with super glue and conductive paint.
Dave
Lackawanna Route of the Phoebe Snow
NP,
Thank you. Pretty much exactly what I was looking for. Basically a grocery list. And that was my bad for not giving more details. My DCC system is all NCE. Pretty happy with their stuff. But I'm assuming Digitrax is just as good for the signal system.
I also designed the layout with AnyRail and heard that you can import the track design directly too JMRI. And I already have it downloaded to my laptop.
And I've got 300' of track.....that's going to take some figuring on where I want to have the sections. But technically for the signals to work correctly all those sections must be connected together correct? More or less?
It doesn't seem nearly as overwhelming now that you sort of spell it out that way. So answer me this. On the BDL168. Or any signal detector. I have leads or feeds already coming off each section of track. Do one or both wires need to go in or through the BDL168?
Thanks again for the input. You guys might be converting me to block detection......
5150WS6 Does anyone know of a stupid simple crayon and construction paper type drawing is of what's needed and how it all goes together? I'd like to see just how the pc set up is wired and where things go and how many are needed......
Does anyone know of a stupid simple crayon and construction paper type drawing is of what's needed and how it all goes together? I'd like to see just how the pc set up is wired and where things go and how many are needed......
I have words. The kids broke the crayons. At this point I don't know what type of DCC system you will have, so I will assume Digitrax ... since they are the only one I know who make all components to pull this together ... Except for the actual signal lights.
Step 1: Connect a computer to your layout
Purchase a Digitrax PR3 and connect it to you command station (base unit) via a loconet cable (LNC162). The Digitrax PR3 has a USB cable. Follow PR3 instructions carefully to make sure the drivers are installed correctly. Now download and install JMRI. You will need to tell it the kind of system you have, but typically in 15 minutes you should be able to control an Engine.
Step 2: Set up detection
Buy a Digitrax BDL168. Divide your layout in sections and connect each section to the BDL168. Of the two wires coming out of the command station, one can go to track as before. The other must pass thru the BDL168. Of course the sections will need to be separated electrically. The BDL168 has 16 sections ... And once you connect it to the loco-net, the JMRI will see 16 sensors in Tools > Tables > Sensors menu. They will show "active" or "inactive" based on occupancy.
Step 3: Set up a signal controller.
Buy a Digitrax SE8C ... This one is a tough one ... But once connected to loconet and once you attach a signal to it (they give you a test signal), you can select a switch (eg #257) and set it to closed and thrown to effect the aspect of the signal. The SE8C supports 32 independent signal heads. It also supports 8 slow-motion turnout controllers so you can throw switches.
Step 4: Purchase and wire your actual signals. Place them at the locations you want and connect them to the SE8C.
Step 5: Create signal logic In JMRI.
Using the "Logix" function, build logic for the signal. You can do things like: "if block 2 is inactive and switch 5 is thrown and signal 1 is not red then show Green".
Yep ..l its that easy. But it's all worth it when you first see a train pass by and your signal reacting to it.
NP.
Why has no one asked....
DCC or DC?
DCC: this is simple as it gets. There are tons of youtube videos online: http://www.digitrax.com/products/detection-signaling/
DC: http://www.gatewaynmra.org/electrical-electronics/
Your choices are current dectection, relay detection, IR detection, and photo detection.
three color signals are similarly wired in a cascade fashion above. Red connects to yellow on the next block.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Well that explains it somewhat. I didn;t say you were bashing current detection, just wondering what problems you had that made you not like it as much. Twin-T says it all. Yes, at one time that's all there was (and some really oddball other options using relays, and variations with one transistor and a diode, etc). Part of how it worked though is that it was specific to the transistor characteristics - and affordable transistors in the 50's were hardly top quality parts - even the cheapest junk parts from China these days have better characteristics. So Twin-T was designed to work around all that. Biggest problem with DC is that when the train stops, the power is off, so that has to be fixed. AND when you go in reverse, the polarity is reversed. Also designed into the circuit. DCC is MUCH easier - the power is always on, and you only have to measure on one side of the waveform. The modern equivalent of the Twin-T uses the drop across a diode pair. Still has the same problem - it drops the voltage to the track, though by less than the Twin-T. Half, in fact - 1 diode junction rather than 2. Still not good enough for me. Along comes the current transformer - several commercial DCC detectors use this as well as several DIY projects. Now there is no voltage drop, but these will not work on DC.
IR optical detection works great for fixed position detection - staging tracks, setting off crossing gates, etc. Better for those uses than current detection. My layout will have both kinds as needed.
Using the computer for the "logic" part is generally easier that the crazy programming to set up the same sort of logic in a device that has only a couple of buttons or needs CVs programmed to define the logic. Once it is set up, it's automatic - you aren't constantly fiddling with the computer unless you want to make changes to the logic rules. You CAN also set it up so the computer acts as a CTC panel to line switches and set signals, but it doesn;t have to do this, it can simply process inputs from the detectors and switch positions and send out the signals to light the appropriate signals.
Stix,
Well I'm not totally against the pc idea actually. In fact I wouldn't mind going that route at all as long as it's all fully automated. I don't want to have to worry about driving locos and working signals at the same time. Guess that was more the reason for the infrared type signals.
And yes I know that JMRI is an amazing program once you get it up and going. But unfortunately there are a couple problems with that part of the technology. My dad and I are doing this. Now while my dad is a pretty sharp guy at 74, getting him to wrap his head around the DCC thing is almost overwhelming at some points.....as it is for me. This is our first layout since I was single digits.....back when track was brass and DC.
The learning curve for that stuff seems rather high too. I'm just getting to understand all the DCC stuff and CV's and programming consists and yada yada. With a 50 hour a week job at this point I'm not sure I have the time or the patience to sit and work out the JMRI stuff as well. I think it will come down to cost mostly as well. It seems overall much cheaper to head the route of the infrared vs the current type block detection. But maybe you guys that have done the current style can confirm that as I'm still not totally clear as to what all is involved. I know you have to have the current sensors for the block, then you have to have multiple sets of signal controllers and then the signals themselves. Now that I say it out loud I guess it's the same with the infrared more or less.
I guess going the pc route seems a little more daunting than maybe it is. I'm an IT guy and build all my own pc's as well as have some good electrical background, so I'm no slouch......but I'm also OCD so I have to have it all run perfect! LOL!I will grab the issue of RMC. Read stuff from Bruce for years now so that will be an eye opener for sure. Thanks for the info on that!
Going back to the OP, a couple of points....
First, why don't you want to use a computer? With the available programs you can make things much easier than doing an old-fashioned set up with a bank of relays. Use JMRI interface on a computer and you can do a lot of things much easier than using older technology.
Second, Z-Stuff signals by themselves are probably going to give you the appearance of a working signal system, more than an actual working system. Again, using a PC or laptop to control things is going to be handy. Plus, I'm not sure the big base Z-Stuff uses for their sensors is less obtrusive than a small hole in the ballast here or there.
Last, I'd suggest picking up the Dec 2015 RMC. It's starting a series of articles by Bruce Chubb on signalling a model railroad. As he points out, before installing a signal system, you have to understand how real railroad signals work. It's much more complicated than the automobile 'red means stop, green means go' road lights. Red sometimes means an absolute stop, sometimes 'stop and proceed', and sometimes 'slow way down'. Also, you're going to need some double-head interlocking signals where two lines come together or split apart, or in some other situations. These tell your engine crew whether their train is continuing straight on the mainline, or heading off on the branchline, or which track they'll be on when switching from single track to double track.
p.s. If you go with track sensors, you can buy wheelsets now that have the resistor already installed. One per car is usually sufficient.
rrinker Not sure what Mel's issue is with current detection, but it is highly reliable, and if you get at least a few cars besides cabooses fitted with resistor wheels, you stand a chance of actually holding the block indication red if the train comes apart in the middle of one. --Randy
Not sure what Mel's issue is with current detection, but it is highly reliable, and if you get at least a few cars besides cabooses fitted with resistor wheels, you stand a chance of actually holding the block indication red if the train comes apart in the middle of one.
Really depends on what you are trying to do. "Pretend" signals controlled by something like the Logic Rail Signal Animator, optical dectecots are fine. If you want the signal reading based on actual occupancy of the block, current sense detectors are the way to go. Not sure what Mel's issue is with current detection, but it is highly reliable, and if you get at least a few cars besides cabooses fitted with resistor wheels, you stand a chance of actually holding the block indication red if the train comes apart in the middle of one. The best sort, at least if you are using DCC, uses a small transformer to detect the presence of the locos and resistor wheels without actually causing a voltage drop. Diode types work fine, but they do cause a voltage drop, so if you have undetected blocks, you usually have to still have the detection diodes even if nothing is actually hooked up to them so the voltage remains consistent between blocks.
Mel....an SP guy. Knew I liked you! :)
I'm still leaning towards the optical. As much as I hate the idea of having to hide sensors, I hate the idea of not only purchasing but wiring in all the current sensors needed to make the layout work properly. That along with the cost. The optical would be a lot cheaper just because I wouldn't need so many sensors as I would for the current version.
We'll see. Still not 100% but the optical is more what I'm leaning to. Just seems a little more user friendly at this point. I've been in railroading for 40 years but this is my dad and I's first layout in DCC so the learning curve there is big for us. I'd love to get a JMRI set up at some point, but that's a long way off. Looking for a simple and good working sytem at this time.
An optical detection system does require several beams on curved track, the max on my layout is four beams for the solid red and green blocks on my diagram because of the complex curved route. The dashed tracks are hidden in my mountains.
If you are using the induction coil devices, the powerfeed wire goes through the coil and would have to connect to all the pigtails that are associated with the section that is to be monitored. So if you had a passing siding, you would need one coil for the main, and one coil for the siding. I think each turnout would probably be block by itself, but I'm not totally sure.
By the way, if you look at the second video he shows how he wires the block detectors: https://www.youtube.com/watch?v=8ZZ3VGPQzms
Oh ok, that would be easier for sure. I do have metal wheels on all cars already so that parts done.
So for the current sensors.....I wired a feed to every piece of track on my layout. Could I just attach the sensor wire to my pigtails coming off the track?
5150WS6 Other than the fact it would involve wiring resistors on a every stinkin car I have.
Actually you would not be wiring anything. What they do is lay a small (surface mount?) resistor between the metal axle and the back of the wheel across the insulation. There is a product I believe is called wire glue that is used to afix the resistor in place.
I'm sure that there must be a youtube video somewhere showing the process. You do need metal wheels/axles however.
Edit: Here's a link to a guy doing it in N scale: https://www.youtube.com/watch?v=xVshMV6Hb_Q
However, I think that the wire glue method probably works better than the conductive paint product he is using.
LION uses 48 wheel pickup on the trains of him. 14 miles of track. Lots of signals.
LION uses relays for his signals. No mystery black chips for this felid.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Actually that's a good point too. Other than the fact it would involve wiring resistors on a every stinkin car I have. That would take forever. But you're right. Have an uncouple and the photo sensor thing isn't the best option.
Hmmmm. Now I'm back on the fence.